The View Up Here

Publishing on Blurb - Part 1

2009-05-18T12:43:00.001-07:00

In an earlier post I mentioned that I'm editing a book of KAP images to be published by Blurb. I'm excited about doing this project, though the learning curve has been a little steep. This is my first book, and my first experience editing other people's pictures. It's an ongoing story, but it starts here:

The first time I heard of Blurb was during Worldwide KAP Weekend 2008, when Peter Neville offered to take a collection of images from each of the photographers involved in WWKW and publish their photography as a book. Peter used Blurb, a company that does print-on-demand for books. The result was a very professional book that is fun to look at, regardless of the fact that I have two pages of images in it. So when Worldwide KAP Weekend was extended to Worldwide KAP Week in 2009, and when no one else stepped forward to edit the book, I did.

I had already been planning to publish a book of aerial pictures of Hawai`i, but at this time I really don't have enough pictures to justify putting a book together. My goal is to have at least five hundred print-ready pictures to cull through. I figured if it doesn't hurt when I cut out 2/3 of the pictures, I didn't bring enough good work to the table in the first place. So editing the book for WWKW 2009 makes for a good dry-run on my own book, and gives me the opportunity to work with other photographers.

In reading through the forums on Blurb, what became apparent very quickly is that photo editing can make or break a photo book. There is no one standard to move from a digital camera to a digital darkroom to a digital printer. What you see on the camera often bears very little resemblance to what comes off the printer. There are tricks involved. And that's where the learning curve really took off.

The first stage is to put all the images into sRGB color space. This is the color space used by the Epson printers that Blurb uses for printing its books, so the images will wind up in this color space eventually anyway. It's better to put them there first so that all the subsequent editing is representative of what the printer will see. Many cameras can be told to use sRGB color space, which is even better. For my own work, this is what I plan to do. For the WWKW 2009 book, I have to take what I'm given. Conversion first.

The next stage is to get an idea of what the printer will produce. This is where it starts to get tricky. There are two parts to this problem: The first is to make sure the monitor displays in a consistent standardized way. The way to do this is to get a colorimeter and monitor calibration program, and to use it religiously. I wound up getting a Spyder2 colorimeter with the Spyder2Express software. I spent an afternoon madly calibrating all the monitors in my house, and now when I start Photoshop on any of them and bring up a given image, they all render almost identically in terms of contrast, brightness, and color temperature. So far so good.

The second part to the problem is to get the ICC profile for the printers and paper Blurb uses, and to compare the images against it. Keep in mind that no actual image conversion is done at this stage. This just simulates, on a calibrated monitor, what a given image file will look like once it is printed on that printer using that paper and ink. It's not a substitute for an actual printed sample, but a good ICC profile used on a properly calibrated monitor is supposed to be pretty darned good.

The third part, of course, is to get a printed sample to compare against. So I spent most of my weekend putting together a 36 page test book with a number of images that could cause problems when printing. The book has been ordered, and should be here in a week or two. That's just in time for when submissions for the WWKW 2009 book are closed.

In going through the problem pictures for the test book, I ran into a couple of things I expect to see more of when putting the WWKW book together:

A number of images had patches of color that could not be reproduced on Blurb's Epson printers. When a color is outside the range of what a printer or monitor can reproduce, it's said to be outside of that device's color gamut, and that part of the image is said to be a gamut overrun. A lot of what I did with these images was trying various ways to get the colors back into gamut so that they print accurately. It wasn't possible in every case, and a number of images in the test book have patches that are outside of the printer's gamut. In some cases this was intentional, so I could see how the printer handled it. From what I gather it's like having a shadow area in an enlarger print that is just too dark for the paper to handle. It winds up looking muddy, with little to no detail. We'll see.

A number of other images had strong shadows that wanted to block up. "Blocked up" shadows are shadows with little or no detail. When detail does show up, it's typically a result of irregularities in the print medium or in image compression rather than any real details in the image itself. The result looks muddy and unattractive. In processing these, I did what I could to boost the level of the shadows enough that real details showed up when previewing the images using the Blurb ICC profile.

The counterpart to blocked up shadows is blown out highlights. In four color printing that basically means that no ink touches the page, and the underlying paper is the only representation at that point in the picture. No detail, no nothing. The trick here is to try to bring highlights down enough that texture and detail is preserved when previewing the images using the Blurb ICC profile.

One oddity that came up during this was a particular B&W image I used for highlight testing. I used it in two instances, one when doing color correcting, and one for comparing two choices in background. During the color correction comparison, the image was saved as an sRGB JPG for both the test image and the control. The test image had +1 green added to it to counter the magenta shift the Blurb printers seem to have.

But in the case of the background test, the image was saved as a grayscale JPG for one page, and as an sRGB JPG for the other. The images look very different once loaded into the Booksmart software. For the record, Blurb makes quite clear that all images are fed to the printers as sRGB JPGs. But when Booksmart does the conversion from grayscale to sRGB, it apparently shifts the gray scale values by quite a bit when compared to how Photoshop does the conversion. This is important to keep in mind when handling B&W images. The conversion to sRGB color space really does have to happen as the first step, or an uncontrolled conversion will happen later.

Other pages in the book test two page full bleed spreads, two page subframed spreads, tiled images, etc. I couldn't test every situation I'm likely to run into, but I tested quite a few of them. Even if the text in the test book is of no interest to anyone other than me, since it describes the details of each test, I hope the photography in the book is of interest, and that someone other than me will be interested in seeing it.

The test book should be here in one to two weeks. In the meanwhile submissions for the WWKW 2009 book open in three days, and I've got a lot of disk space to clear up before that happens. No matter what, one thing I learned while making the test book is that 90% of the work for the WWKW book will be spent preparing the images in Photoshop. I have a procedure for compensating the images for color shift, but each one of the images in the test book took a lot of manual manipulation to get the most out of them. There are no shortcuts.

But I'm looking forward to it.

Tom

Workflow

2009-05-17T12:21:00.001-07:00

Worldwide KAP Week 2009 was a big success for me. I had all manner of plans for places to fly and things to do, but I only managed to visit a small percentage of the sites on my list. I even caught a cold in the middle of WWKW and lost half the available days to it. Nonetheless I came home with a number of images I'm quite happy with, so I call it an unqualified success.

Last year Peter Neville very kindly offered to edit a book of WWKW images, and so the participants were later able to order a copy and have something to show to their friends, family, and people curious about KAP. No one came forward this year to edit the book, so I did. It's been a whirlwind learning experience, but a good one. And once the images start coming in the learning experience will only ramp up. But so will the fun! So it's all good.

The best part of this is that it's forced me to re-examine my own workflow. I found some flaws in what I've been doing in the past, so here's an opportunity to set the record straight:

The Camera

At the moment I'm still shooting JPG files. I know, I know, RAW is better in oh so many ways. But with the Canon compact cameras, I'm not convinced the benefits are all that huge. The biggest one, for me, is that the images don't have JPG compression artifacts in them. This allows a lot more latitude in image processing, but at a cost: the files are huge. On the ground this isn't a huge problem, but in the air it's difficult to know when your chip is full and to know when to swap chips. The result can be lost images. At some point I might make this change, but not now.

The Computer

As soon as I come home from a session, all images from all chips are dumped to my computer and erased off the chips. At this point I pop out all my batteries and load them into chargers. By the time I make a first pass at the images, my batteries are charged, my chips are all empty, and my bag is re-packed and ready to go again.

Original images are kept pristine. I don't like to make changes I can't un-do. Regardless of whether this is done in software, such as with Adobe Lightroom, or if it's done manually through a system of copying and saving that preserves the original file, this is important.

Once the images are on my computer I sit down with my KAP notebook and start going through the pictures. Clear winners are noted by image number and subject name. Sets of images that might work well as a composite stitch are noted as well, along with the subject name. I don't erase bad shots or non-keepers. These can still be used later in the process.

At this point I'll go back through the composite sets and look for signs of parallax shift. Tall thin things are the toughest since they tolerate almost no camera shfit. But if anything is obviously off, that set is either modified or scrapped. As each one clears this Mark I Eyeball check, I'll load it into my pano stitching software and give it a go. All panos are saved without cropping, full size and checked for anomalies. Sometimes these can be fixed in Photoshop. Sometimes they're too extensive and have to be scrapped. Scrapped composites get a line through them in my notebook.

The next step is to load the images into Photoshop one by one. I like to start with the composites because they're the trickiest to work with. That leaves the single frame images for the end, which is pure pleasure. No stitching anomalies to worry about, just straight darkroom editing.

Most of the time with the composites is spent with the rubber stamp tool, trying to repair anomalies. I'm fairly conservative about this, and will scrap a composite rather than edit out a bunch of anomalies. If I can tell it's been re-worked, so can anyone else. But this is why I don't crop first. If you can rubber stamp areas that are going to be cropped out later, it's a lot less obvious to the viewer later. Waste not.

Once the composites are repaired and cropped, I'll save them without further editing. At this point they're essentially a single frame image and can be treated that way.

Single frame images start by getting geometric corrections. PTLens is great for this. It will take out barrel or pincushion distortion, and can apply the geometric effects of the tilts and shifts available on a view camera. If an image has a strong horizontal or vertical, this can be an essential step in the process. Curved horizons just plain aren't believable to me unless the picture was taken from the stratosphere or from orbit.

Composites with curved horizons or tilted verticals typically go back to the stitching software for repair. Most have the ability to re-tune the projection of the image and take out things like curved horizons. If a composite needs repair of this sort I'll re-stitch it, tweak the projection, and once again save full size without cropping.

Back in Photoshop, the next step is to crop the image for composition. With a camera on a tripod, the photographer has a great deal of say in how the image is composed. With a camera on a KAP rig, even one with video feedback, there's a random element involved. The camera is never pointed quite the way you want, so the resulting images almost always need some form of cropping. With KAP, this is when I start looking at placing subjects on the 1/3 lines, when I start looking at leading lines and golden mean curves, and when I start looking for balance and motion. On the ground all this happens at the viewfinder or on the ground glass. But for KAP the real art starts in the darkroom or on the computer.

When cropping it is important to keep your final print product in mind. If this is for an 8x10, it needs to be cropped to that ratio. If it's for a CD cover, the ratio needs to be square. If it's for a poster, you need to know the dimensions of the poster, or the image area of the poster to be precise. And if it's for some indeterminate purpose like monitor wallpapers, you may not be able to crop at all. In those cases it's better to leave your options open.

Once the images are cropped, I'll save them under their new names, by subject. "Kua Bay Abstract" "Boogie in the Big Blue" "Can I Play Too" are typical ones. This is where the pictures take on their names. Past that point it's how I think of them, so it's important to choose carefully. Once the name is chosen, I'll jot that down in my notebook beside that frame number or that collection of frame numbers.

From here on out things get a little more dicey. This is where the bulk of the changes in my workflow have happened, because this is where the nit pickey details of getting images ready for print really kick in. At this point we have images that have been assembled, if necessary, had optical distortions of the lens removed, if necessary, and have been cropped for composition and the choice of print medium. But the color of the individual pixels is still untouched.

In darkroom printing, this is the point when a paper is chosen, a developer is selected and mixed, and the test strips get made to check for proper choice of contrast filter, exposure time, development time, etc. In short this is when the final print medium is chosen, and when the picture is tuned for that medium.

In digital printing, the same is true. Since the end result in this case is a book printed at Blurb, that's the example I'll use. The first step is to have a calibrated system so you know what you're going to get on the printed page. I wound up getting a Spyder2Express, which is a combination of a Spyder2 colorimeter and the Spyder2Express software for calibrating monitors. This is a very bare-bones calibration system, but it's all I need in order to calibrate my monitor for printing books at Blurb. More advanced systems allow you to calibrate projector systems, or develop ICC profiles for printers. Since I have the ICC profile for the printers, paper, and inks used on the printers Blurb uses, I really don't need anything that advanced.

One by one, the pictures are loaded into Photoshop on the calibrated system. With the Blurb ICC profile installed, I can preview what the picture will look like in print. Levels and curves are used at this point to render the picture the way I want it to appear in print. Previewing is an important step because it can show you where shadows are starting to block up, where highlights are getting blasted out with details lost, and where individual patches of color are falling outside the gamut of what the printer can reproduce. This is similar to the exposure strips that are done on an enlarger to check exposure time, development time, etc.

During this process, if shadow areas are starting to block up, but the overall exposure level of the image is still too light, selective dodging can be done to bring up the shadow areas so they don't lose detail. Likewise if highlights are starting to blow out, those areas can be selectively burned in to preserve detail. And if there are certain features in the image that need to be emphasized, selective dodging and burning can be done to emphasize those areas of the image.

When doing this I try to make all the changes using layers in Photoshop. This lets me go back later and tweak any individual effect, similar to how test prints and dodge and burn guides are done on an enlarger. I don't really like the Photoshop dodge and burn tool so I will typically do this by selecting an area with the lasso tool or with the magic wand tool, feather the selection, and apply that selection as a layer mask on an adjustment layer. Rather than sliding the black and white points, I typically make changes by sliding the gamma point around. The changes are small, rarely more than 0.15 in either direction. Too much and the effect is obvious, and gross. Subtle is better in this case.

Constant checks with the print preview and gamut overrun using the ICC profile from Blurb makes sure I'm keeping everything in the range of what the printer can handle, and that I'm preserving detail in shadows and highlights.

This is also when color correction is done. "Blue snow" is a common case when a camera's auto white balance can be fooled into making a strange color in an image. Large patches of snow in a wintery scene can result in the snow taking on a blue cast from reflected sky. The Photoshop Color Variations tool can be used like the color correction wheels on a color enlarger to dial in the colors and remove effects like blue snow.

Eventually a usable image is produced. The image is saved as a multi-layer Photoshop file, and then as a flattened JPG file. Blurb, as with most printers, expect a JPG or TIF file in the sRGB color space. They won't take 16-bit files, or multilayer Photoshop files, or RAW, or any of a whole host of formats we take for granted during processing. Keep it simple. But save your working file in case things don't work out the way you expect!

The last step is to send things off to the printer and see how well you did. Even the best monitor calibration and ICC profile is no match for seeing the final image in print. That's when you get to find out just how well you did.

Submissions for the WWKW 2009 book open in three days. This new workflow is just starting to become routine for me. By the time I've gone through the hundreds of images submitted for WWKW 2009, I expect it will be second-nature.

Tom

WWKW 2009 - And Counting

2009-04-17T23:41:00.001-07:00

So there are six days 'till WWKW 2009, and I just noticed my shutter servo tab has cracked, and my rig is inoperable.

AAAAAARGH!

I'm glad I saw it, though. Nothing worse than to have gear fail in the air and not know it. The way it happened was this:

One of my leg brackets wound up getting bent about a week ago, resulting in a crack almost completely through the bracket. Rather than risk failure, I ordered a new pair of leg brackets from Brooxes.com along with a folding Picavet.

The folding Picavet really is a thing of beauty. It comes in two pieces, and replaces the stock single-piece Picavet. By pulling a quick pin, you can rotate the top half of the Picavet, which can then be rotated parallel to the rig for some really compact packing. Even better, in the packed position there's a second hole to insert the quick pin so that it locks the Picavet in that position, too.

After installing the new Picavet, re-lacing my Picavet lines because I couldn't keep the pulleys straight, removing the broken leg bracket and my old antenna bracket, and installing the new leg bracket, I finally saw that my shutter servo was sitting at some oddball angle. Oh dear...

I toyed around with the idea of building a new bracket, and even bent up some of my 1/64" brass strip stock while testing out a couple of ideas. In the end I went back to trying to get the GentLED-CHDK2 working with my camera, a Canon Powershot A650IS. When I first got it I had no end of problems trying to get the A650 to recognize the timing coming out of the CHDK2. Things hadn't improved, and more testing only indicated the same behavior.

As a last ditch effort, I asked to see if I could exchange the CHDK2 for a GentLED-CHDK, which does work remarkably well with the A650IS. Hoping for a positive response.

If not, I've got enough Atmel ATtiny hardware lying around to make a fair simulacrum of a GentLED-CHDK, and can get that built before WWKW 2009. And failing that I'll sacrifice another shutter servo to my existing bracket, knowing full-well the mounting tab will likely crack off within the year.

I'm not giving up on my chances of doing massive KAP during WWKW 2009, but I hate having set-backs this late in the game. It makes me paranoid.

Tom

Plans for WWKW 2009

2009-04-08T16:05:00.000-07:00

World Wide KAP Week 2009 is two days away, slated to start Friday, 24 April, 2009, and extend through 5 May, 2009. My own planning started months ago when the dates were first announced, but as things are getting closer, plans that were once vague maybes are firming up into certainties.

Gear -

I've made a number of changes to my gear, and added some new things to the bag:

4x5 - Lots of changes since the last WWKW, but nothing new in months. All my film holders are loaded, so it's a matter of bringing it everywhere I go, and hoping for dead smooth wind. Maybe also bring some counterweights to try to damp down the remaining vibrations.

Archaeo - I've got a new rig this year that's all ready to go: my ortho-only archaeology rig. This is the rig I also plan to use for garden photography, so that may be where I use it during WWKW 2009.

RC Rig - I've changed out my radio to a 2.4GHz Turborix radio, and added a prototype for an AutoKAP controller that's now under development. Both will get field time this year. I'm also adding a folding Picavet to make packing my rig into my bag even easier.

Anemometer - I bought an anemometer from one of my print sales, so I can keep better track of the conditions in the field, and go back later to compare with the wind models.

Winder - My new winder is now a thoroughly tested and battle-scarred denizen of my KAP bag, and will be my primary winder for the duration.

Locations -

Kohala:

Pu`ukohola Heiau
Spencer Beach Park (New)
Kawaihae Canoe Club (New)
Archaeological Sites along the Kohala coast
Lapakahi Historical Monument (New)
Mahukona + Lighthouse (New)
Decay north of Mahukona Park (New)
Mo`okini Heiau
King Kamehameha's Birthplace
Wind Farm (New)
Lighthouse
Pololu Valley
Next valley over (New)
Kohala Architecture & Sugar Camps (New)

Kona:

Hapuna (New)
Beach 69
Petroglyphs at Puako (New from kite)
Anaeho`omalu Bay
King's Trail Petroglyphs at Anaeo`omalu Bay (New)
Scoria Abrader Quarries at Waikoloa
Waikoloa Beach Resorts (New)
Beach Without a Name
Wainanali`i Pond and Kiholo Bay
Kua Bay
Anchialine Ponds along Kona Coast (New)
Puako Tide Pools (New)
Pu`u Waawaa

Hamakua:

Waipi'o Valley
Akaka Falls (New)
Old trestles on the Hamakua Coast (New)
Gulch bridges on the Hamakua Coast (New)
Laupahoehoe Point (New)
Kalopa (New) (MAYBE)
Boiling Pots / Rainbow Falls (New)
One of the beach parks, but this is tough (New)

Waimea / Central:

Various sites in Waimea
Mana Road
Whistling Canyon (New)
Waimea Resevoirs (New)
Head of Waipi`o Valley (New)

Mauna Kea:

Mauna Kea Summit (New - Heiau has fallen over)
Lake Waiau (New)
Adze Quarry (New)
Cinder Cone Edge (New)
Domes & Dishes

Saddle Road:

Pu'u O'o Kipuka Trail (New)
Pu`u Huluhulu
Hunter's Cabin (New)
Silverswords on R14 (New)
Pu`u near Kilohana Check-In (New)

South Point:

South Point
Green Sand Beach (New)
Whittington Park
Across the bay from Place of Refuge (New)
Kealakekua Bay at Captain Cook's Monument (New)
HOVE - Road to the Sea, turn north (New)
Na`alehu (New)

Puna:

Kapoho Tide Pools (New)
Kalapana
Hike to Pu`u O`o ? (New)

Volcano NP - Contingent on permission from NP Director:

Ka`u Desert Trail; Footprints in Lava *
Chain of Craters Road Trail *
Great Rift? * (This may be hard to get to)

Goals -

I want to fly in new locations, most specifically on the south side of the island. There really is architecture down there, along with the Kapoho tide pools, sites inside and outside of Volcano, Green Sand Beach, and a couple of archaeological sites.

I'd like to fly some of the less-likely locations for Hawaii. I've done tons of beaches. I want to show off cattle country, desert country, volcano country, etc. There's more to Hawaii than beaches. Besides, this is a vitally important component of the book I'd like to do later in the year of low altitude aerials of Hawaii.

I want to take some 4x5 photos from the air. I'd really like at least one rock solid image I can print at wall mural size. If I can get a couple of solid ones, I'll be happy as can be.

Mostly I want to have fun, knowing that all over the world people will be flying cameras on kites anywhere and everywhere they are, and sharing what they see. I was blown away by the output for WWKW 2008. I can't wait to see what happens for WWKW 2009!

-- Tom

I Bought an Anemometer

2009-03-05T12:46:00.000-08:00

Not the most original title for a journal entry, but it's the truth. I did buy an anemometer: a Kestrel 2000. I can't say it was an impulse buy since I've been looking at anemometers a little over two years now. But the decision to get it right now? I suppose it was.

I've been holding off on getting an anemometer, probably for relatively silly reasons. I can gauge wind pretty well, and the wind models I use are generally accurate. But I've had a bad run of KAP outings recently when I would either find the wind too weak to lift a rig, or too strong to safely fly a kite. I've come home frustrated, more often than not, with little to show for it. An anemometer can't make the wind blow, but it can send a very clear message if the conditions just aren't right.

Another reason I decided to buy one now is that World Wide KAP Week 2009 is coming up soon, and given my finances, there's no way I'd be able to get the kite I've been lusting after (a Dan Leigh Trooper RS, a high-wind delta that can handle the conditions at Upolu Point and Southpoint.) So I took what finances I had and put them into the anemometer. It will be a useful addition to my KAP bag, and if it gives me better awareness of the flying conditions at a new site, it could make the difference between a successful outing and one that ends in damaged or destroyed gear. A sound investment.

But in a larger sense, it was just plain time. A few years ago, if asked which hobby was actually paying for itself the best, I would have to say machining and writing. I wrote a couple of articles for a machining magazine, and when they were published it was the first time I'd ever actually had a hobby start paying for itself. The funny thing is, I used the money from the articles to pay for KAP gear rather than tools. To be fair, I did use some of it to buy two years worth of subscriptions to my machining magazines, so it did go back into the hobby to some extent. But it also helped bootstrap the next.

Today a more truthful answer is that it's KAP that's bringing in the most real revenue. I've sold a number of prints, and have had requests for even larger prints though so far none of those requests have led to a sale. Nonetheless, my KAP hobby has done more to pay for itself than any other hobby I've got. By and large, about half my KAP gear was paid for by print sales. This is better than my ratio for my machine shop and those magazine articles, but it's still not a hundred percent.

I'm at a bit of a leaping-off point. Selling prints is great, but I don't really think that's where I'm going to stop in terms of letting KAP pay for itself. I'm looking at other options, most of which involve doing paying gigs. But for paying gigs to work out, there has to be some guarantee that the flight can happen, and that the right tools are used for the conditions. And for new kite purchases to make sense, I have to be able to demonstrate to myself that I've been asked to fly in conditions that would warrant them.

Hence the anemometer. WWKW 2009 is an excellent opportunity to characterize each of the kites I use, to find out the wind range for each one where I can reliably lift my KAP rig, and the line angle I'm likely to get. This information can be used to plan shots in ways I've never been able to do, and to provide a better guarantee that I can pull off a particular shot.

My goal, by the end of WWKW 2009, is to have a portfolio of images to show to prospective clients, and the ability to know if my gear can pull off a shot that a customer asks for. The anemometer is the first step in this direction.

There's an old adage that as soon as you start to do a hobby for money, it turns into a job. The point, of course, is to keep hobbies as hobbies and to keep work as work. But I'd be lying if I said I wasn't thrilled when I saw my first article printed in that magazine. It only made me want to write more. And when my first KAP print sold, I was ecstatic. I hope this next leg of the venture works out as well.

-- Tom

KAP Aerial Archaeology and Photosynth

2009-02-26T22:53:00.000-08:00

I've been frustrated in my attempts to turn KAP aerial archaeology shots into maps, or even into stitched panoramas that bear any real resemblance to reality. For the most part this is because I really don't have the right tools to get the job done. Photogrammetry, and georectification are not simple to do, and most consumer-level tools aren't suited to the job. Typically this involves software like Photomodeler, Leica Photogrammetry Suite, and GIS software. It also typically requires a grid of GPS-referenced ground control points. I'm not positioned to do any of these things.

But I did run across something that produced oddly pleasing results. It's a Microsoft R&D product called Photosynth. It's not so much stitching software (though I use Microsoft's Image Composite Editor for most of my stitching these days). Instead, Photosynth assumes the shots are not taken from the same vantage point, and finds all the points at which the shots overlap. This in turn is used to create a point cloud of intersection points between shots, so a viewer can place themselves at any of the vantage points from which the photos were taken, and see the scene from that point.

All of which is hard to say, but a lot easier to see. I tried this out using one of the flights from last weekend:

It worked remarkably well. Even more fun is to view it with the images turned off so you only see the point cloud of the intersection points between all the shots. Photosynth does a really good job of picking up the three-dimensional structure of the scene.

I tried it with some of my other KAP flights, just on a whim. The archaeology flights were almost all orthogonal to the ground, but most of the time when I'm out doing KAP I'm busy taking oblique shots rather than orthos. I was amazed at how well Photosynth dealt with this:

I think there's a lot of potential for what Photosynth is doing. There are all sorts of other features I'd ask for (and have asked for) beyond the existing Photosynth interface. Among others, it's ideally suited for picking out proper stereo pairs from a whole collection of images. It would be wonderful to have them all gathered, arranged, cropped, and ready to go.

Even better would be 3D model extraction from a random collection of photos of a scene. One KAP flighti n particular resulted in a really good point cloud for a large truck: a deuce-and-a-half. I'd love to be able to export that truck as a 3D model.

I don't know how much time I'll devote to this, but right now it's pretty fun. And for now walking around an archaeological site using my aerial still shots is as close as I can come to what i want: real 3D scene reconstruction.

-- Tom

More Archaeological KAP

2009-02-23T17:38:00.001-08:00

I got to do some more archaeological KAP last weekend. The archaeologist I worked with on Ahu A`Umi was on island a few weeks ago, and tried to fly his camera over the lava flows south of the resorts at Anaeho`omalu Bay. It used to be an active quarry for scoria, which in turn was made into abrader tools for working wood, bone, shell, etc. He wanted to see if the quarry and abrader workshops were visible from the air. Foul weather made for a disastrous KAP trip, so I offered to give it a try the next weekend. We traded some email planning out a strategy (wind direction, time of day, angle of light, etc.) and Saturday morning my son and I headed out.

The wind was certainly better than what he'd faced the previous weekend, but it was still turbulent, tossy, and a little too strong. With some reluctance I put up a Flowform 16 and 15' of fuzzy tail, and got down to business. The nature of lava makes it difficult to walk a consistent grid pattern, and I was reluctant to plant my big feet in anything of archaeological value that might be fragile. Nonetheless I spent about an hour and a half pacing around and chanting my mantra: "C'mon baby, steady wind steady wind. C'mon, don't no NOnono... ok, better, c'mon baby..." (I wonder if I'm the only KAPer who talks to his kites.)

At the end of that first session I took my son to a coffee shop at the nearby resort. He had milk and an apple turnover while I sipped coffee and reviewed my shots. As it turns out I'd used the wrong camera settings, and this combined with the turbulent wind resulted in over half the shots being too blurry to use. But there were enough sharp pictures to convince me to give it another try the next day.

The strangest part of the whole experience was that the entire time I was reviewing the pictures I'd taken, the sound system in the coffee shop was playing, Tex Ritter's "I Got Spurs That Jingle Jangle Jingle". I kid you not.

The next day the wind was much more laminar and of more reasonable speed. My son wasn't interested in going this time, so I took my daughter, who brought a book. This isn't unusual for her. What was unusual was that she only brought one. Normally a quick trip somewhere involves at least a small stack of books. "I never know what I want to read when I get there!" pretty much sums up her reason for this. I've quit asking.

The second day went much better than the first. I launched at a second site the archaeologist had marked out, and moved from there back to the original site I'd flown over the previous day. I found a better spot to fly from, and got a better grid the second go 'round. Toward the end of the session the wind was dying down, so I walked the rig back to my launch spot, where my daughter was still reading. I think she looked up maybe once the whole time. So much for getting out to fly kites with your kids. At least she guessed right on her book. It was what she wanted to read.

My daughter had heard of the coffee shop outing with my son the previous day, and was eager to get the same treat. So back we went, my daughter toting her book and me toting a camera with what I hoped were some better pictures than the day before. This time we both wound up getting chocolate croissants, which we munched while she read and I reviewed my pictures. What I saw put a smile on my face. Not only did the steady wind and the correct camera settings work out, the pictures very clearly showed quarry sites, abrader workshops, and even some petroglyphs I hadn't seen from the ground. Euphoria!

But as I continued to flip through the pictures it slowly dawned on me that the coffee shop was still playing, "I Got Spurs That Jingle Jangle Jingle". They didn't miss a beat.

Those two days generated about 3.5GB of data, probably 2GB of which is actually any good. I sent the disks off this morning in the hope they'll be there some time tomorrow. Meanwhile I've got "My Spurs Go Jingle Jangle Jingle" so firmly embedded in my head that even two hours of Linkin Park couldn't clear it out. I've given up. I fear that the very mention of scoria abrader quarries will forever summon up the jaunty notes of "I Got Spurs That Jingle Jangle Jingle":

I got spurs that jingle, jangle, jingle
As I go ridin' merrily along
And they sing, 'Away, too glad, you're single'
And that song ain't so very far from wrong

Oh Tex...

-- Tom

Root Cause Analysis

2009-01-04T13:35:00.000-08:00

In a previous career, I worked as a systems administrator for twelve years. When working with computer problems, one of the first things you need to learn to do is to see past the symptoms, and treat the underlying condition. It's something called "root cause analysis", and it's the backbone of computer troubleshooting.

In my present career, I do instrumentation at an international astronomical observatory. When diagnosing and maintaining scientific instrumentation, one of the first things you need to learn to do is see past the symptoms and treat the underlying condition. Root cause analysis again.

Recently, my KAP rig has suffered from an oddball problem: Each time I try to rotate the pan axis, there's a lag, and then it starts moving. The first time this happened in the field, I swapped batteries and went back into the air. When the symptoms didn't go away, I assumed both sets of batteries were low.

In a later flight I realized the small pinion in my pan axis gear reduction was loose. DOH! Without thinking about it, I tightened the screw that holds the pinion in place, and put it back in the air. Problem solved, right?

As it turns out, wrong.

About the third time I tightened that screw, I realized something else was wrong. I hadn't done proper root cause analysis; I'd just treated the symptoms of a loose screw. A little more poking around revealed the culprit: The pan axis itself was binding. This put additional torque on the pinion gear, which put extra force on the screw, which pulled it loose, which made the pan axis have backlash, which made for the lag when I tried to rotate it.

ARGH!

The cause of the tight pan axis was a bushing that was too tight in its hole. I made a new one with 0.005" clearance, and everything ran like a well-oiled clock. I also used thread lock compound on the pinion gear screw, so it shouldn't get loose as easily. For good measure I also used a synthetic grease on the two bushings on the pan axis, so hopefully this will be the last time I deal with this problem.

Which is the real benefit of root cause analysis: never having to see a problem come back.

Time to go fly a kite!

Tom

Let's Set The Record Straight

2008-12-30T19:43:00.000-08:00

I realize this post will probably offend, but it needs writing nonetheless.

Recently, in an online photography forum, I ran across a thread asking if Photoshopped images should be considered in a different class from non-Photoshopped images. To be fair, the person who originated the thread was asking if obviously manipulated images should be posted to a photography gallery. But as the thread evolved people began to ask and answer the broader question. It was some of those answers that were more than a little upsetting.

In any discussion such as this one, or when discussing film vs. digital (which came up in this thread), someone invariably invokes the name of Ansel Adams as the pinnacle of "traditional photography", and as a figurehead for nobility behind the camera. This thread was no different, and indeed his spirit was summoned. Repeatedly. And, if I might say, incorrectly.

Ansel Adams was a huge innovator in his own right, and championed many ideas that at the time were pooh-poohed as vulgar, shocking, useless, or otherwise unacceptable. A good case in point: When Adams started out, view cameras and box cameras were the only show in town. Adams gravited toward the view camera because of the motions it offered, but to the best of my knowledge he never shut out any form of camera or format for the negative. When Agfa began producing cameras to hold their 35mm movie film so people could use it to take still shots, Adams picked one up early on. Various people gave him a hard time about it, but he persisted and took some remarkable photographs using that "pedestrian" gear.

This was far from an isolated incident. It was a pattern throughout his career. He was one of the field testers for Polaroid's products, and was a personal friend of Edwin Land. He also tested Kodak's first color film products, though he admitted the strength of his work lay in black and white. And he was a big proponent of image manipulation.

I'll say that again just so people are clear: He was a big proponent of image manipulation. This is made abundantly clear in his numerous writings. In his book, "Examples - The Making of 40 Photographs" he goes so far as to show his initial contact print from his negatives, his test prints, and his final print along with the dodge and burn notes for several of his photographs. Contrast adjustment? Yes. Dodging and burning? Yes. Tonal range compression and expansion? YES. (And you thought HDR was new... nope.) If it could be done in the darkroom, it was fair game.

So what about digital vs. film? Unfortunately Adams didn't live long enough to see digital hit mainstream, but in the introduction to "The Camera" (I think... my copy went wandering when I loaned it out a few years ago) he clearly stated that he was excited by the prospect of digital cameras and digital photography. I don't think he ever referred to it as digital imagery as so many film proponents do. Digital photography.

So please, stop invoking the name of Adams unless you really want his opinion. He made it pretty clear over and over and over.

"I have been immensely pleased with many creative explorations I have seen; they are evidence of great imagination and the awareness of enduring qualities of art. I often observe that the more "far-out" any work appears at first, the more exciting and valid it may prove to be."

-- Ansel Adams - "Examples: The Making of 40 Photographs"

I began to write a response to the thread in the forum, but in the end I erased my reply and moved on. Enough passionate photographers for one day. One more wasn't going to change anyone's opinion or do any more to provide an answer to the original question. As a friend of mine put it, "Opinions are like assholes. Everyone's got one." I'm no different.

- Tom

Anti Bokeh

2008-12-17T13:07:00.000-08:00

Bokeh (derived from Japanese, a noun boke ぼけ, meaning "blurred or fuzzy") is a photographic term referring to the appearance of out-of-focus areas in an image produced by a camera lens using a shallow depth of field.^[1] Different lens bokeh produces different aesthetic qualities in out-of-focus backgrounds, which are often used to reduce distractions and emphasize the primary subject.

Wikipedia

Almost everyone who has put a camera in manual mode, or who has used a manual-only camera, has played with depth of field. A shallow depth of field produces the bokeh effect described above. A wide depth of field brings more of the frame into acceptable focus.

But there are limits to what you can do with an aperture ring. Close down too much, and diffraction at the aperture starts to work against you, blurring out the picture. So what do you do with a shot that has a lot of range to cover?

One solution is to use a large format camera with motions and take advantage of the Scheimpflug Principle. I won't go into the details here, but the upshot is that you can tilt your plane of best focus by tilting the lens or film holder. If, say, you're photographing a field of flowers stretching from your feet out to infinity, it would be impossible to bring the entire field into sharp focus using the aperture ring alone. But you could tilt your lens and shift your plane of best focus until it coincided with the field of flowers. The entire field would be in focus, but everything above it or below it would begin to go out of focus. This is partially the reason why photographers like Adams and Weston were able to get incredibly sharp sweeping landscape shots, and it's the reason why many landscape photographers continue to use large format cameras to this day. (Including me!)

But what if you need everything above and below that field of flowers to be in focus as well? You can still stop down, and broaden your depth of field somewhat above and below. But again, there are limits. Eventually diffraction begins to work against you, and you start to fuzz out the overall image. Where can you go from here?

Back in 2000, I ran across GRAFICA Obscura, a web site written by Paul Haeberli of SGI. It described a method of taking a stack of images shot at different focus distances, and selecting only the sharpest bits of each image in order to combine them into a single, sharpest image. Paul used an edge-finding filter to build his layer masks, a technique that worked, but not perfectly well. I made some attempts to use his technique, but I ran into a number of problems and no real successes.

Skip forward to 2008 when I swapped out my Nikon Coolpix 5600 camera for a Canon A650 IS. One of the reasons I chose the A650 was that it could run CHDK, a scripting language that can run on top of the Canon firmware in many of their compact cameras. I was interested in running CHDK for several reasons, one of which was a bracketing script that was far more flexible than the bracketing available in the Canon firmware. Among other things, it let you bracket your focus.

All of this would've put me in no better position than I was already in with Paul Haeberli's technique, but times change. At some point in those intervening years, Alan Hadley wrote a package called CombineZM that automates and improves on the technique Paul Haeberli described. The combination of CHDK's bracketing script and CombineZM's ability to stack the images yields a tool to get infinite depth of field out of a scene.

Anti-Bokeh

It's not for every photographer, and certainly not for every situation. But it's one more tool to add to the tool belt. And now that that tool is there, it's something to think on when heading out into the field.

Tom

The Photo Competition

2008-12-01T06:42:00.002-08:00

Last year I found out that one of the local galleries hosts an annual black and white photography competition. This year I decided to enter. It's been one of those "learning experiences" we're told to appreciate. Phrased a different way: it's been painful.

Rules for photo competitions always look straightforward until you actually try to submit something. This one has an up-front screening process to weed out what makes it into the gallery. "Unmounted prints or slides". They're actually pretty explicit on this part of the requirements, and even bother to mention that submitted materials will not be returned. Three 8.5x11 prints and $45 in submission fees later, and I'm in.

Why three? I wanted to include at least one aerial, at least one traditional landscape, and at least one macro. Besides, I figured they'd can at least two of my shots, leaving only one to be printed large, matted, framed, etc.

Lesson #1 - If you submit it, you may have to print it.

Yep, all three pictures made it through the screening. So how to prepare the gallery prints? 18x24 is the maximum size called out in the rules. But are these maximum linear dimensions, or is it a square inch kind of thing? I punted on this question this year by submitting images that cropped well to that ratio, but some of my more printable pictures have 2:1 or even 3:1 aspect ratios. If it's a linear dimension limit, a 3:1 print would come out at 8x24. Historically, for this photo competition, every square inch counts and the larger the prints typically the more favorable the judging. Printing 8x24 would put any 3:1 panoramas behind the larger, more traditional aspect ratio prints. In the end I wound up printing 17x24 for one, and 18x24 for the other two. I'll wait 'till next year to submit panoramas. Printing for the three photos came out to $60.

Lesson #2 - Framing takes time.

Our submissions were due early in October, and we were supposed to have word whether our shots made it in by November 1st. Only none of us heard until closer to November 16th. Framed prints were due on December 1st, so that only left two weeks to print, mat, and frame the shots. I called the local frame shop, and they said there was a two week lead time on framing. Since I didn't have prints in-hand, that meant I had to find another way to get the framing done. In the end I wound up using an online framing supplier and bought Nielsen metal frames and mats cut to size. The supplier wouldn't ship glass through the mail, so I got acrylic.

When the package arrived I got busy. It wasn't until I'd started on my second print that I realized they'd cut all three mats to 17x24. With one week to go and no time to get replacement mats, I called the local frame shop to see if I could get them to at least make mats on a same-day basis. Lucky for me they were happy to do so. But because so many other people were getting prints framed for this competition, they were running low on certain supplies, like acid free mat boards. I got 6 ply mats instead of 4 ply, but they look nice.

Lesson #3 - Humidity is a bear

By the time I got the other two prints framed another fact of life in Hawai`i was staring me in the face: humidity. When I worked at the frame shop in Pennsylvania, any time we were doing archival framing we hung the prints in the mat using what's called a "linen hinge". Two pieces of acid free linen tape held the print at the upper two corners, and the print was allowed to drape across the mat aperture. This worked great, and when done properly would last for a hundred years or more. I did the same thing with my prints. Only with the huge humidity changes we get here, the print had expanded and buckled against the mat.

Times have changed, and now there are archival methods of dry mounting prints to acid free backer board. Next time I'll dry mount the prints and avoid the humidity issue.

Lesson #4 - Acrylic is fun for science projects

I had reservations about using acrylic. We did occasionally use it on super-huge prints when I worked at the frame shop, but for everything else we used glass. Getting glass clean can be entertainment itself, but conscientious application of Windex with a lint-free wipe usually got the job done. Still, we kept pieces of black velvet around to use as lint collectors once the glass was clean. On a bad day, it could take ten minutes or more to get a piece of glass ready. I heard there's a frame shop in Boston that bought up the cleanroom equipment from a chip manufacturer that closed its doors. That is a brilliant idea. If I ever go into the framing business myself, I'll follow their lead. The additional cost in HEPA filters is worth it.

Acrylic is a whole 'nuther ball game. It collects static charge the way kittens collect "Awwwww!"s. As soon as it's clean, something wants to stick to it. The very act of wiping dust off charges it even more. No matter what you do, the stuff is dirty. It's a pain. I did finally get the acrylic mostly clean, but it's not what I'd call a spotless job. Next year? Glass.

Lesson #5 - You have to show up

The framed prints are due in the gallery Monday the 1st. I've known this for over a month. They've been sitting in my office at work, ready to go. I could've handed them in Friday last week, but didn't. I wanted one more chance to see them before saying goodbye.

I've been scheduled to work at our remote facility, starting Monday the 1st. I've known this for a week. But somehow the two ideas didn't connect. Not until 2:30am Monday morning, anyway. I went from sleepy to bolt-upright awake in less than a minute, and even broke out in a sweat along the way. I still hadn't made caption cards, I still hadn't printed out the pricing cards. And they were in my office, not at home and certainly not in the gallery. I wouldn't get back into town until the gallery had closed. DOH!

I spent the next two hours printing cards, re-hanging the other two prints that were now suffering from humidity shifts, loading them into my wife's trunk, and trying to come up with a way to ask her to take my prints to the gallery. Now I'm going to go to work at our remote facility on about four hours of sleep. Next year? I'll plan to be in town when the pictures are due.

Lesson #6 - I know I'd do it again

Despite all the pain and anguish, I'd do it again in a heartbeat. I just hope all three prints sell. After everything I went through, I don't want a single one coming home with me.

-- Tom

Where Do I Go From Here?

2008-11-18T18:38:00.000-08:00

Attaching the camera to the kite line is where things can get very very complicated, or very very simple, depending on what your requirements and expectations are. Please note the distinction between requirements and expectations. The two are usually quite different.

If you go through all of the KAP rig photographs on Flickr, you'll see there's a huge diversity in design from the very simple to the very complex. Depending on your requirements, most rigs fit somewhere in the middle.

Requirement #1 - I want to be able to take photographs from the air

This one is straightforward. Tie your camera's wrist strap to your kite line, start an intervalometer or set the self-timer, and let it fly. This is how some people have started, and when the kite line and the camera swing and the wind all play nicely together they have come back with some really good images. If you're after instant gratification with KAP, this route is tough to beat. But eventually most people who stick with KAP move beyond this.

Requirement #2 - I would like to know where the camera is pointing

This is where adding a suspension comes in. Through all the history of KAP, two suspensions have stood the test of time: the pendulum and the Picavet. That's not to say that other suspension methods can't work, and people continue to experiment. But if your aim is to get a camera airborne, experimenting before you have one flying is probably not the best bet. A pendulum is fairly straightforward: a rod that hangs down from the kite line with the camera attached to it. A Picavet suspension is a little more involved, but is also fairly easy to make or buy.

How you attach your camera to the suspension of your choice is where things start to get interesting. The simplest method is to attach the camera directly to it, either pointing horizontal (e.g. threading a pendulum or Picavet directly into your camera's tripod socket) or down (using a piece of angle).

Requirement #3 - I would like to point my camera some direction other than down or sideways.

At the very least, you'll need an extra pivot point that you can rotate your camera about. This can be very simple, such as using a slightly larger piece of angle and setting the tilt angle by rotating the camera before locking the tripod screw, or it can be more complex, such as building some sort of tilting frame.

Before going any further, it's worth mentioning that practically every aerial photograph can be taken with a rig that meets those three requirements. Fancy? No. User-friendly? Actually, yes. But does it let you make decisions on the fly as far as pan, tilt, or when to take your exposures? No. Still, not every KAP session needs that kind of flexibility. For a lot of KAP this is as far as you need to go. Past this point we're not discussing requirements so much as we're discussing expectations. You really can do excellent KAP with nothing more than we've already covered.

Expectation #1 - I want to be able to change where my camera is pointing on the fly.

This is where one of the major divisions in KAPing styles comes into play: RC-KAP vs. AutoKAP. Both involve adding motors to your rig. The easiest way to do this is to use off-the-shelf servos made for remote control aircraft. There are all manner of ways to incorporate these into a KAP rig design, ranging from direct drive to geared drive to push-arm, and everything in between. Rather than go through the list, take another look at the KAP rig photographs on Flickr.

Once your rig is motorized, you can either add an RC radio and do RC-KAP, or add a controller that will pivot and tilt your camera through a fixed set of orientations and do AutoKAP. Again, there are numerous options for accomplishing either of these.

Expectation #2 - I want to see what my camera sees before I trip the shutter.

We come, at the very last, to video feedback. It's odd how many people begin with this in their requirement list, and how few people doing KAP actually use it. The truth of the matter is that it is rarely cheap, it is rarely simple, and it adds a layer of complexity to doing KAP that is rarely needed.

That's not to say it doesn't have its place. If you are doing aerial photography as part of a portrait or model shoot, you don't have the option of getting your shots wrong. Likewise if you've been called in to do architectural photography and the customer has specified views they need to see in the images from the shoot, not having video feedback can be a huge gamble. But for the sake of going out and taking pictures of a place that's pretty, intriguing, and stands a good chance of being interesting from the air, it's hardly a requirement. Be sure you know what kind of KAP you plan on doing before insisting your rig has this capability. Chances are you don't need it, and the cost associated with it can easily be more than all your other KAP gear put together.

In closing, these are pictures of two of my three rigs at the moment:

The first is a two-axis rig that can either be run with an AutoKAP controller, or with an RC radio. In this shot it's configured with the radio. Most of the parts came from Brooxes in the form of a BBKK kit with a set of PeKaBe blocks on the Picavet, and a reduction gearbox on the pan axis. It's relatively heavy, it requires the operator to fly a kite while aiming a camera, and it's one of the more expensive ways to get into KAP.

The other is a down-only rig, using the same camera. It has no radio, no servos, no ability to control the camera in flight except by walking around or letting out more or less kite line. All of the parts except the camera and Picavet came out of my scrap box at home, and took less than an hour to assemble. It's relatively light, it puts no additional burden on the operator besides that of flying the kite, and except for the camera and Picavet, it was essentially free. With one slight change it could be made to let the camera tilt anywhere from straight down to horizontal.

Both produce good pictures from the air. Both meet requirements #1 and #2 above. The RC rig also meets requirement #3 as well as expectation #1. Neither meets expectation #2. These two rigs have produced 99.99% of my KAP photos.

As for where to start, only you can decide. Many people start simple. Some of them migrate to more complex rigs, but others don't. Other people start complex. Some of them migrate to simpler rigs, but others don't. It's an individual decision that only you can make. But in the end the objective is the same: Attach a camera to a kite line, and take pictures from the air.

-- Tom

What Camera Should I Buy?

2008-11-16T12:55:00.001-08:00

"What camera should I buy?"

This question is asked at some point in practically every photography-related forum. Usually the question is answered by a whole string of people whose responses take the form of:

"I use [insert camera model X] and LOVE it! You should get the same thing! You won't be disappointed!"

Unfortunately the plain fact of the matter is that you might very well be disappointed because their needs may not match your own, regardless of whether you're doing photography on the ground or from the air. There are no simple answers to this question. Ever.

With KAP, there are a number of considerations you might want to look at, depending on what you plan to do with your rig. A generously wide field of view is a common concern, as is the ability to trigger the shutter from an IR or electronic remote. Image quality and noise characteristics are another set of concerns that often go hand-in-hand. And of course there's the ever-present quest for more pixels without having to lose in any of these other areas.

But for KAP one of the overwhelming considerations is weight. This is not to say that light is always better than heavy, but no other characteristic of a camera will affect the rest of a person's KAP equipment more.

By way of example, there are two very successful KAP photographers who operate at two very different ends of this scale. One uses an ultra lightweight automatic rig. There is no radio transmitter, no receiver, only the camera, a servo for pan rotation, and a controller that will rotate the rig and take pictures. The rig is mostly flown from lightweight, high angle kites that let the rig be operated with a nearly slack line between the rig and the KAPer. This setup has produced numerous outstanding photos.

The other uses comparatively heavy medium format film gear. Because of the additional weight in the camera, it needs a substantially heavier rig to support it. The heavier rig and camera combination must then be hung from a kite capable of developing a great deal of pull. Larger kites cost more, so in addition to the more expensive camera hardware, the kite is also more expensive. Since this represents a large investment in airborne hardware, the safety factor in the line is higher, making for heavier line. In the case of this KAPer the line is also doubled so that in the event of a line failure there is a second line to take up the load. All of this adds to the cost. This setup has also produced numerous outstanding photos.

So which one is "right"?

And when Rabbit said, "Honey or condensed milk with your bread?" [Pooh] was so excited that he said, "Both," and then, so as not to seem greedy, he added, "but don't bother about the bread, please."
-- A.A. Milne, "Winne-The-Pooh"

There is no one right answer. Each is "right" for the photographer in question. Which more or less leaves someone interested in getting into KAP with no more information than they started with, which isn't entirely a fair thing to do.

Rather than leave things there, I'll share with you my own route into KAP. As for which camera I started with, I started with a camera I had on hand. In my own matrix of features versus trade-offs, it had the perfect combination: I already had it.

On the plus side, it wasn't that heavy. On the minus side, it had some oddball characteristics that didn't make it ideal for KAP. One of these was that it liked to turn itself off to save power, and there was no practical way to get rid of this problem. So I opted for an impractical way, and simply never stopped taking pictures the entire time the camera was in the air. I still lost a lot of shots because of this when the camera turned off mid-flight, but for the most part it worked.

My second KAP camera weighed twice as much, and increased my rig weight from 600g to 800g in one fell swoop. This impacted my ability to fly it. For starters, all of my kites needed more wind in order to lift the rig. But the wind range of the individual kites didn't change, so in essence this compressed their available wind range. For some kites, like my 6' rokkaku, it was hard to tell the difference. For others, like my Fled, it means I can't use that kite at all for this rig.

There are certainly lighter cameras available, but for what I wanted it was the right camera for the job. But the trade-off is that I have fewer opportunities to fly it. This can be addressed in several ways. One is to trade it in for a lighter camera. Another is to keep the heavier camera, but build a lighter rig. This is something I've done with this camera, and it wound up saving the day on a once-of-a-lifetime KAPing trip. Yet another way to address this is to get a new set of kites that will fly the heavier camera rig, and regain my wind range that way.

So even for a single KAPer, there may still not be a "right" way to go. It's a tough question that only you can answer for yourself. What camera is right for you? Only you can know.

Nonetheless, there are some things to look for in a KAP camera, though you won't necessarily get one camera that fits all of these:

Weight - I've already made the point that weight affects all other aspects of KAP. Unless you're ready to invest in larger kites, heavier line, etc. you might want to start light.
Field of View - Most of the time people look for wide angle cameras for use on kites. It's difficult to aim a camera with a narrow field of view, and tighter fields of view accentuate motion blur from rig swing. Wider, in this case, really is better most of the time.
Manual Settings - In addition to letting you choose your shutter speed and aperture, most cameras with manual settings also don't get to insistent about turning themselves off or putting themselves into some sort of power saving mode. It's worth checking both of these things.
Remote Triggering - Unless the camera has some provision for remote shutter release, the only way to get it to take a picture is to push the shutter button. This is not a show stopper, and all of my rigs but one use a servo as a "finger" to hit the button. But the ability to use an infrared or electronic release means one fewer piece of equipment to have to loft, and one more part of your rig that can't fall out of alignment.
Battery Life - Cameras with longer battery life are friendlier for KAP. If the camera burns a set of batteries in an hour, the only way to keep flying is to keep a lot of batteries on hand. Cameras that let you shut off the LCD, put the camera in a power saving mode that it can wake up from, or are otherwise stingy with batteries are a plus.

You've probably noticed I didn't discuss the one thing that most camera reviews go ga-ga over: how many pixels the camera supports. Depending on what you want to do with your images, this may not be a big deal. For posting on the web, cameras with more than 2MP detectors may not buy you much. But if you're planning to make big poster sized prints, higher resolution cameras are called for. If you're planning to make wall murals, digital cameras may not be the route to go. (Now you understand why that one KAPer uses medium format film gear!) This is a question only you can answer, and has very little to do with a camera's aptitude for doing KAP.

As for particular brands, you're in luck. I've used cameras and lenses that were made anywhere from the early 1900's all the way up to cameras that came off the line less than a year ago. There's a world of difference. In order for a camera maker to stay competitive, they really do have to turn out a top-notch product. Chances are, if you're familiar with the manufacturer's name, you can't go too far wrong. Every camera manufacturer does occasionally turn out a lemon, so it's worth checking the digital camera review sites. But as for which brand is the best? See the quote from Winne the Pooh up above. But don't bother about the bread.

-- Tom

"Go Fly a Kite!" or How to Get Started with KAP

2008-11-11T06:51:00.000-08:00

In the hopes that the previous two posts have piqued your interest in KAP, and you're itching to get going, the following posts should help you on your way. But it's not a straightforward task, and there's a fair bit of work involved in order to get there. Don't worry, though. Most of it's actually a lot of fun. In order to start doing kite aerial photography, the first thing you need to do, quite literally, is go fly a kite.

This is one area where KAP differs from most other forms of photography. I can't describe how many times I've been out doing photography on the ground, and the light just didn't work, the weather wasn't right, the subject wasn't what I thought it would be, etc. The least extreme of these have been a whole series of incidents that begin with "Stop the car! Stop the car!" The most extreme involved lugging two camera bags and two tripods up a cliffside trail in Zion National Park and almost having to choose between losing the gear or losing the me when I stumbled. It was anything but fun, and resulted in not one usable shot.

KAP, on the other hand, always begins and ends with flying a kite. Even if the light's not right, even if the scene just didn't work out, you still get to go out and fly a kite. Early on, the typical KAPer will only own one or two kites, so situations will arise where they don't have the right kite for the wind they've been given. But much of the time the way this plays out is that there's plenty of wind for the kite, just not enough for the kite to lift the camera. In which case the entire outing isn't wasted, it just means you spent your time flying a kite rather than taking pictures.

I could point out all sorts of reasons why this is a good thing: You get the opportunity to research the wind available at this spot. You get to decide if shooting here is worth buying or making a lighter or heavier wind kite to add to your stable of kites. You get to see if the wind direction available here gives you the access you want for your subject, or if you need to find a better spot to fly from. But the real reason is that flying kites really is fun, regardless of whether you have a camera on your kite line or not. For this and for so many other reasons, KAP begins, ends, and depends on a real enjoyment of flying kites.

But not any kite will do. It's an unfortunate truism that most of the kites sold these days are, aerodynamically speaking, disasters. It doesn't matter how cool a kite looks, or if it has wings that really flap (really!), or that it has your favorite anime character silk screened across the sail. Most of the time the kites that are designed with these features in mind will set aside other features, like stability, lift, durability, ease of assembly, etc. in order to achieve their artistic goals. What you are left with is a kite that looks great pinned to the wall, but one that will happily fall right out of the sky if used as a kite.

A good KAP kite requires a couple of things:

It needs to be able to fly - This should go without saying, but it also means that kites from practically any place but a dedicated kite shop or kite maker really won't fit the bill.
It needs to be stable in the air - This is where you start narrowing down the available designs. Not every design is a stable flyer. With KAP, your kite is your tripod in the sky, so you need to use stable kites.
It needs to be able to lift your camera - If the kite never develops enough line pull to lift your rig, you won't be able to use it to take pictures from the air.
It needs to not develop so much lift that it's hard to fly - Ideally you want your kite to be able to lift your rig, but not much more than that. I like about a 4:1 ratio, but I'm conservative. Some people prefer even less pull, closer to a 2:1 ratio of pull to weight. If your kite is pulling 10:1 or 20:1, it's like trying to hold a truck back with a rope and still do photography. It's not fun.

I'd like to be able to list kite designs suitable to KAP, but that would be folly. Old designs are re-discovered, shortcomings in existing designs get addressed, and new designs are invented all the time. Any such list would instantly be out of date. Your best bet is to look into what kites people are flying for KAP, to find out what conditions they're flying them in, and to work from there. For my own part, I currently use two Flowforms, one for high wind and one for medium wind, a 6' rokkaku for lighter wind, and a Fled for lighter wind still. But other people use delta kites, doperos, tritons, calomils, pilots, and a whole host of others. And even this list leaves out all the modifications people have made to their kites to make them more suitable to KAP. Do your research. It won't be time wasted.

Once you've chosen a kite, go fly it. Find out what its wind range is, how it likes to be launched, what it does when it gets too much wind, what it does when it gets too little. Does it like to over-fly zenith? If so, how does it recover? Does it have any tendency to turn to one side or the other in a gust? And how does it recover from that? There is an endless list of quesitons you can only answer by getting out with your kite and flying it.

But it shouldn't be an onerous task. After all, kites really are fun to fly. And if they're not, maybe KAP is the wrong choice for you.

-- Tom

KAP - What's the Point?

2008-11-07T12:14:00.001-08:00

Before launching into the hows the whys and the whatfors of doing kite aerial photography, or KAP, one question that should be laid to rest early is:

"What's the point of hanging a camera from a kite line?"

The answer to which is: "What's the point in putting a camera anywhere?" The answer to that question is, "To take a picture from a particular vantage point." It's no different with a kite.

Photography is photography whether you do it from a tripod, from a hand held camera, or from the air. The whole point is to capture an image that shows the world from the vantage point of the photographer's choosing, showing a view of the photographer's choosing, and portraying the fall of light, shadow, and color as the photographer chooses. What a kite specifically offers is a vantage point that would otherwise be unavailable.

Which raises the next question:

"Why not just use an airplane?"

Kite aerial photography and airplane aerial photography really fill two very different needs, and a photographer who can utilize both is very fortunate indeed. In the United States, FAA regulations require airplanes and helicopters to stay at least a thousand feet above the ground over populated areas. If the vantage point you're after is between a thousand feet and several tens of thousands of feet above the ground, the airplane is probably your best bet. But if you're after a vantage point somewhat lower than that, you're out of luck.

"Why not just use a tall pole?"

You can, and many do. But even poles have limits. I use two, a 16' and a 25' hand held pole. Some photographers use hand held poles considerably longer than mine, and there are commercially available photography masts that can reach 100' above the ground. If you're after a vantage point higher than that, once more you're out of luck.

Kite aerial photography fills a gap in the list of available vantage points. Between the top of the pole and the bottom of the airplane, it's practically the only game in town.

Another advantage to KAP is that of cost. These alternatives are not cheap, nor are they typically portable or convenient. A 100' mast needs to be mounted in a vehicle of some sort in order to insure stability. This is an operation costing several thousand dollars, and few if any amateur photographers would get that kind of modification done to their own car or truck. Likewise, few photographers own their own airplanes or helicopters or have the resources to hire one that will give them ideal shooting conditions, like removing windows or doors, etc. By way of comparison, the entire contents of my KAP bag cost less than a two hour helicopter flight, and a small fraction of what a 100' mast would cost, and there are altitudes available to my KAP equipment that aren't available using the alternative methods.

Finally, KAP is convenient. Except for framed kites, my gear all packs into a single bag that still leaves room for food and water. By car or by foot, I can take it anywhere I could pack an SLR camera bag and tripod. If I need to move a little farther over to get the shot, I don't have to worry about roads for my mast truck. If the light is making and I need to stay a little later I don't have to worry about fuel or rental fees on an airplane or helicopter. And if I'm out walking and see a neat subject for a shot, I don't have to plan for an airplane or try to figure out how to get a mast truck into position. I can simply get a kite up, clip the camera on, and be shooting in minutes.

So what are you waiting for?

-- Tom

The View Up Here

2008-11-06T12:40:00.001-08:00

For a long time I had a blog called The Tiny Machine Shop where I described some of the projects I did in the machine shops at work, and in my shop at home. But I found I spent more and more of my time out in the field doing photography, and so the blog was gradually taken over with photography posts rather than machining posts. In the end I wound up changing the name of the blog, if not its URL, to reflect this new direction.

Now we've come full circle, and I expect to be spending more time in the shop and a little less time in the field. Rather than confuse things by changing all the names back, I'm starting a new blog strictly for photography. More specifically, this blog is going to focus on aerial photography done with cameras hanging from kite strings.

I hope, through the months and the years, to convince you that this is not a crazy idea, it's not a wacky fad that will surely pass, and is actually a very valid, very safe form of photography.

What is photography, except a way of selecting a scene, choosing a vantage point, and recording an image to share with others? What is a vantage point, except a place to put a camera? Be it on the ground, on a tripod, in the hand, on a ladder, or even hanging from a kite, there's really no difference. It's a place to put the artist's eye so they can create the image that caught their fancy.

Since this is a new beginning of sorts, please bear with me as I describe the gear I use, the techniques required to use it, describe safe practices, and try to convince you to hang your camera from a kite. If you are coming here from my other blog, this may be old information. If you've been doing kite aerial photography yourself, it will certainly be old information. But if you're a first time reader, preferably with a bent for photography already, you might find something new. I hope you will read on.

-- Tom