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
Monday, May 18, 2009
Sunday, May 17, 2009
Workflow
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
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
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