The Crystal Palace: An Example of the Photo Retouching Process

12Oct17

In my previous job, I worked in a prepress digital service bureau producing digital photographs for various commercial clients. “Retouching” was a big part of the services offered by the company I worked for and I learned a lot from my boss, who was a self-taught master of Adobe Photoshop.

When most people think about “retouching,” they often envision the radical alteration of images or the creation of totally artificial images such as the Computer Generated Imagery (CGI) that has become a big part of the movies we see. In my reality, this wasn’t the case. Retouching digital images was a routine step in preparing them for publication, and much of this work was fairly subtle in nature.

Adjusting the color of photographed objects so that the printed output matched the actual product color was a big part of what we did. Learning how to make the best use of Photoshop’s various color adjustment controls was an important part of that learning process. The modification of selected parts of images was another, such as taking a photo of a speedboat and replacing one brand of outboard motor with another.

During this time, I also absorbed a sort of “philosophy” of retouching from my boss. Some of these ideas were:

-If you notice the retouching in the final output or it has drawn attention to itself, you’ve failed. If the viewer can spot obvious retouching mistakes, you’re “busted,” but there’s a subtler standard at work, too. The finished image has to make visual sense; the various elements cannot contradict each other. Much of what I’m seeing these days has been worked over so much that it just looks fake to me, and this is just as much of a failure.

-Don’t just rely on the rote memorization of step-by-step guides from YouTube, photography magazines or websites to solve retouching problems in Photoshop. This limits your thinking. Rather, learn to understand what the various tools in Photoshop do and how they work. Then, you can think of Photoshop as a toolbox and use whatever tool works best for a particular task. Sometimes, it’s not the obvious choice, nor the one that the magazines recommend.

-Work using methods that allow you to “undo” whatever you have done. It’s very often the case that in working over an image, you end up in a situation where you didn’t quite get what you wanted (but learned a few things in the process). If you can get back to your last, best version of the work, you can proceed again with this new knowledge and produce a better result on the second try.

-Don’t try to solve all the problems in an image in one fell swoop. In my work, there is almost never one global “move” that will fix all aspects of an image. Solve the problems one-by-one, saving your changes as you go, and eventually everything will be finished.

With these guidelines in mind, I’d like to walk you through an example of how I retouched one particular image. It’s not a “how-to” guide or a Photoshop training manual, but more of a look at the problem-solving process.

Here at Saint John’s University we are celebrating the grand opening of the new Saint John’s Bible gallery in the newly-renovated Alcuin Library. I was asked to produce some photos of the facility before it opened to the public.

This state-of-the-art facility features seven large upright glass cases holding pages from the Bible. Any sort of photography in a room with 28 vertical glass surfaces is going to be challenging. In taking pictures of the display cases at HMML, I’m always having to watch out for the reflection of the camera and tripod appearing in the glass. Shots have to made at an angle to the glass; being directly in front of a glass case would mean ending up in the picture.

The glass used for the Bible gallery cases is a bit different. They are constructed with a special museum-grade glass of very low reflectivity—the effect is of near-invisibility. This allowed me far greater freedom to position the camera where I pleased rather than simply choosing points of view to avoid my own reflection.

Good as this glass is, it still shows reflections from light sources, and one such source turned out to be the thing that caused me the most trouble. It was a bright green (ugly) “EXIT” sign that, unfortunately, I couldn’t turn off for the photo session.

Unretouched 600px

Unretouched Photo of Bible gallery space. Not too bad, but oh, that green exit sign!

In the unretouched photo you can clearly see the sign itself, but you might overlook the six reflections of the word “EXIT” that appear in various places (twice in the center display case). There is also a problem with the base of the display case directly in line with the exit sign and the polished floor section in front of it; these picked up a nasty green color cast from the sign.

Unretouched with notation 600px

Problem areas circled in red. The green exit sign creates multiple reflections of the word “EXIT” as well as creating green color casts on the display case base and floor in front of it.

One rule I have for retouching is that the finished image has to make visual sense or else the viewer will know that something is wrong even if they can’t quite figure out what it is. This means that simply erasing the exit sign wouldn’t do—all the effects that the green sign has on the image must also be corrected.

The first step I take in retouching an image (if I know there will be substantial work) is to save it as a workfile in Photoshop’s “PSD” format. Here, for example, is the filename of the TIFF image I started with:

IMG_1484.tif

This is “saved as” with this name:

IMG_1484_WF.psd

In this way, the original file is not worked on and can be revisited in the future if it becomes necessary to completely start over with the work. The “WF” text in the filename instantly indicates to me that this is a workfile as opposed to an “output” file.

The next thing I do is select all of the content of the image (control+a) and float it to a new layer in the Photoshop file (control+j). This creates a new layer to work on with the original, untouched image below it. Now I have an instant backup of the original file within my workfile and can easily switch visibility between the layers so I can compare my work with the original. If things go astray, I can delete the layer I’m working on (by dragging it to the “trash can” icon in the layers tool palette) and start over if need be. As I work, I might select the “work layer” and float it to another new layer as I work in stages. This way, I can step back to my last good work layer if I mess something up with the next phase of work. This capability also allows me to try out techniques that I’m not really sure will work. If something fails, I can just delete the layer and go back down to the previous one.

This is merely one way of working with layers in Photoshop. If color and tonal corrections are the primary things being done, these corrections can be done in what are known as adjustment layers. These layers act like filters, imparting their effect on the image layer below without actually changing the image itself. They can be turned on or off and adjusted at will, providing great flexibility in creating variations on an image without having to create multiple images.

One of the problems with this image is that an overall color correction adjustment wasn’t going to fix everything; there are distinct areas with color problems, such as two small rectangular areas created by the reflective effects of the glass cases. These picked up an excessive green color from the exit sign. In order to work on just these areas without affecting the rest of the image a selection is created. This is a delineation of the area, made with any of a number of tools available, that isolates this area. This selection is then saved in the workfile as a separate alpha channel. In a complex workfile, there can by many such extra channels. By creating the selection, activating it, and performing some curve and saturation moves, the tone of this area was brought into line with the rest of the image.

selections 600px

Selected areas. These two rectangular areas of the photo picked up more green from the exit sign than others. A selection was created in these areas; working in “quick mask” mode shows the area that will be affected by any color-correction adjustments. As can be seen from the mask, only these two small areas will be affected.

Cloning out the “EXIT” reflections from the cases on the right side of the image was pretty straightforward. The double reflection in the center case was a bit tougher, as it sits in an area of tonal gradation. Anyone who uses Photoshop’s “rubber stamp” (cloning) tool knows that gradations are where cloning errors can stand out. In this case, there wasn’t a whole lot of source area to clone from that would create a seamless gradation. Even worse, the area is quite light in tone, and I’ve found that retouch errors in highlights are easier to spot than ones in shadow.

double exit reflections in case 600px.

Double reflection of “EXIT” in glass case. This would be tough to remove using only the “rubber stamp” tool.

The solution is theft. The tonal gradation caused by the overhead light in this area is fairly symmetrical, so I selected a portion of the right-hand side (it’s mirror image), floated it to a new layer, flipped it horizontally, and morphed it over the double reflection. Now with minimal touch-up, the double reflection was gone.

area to steal 600px

Image theft. By taking a portion of the image from the right side of the case and flipping it horizontally, it can be moved over to cover the reflections.

This worked well enough to make me think that the solution to the remaining green-contaminated areas could be to create a copy of the image, flip the entire thing right-to-left, and then use this uncontaminated “mirror image” material to replace the green stuff. This isn’t that hard to do, but remember that it’s easier to break up a problem into smaller parts and work on them individually.

With this in mind, I selected portions of the flipped image and created additional layers for the three problem areas: the exit sign itself, the green base of the display case, and the green area on the floor. This way I could custom-fit each replacement layer to its corresponding problem area beneath rather than trying to make the whole thing fit perfectly, which would have been a lucky feat if it had been done.

Original flipped 600px

Image flipped horizontally. Now, we can use image information from the left side of this flipped image that doesn’t have the nasty green problems. We can selectively reveal these sections to correct to original.

Next, it was a matter of employing layer masking, a powerful tool that many Photoshop users tend to overlook. Here’s how it works.

Taking the green base of the display case as an example, I worked in the layer above containing the corresponding area of the flipped image. Using Photoshop’s transform tools, I nudged and stretched the “replacement base” to fit the green base. Having the layer visibility set to 50%, I could see through the replacement layer to the green layer below, allowing me to line things up. Then, I set the visibility to 100%, and the green base disappeared.

But the work is not done, as the mirror-image selection was larger than the area I needed to replace. This is where layer masking comes in. By adding a layer mask and choosing “hide all,” the corrected layer suddenly disappeared again revealing the ugly green base of the case.

Now, using the brush tool, I could “paint in” the desired area from the hidden layer above. By toggling the “x” key, one can either “open up” the layer mask, showing more of the corrected layer above or “close up” parts of it to make fine corrections. Eventually, an opening in the layer mask is created that allows just what is needed of the corrected layer above to cover up the green stuff below.

layer palette

Layers palette in Photoshop. The overall flipped image was harvested to create three separate work layers that could be morphed onto the problem areas on the left side of the original image.

This was then done with the other two problem areas, eliminating the exit sign altogether and getting the garish green spot off the floor. By working on each area separately, I could solve the puzzle piece by piece.

After that, I did couple of light dodging operations on the Bible pages to make them “pop” a bit and made a few subtle tonal correction. At this point the workfile is complete.

But I never send out workfiles to printers, web developers, or the communications folks where I work. There’s too much confusing stuff in the workfile: layers, alpha channels, paths (if they were created) and adjustment layers if they were employed. At best, this array of stuff is confusing and adds unnecessary file weight. At worse, it can cause output problems when the image goes through the imposition process to create printing plates.

So an output file is created. First, make sure all the layers needed to create the corrected image are “turned on.” Then flatten the layers, getting rid of any layers that were hidden. Next, discard any alpha channels and paths that were created in the retouch process. Now you can crop the image and resize it for its intended use. Finally, apply whatever level of sharpening you want. I never sharpen workfiles unless I create an extra new image layer simply for testing. Sharpening is something that is output-size-dependent, so it needs to be done after the image is properly sized for use. This also means that different versions of the image might need different cropping, sizing and sharpening, and that’s why the workfile is so important—it’s the source of all future image derivatives.

The output file is given a name such as:

IMG_1484_OP-sRGB.tif

In this case, we can see that it’s an output file (“WF” becomes “OP”) and that it has been saved in the sRGB colorspace as a TIFF format image file. It could also have been saved in CMYK for lithographic printing purposes or  in JPEG format for Powerpoint or the web. As long as you keep the workfile, you can create any version you need.

IMG_1484_Op-sRGB 600px

Final output image. Looks like nothing was done to it.

As it stands, the final image is a good example of something that underwent a fair bit of retouch, but doesn’t look like it, which is the whole point. It worked out fairly well, but I’m thinking of making my own temporary cover for those blasted green exit signs. It would be a lot less work.

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