The importance of post-processing

One of the most frustrating realizations I had when I began photographing insects was the fact that photographs didn’t come out of the camera “ready-to-go”—i.e., they still needed to be processed to some degree to make them look good. Even worse, this required processing is to large degree subjective based on the taste of the individual photographer, and as such a “quick manual” describing the exact process in a way that beginners can understand doesn’t exist. Essentially, I didn’t know that when I decided to become an insect photographer, that I would also have to become proficient at photo processing. This frustrates me a lot less now because I’ve finally worked out a process for doing this that works for me and that I am comfortable with, and having done so I also realize that every photographer has to go through this process for themselves to make their photographs look the way they want them to look. That said, I wish I’d had access to some easy tutorials when I was trying to figure out the process that could have saved me some stumbling time before arriving at a process I liked. With that in mind, I thought I would share a quick overview of how I deal with post-processing in the hopes that somebody else mind find a useful tip or two here as they try to figure out their own process. This is not meant to be an exhaustive description of all the post-processing tools that I might use, but rather the typical adjustments that are needed for almost all of the photographs that I take. To illustrate the process, I use a rather basic shot of a cricket that I photographed last week in northeastern Missouri. You can click on each photo to access a larger and better see the issues discussed and resulting enhancements.

Straight from the camera (JPG converted from original RAW file).

The photo above is basically how the shot came out of the camera. These days I shoot only in RAW format, as this allows the maximum amount of data to be retained regardless of how many times the file is accessed. The image above is a JPG converted directly from the unaltered RAW file, and you can see that it looks rather flat and could benefit from levels and color adjustments as well as sharpening and some general “cleaning up” of sensor dust artifacts and debris on the subject. Since I use a Canon body, I have the Digital Photo Professional software that came with the camera, and I also have Photoshop Elements. For my purposes, I’ve found it most convenient to do certain enhancements directly to the RAW file in DPP, generate a TIFF format version of the file from the edited RAW file, and then do the final enhancements to the TIFF file. Since TIFF is also a “loss-less” format, I can then use the enhanced TIFF to generate JPGs of whatever size and resolution on an as-needed basis without worrying about data loss in the full-sized, fully enhanced version of the photo. I think this is preferable to shooting JPGs directly or generating them directly from the RAW file because JPGs are not loss-less files, and as a result every time a JPG is accessed or modified there is a loss of data. Sure, you can go back to the original RAW file and generate a new JPG, but any enhancements made after the first conversion will have to be repeated. Another advantage to making adjustments in DPP is that they are reversable—the original, unaltered RAW file can always be recovered without the need to create multiple backups representing different stages of enhancement.

After initial processing (JPG converted from edited RAW file).

So, what enhancements do I do in DPP? First I open the tool palette and adjust the white balance—in this case it was a full flash photo, so I select “Flash” from the drop-down menu. Then I select the RGB tab and adjust the upper and lower levels on the histogram. The general approach is to cut off data-lacking areas at either extreme, but there is also a lot of subjectivity in deciding what “looks right”. I then open the Stamp Tool (I find cloning adjustments easier and more effective in DPP than in PS) and clone out dust marks in the background (I know, I need to clean my sensor) and debris on the subject. On that last point, there are purists who will argue that this is an “unnatural” alteration. I take a much less conservative position on such alterations, since in my opinion the entire photograph itself is the result of interpretation—not just of the photographer, but of the equipment used and settings chosen. If debris on the subject is an important aspect of the subject’s natural history, then it should remain. However, in most cases, dirt flecks on the subject are not an important part of the story and provide an unnecessary detraction from the aesthetic appearance of the photo. If any cropping is necessary I prefer to do this also in DPP since this is reversible should I change my mind at some point in the future. The second photo above shows what the image looks like after this initial round of post-processing in DPP. At this point, the RAW file is ready to be converted to TIFF format for final post-processing in PS.

After additional processing in Photoshop (jpg converted from edited TIFF).

After additional processing in Photoshop (jpg converted from edited TIFF).

Because I’ve done much of the levels adjustment and cloned out any flaws in DPP, the original TIFF needs only minor adjustments. I generally like to start with “Autocorrect” and see what it does, as this function usually does a good job of toning down highlights and shadows and especially giving a more natural color to blue sky backgrounds such as in this photo. If I don’t like the result from Autocorrect, I hit Ctrl+Z and adjust levels and color manually until I like the result. I find that most photos still benefit from a little bit of brightening and increased contrast (usually ~10% each), and this often also serves to add a little color saturation that is generally sufficient but can sometimes be too much. If the latter occurs, it’s an easy matter to adjust the saturation back down a little bit. After the levels and color are fully adjusted the only thing left to do is apply unsharp mask to sharpen up the photo and bring out the detail—remember to zoom the image to 100% to get the best view of how the settings affect the appearance of the photo, as the settings that you will need depend greatly on the size of the image. Once these adjustments are made, I save a new version of the file (I like to append the file name with “_enh”). The third photo above represents the final enhanced version, and it is this file that I will use to generate JPGs of whatever size I need on an as-needed basis. The original TIFF can be retained if desired, but since an identical version can always be generated anew from the enhanced RAW file this is not essential.

The head slightly narrower than the pronotum and early spring occurrence of this large nymph make me think this is the northern woods cricket (Gryllus vernalis).

The head slightly narrower than the pronotum and early spring occurrence of this large nymph in northeastern Missouri make me think this is the northern wood cricket (Gryllus vernalis).

I hope you’ve found one or tips of use in this little tutorial, which I end with the above frontal portrait of the subject shown in the previous photos. Based on its all black color, the head slight narrower than the pronotum, and its early spring occurrence as a late-instar nymph in northern Missouri, I take this to be a northern wood cricket, Gryllus vernalis, but of course I am open to being corrected by somebody more knowledgeable about crickets than I.

Copyright © Ted C. MacRae 2014

About Ted C. MacRae

Ted C. MacRae is a research entomologist by vocation and beetle taxonomist by avocation. Areas of expertise in the latter include worldwide jewel beetles (Buprestidae) and North American longhorned beetles (Cerambycidae). More recent work has focused on North American tiger beetles (Cicindelidae) and their distribution, ecology, and conservation.
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4 Responses to The importance of post-processing

  1. kjmacleod says:

    Love that last picture – worth the processing effort!

  2. Katy says:

    Thanks! Inspiring, maybe I’ll finally get myself that macro lens I’ve been dreaming about…!

  3. GeoffBr says:

    Thank you for this! I’ve stumbled on to some of these previously through painful trial and error and seeing a more systematic perspective is much appreciated. One follow-up question: regarding the subjective nature of your changes, how do you evaluate how much editing is “too much”? I think most novices, like myself, tend to prefer heavier saturation and contrast than I see many experts favoring, but it’s never been clear to me why one is better or worse than the other… or how to choose the “correct” levels if I can’t believe my own lying eyes.

    • Good question, and that is where taste, artistic intent, and the technical realms intersect. My photography is largely intended to show realistic portraits of insects in their native environment, so whatever adjustments I make are done with the intent of mimicking what I saw in the field. As a result, my adjustments tend not to be very aggressive unless the exposure of the image has some flaw that I’m trying to minimize. I know with levels adjustments the histogram is the Bible (here is a very good tutorial on levels adjustment in Photoshop), and oftentimes once the levels are properly adjusted little if any adjustment of saturation and contrast is necessary. For the latter, however, if I do adjust I generally go “by eye”, using minimal adjustments based on what “looks right”. I hope my eyes aren’t lying as well.

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