In the previous post of this series I explained what happens in a digital camera – how a batch of photons is converted into a digital file. This post will cover how to use that file to create an image which can be displayed electronically or printed. This activity is called post-processing, because the initial processing of the image is done by software within the camera.
For wildlife photography, I believe the aim of post-processing is to produce a final image that replicates what you saw as closely as possible. And by “what you saw” I mean what you saw with your eyes through your binoculars, and not what the camera thinks you saw. Modern cameras are extremely capable, but their abilities are vastly inferior to those of the eye, especially the eye aided by precision optics. Occasionally the camera will manage to capture an image exactly the way you wanted it, but most of the time, especially in wildlife photography, the raw material produced by the camera will need some help.
The above images show the out-of-the-box version (Dusky Antbird 1) and the final version after post-processing (Dusky Antbird 2). Which would you prefer?
Post-Processing and “Truth”
The first thing to understand is that post-processing is not cheating. I mention this because if you visit photography sites on social media you will discover that there are a lot of people who think that “the camera doesn’t lie”; and that any alteration made to an image amounts to a form of deception.
I believe this stems from a confusion between “photoshopping” and post-processing. It is true that Photoshop can be used for deceptive purposes. Editing the groom and his family out of wedding photographs after a divorce is a more common practice than you might hope, and in principle not very different from the Soviet practice of airbrushing comrades out of a photo after they had been liquidated. But most wildlife photographers are not interested in deception. They simply want to produce the best possible image from the raw material that the camera provides.
For the first 150 years or so after the camera was invented, photographers had to process their own images. Great photographers such as Ansell Adams and Yousuf Karsh spent hours in the darkroom making adjustments to the exposure to produce the print they wanted. Amateur photographers either set up their own darkrooms or trusted labs to the produce their images.
During the 1960s colour film became the norm, but the equipment used to produce prints was large, expensive, and complicated to operate. Because they could no longer develop their own prints, amateur photographers were left out of the process, with all decisions being made by the algorithms that controlled the equipment. By the time the first digital cameras became available in the early 1990s, people had become accustomed to the idea that developing images was some sort of sacred art that the amateur should not mess with.
Fortunately in the digital era the control of processing is now back in your hands. If you are content to let the software in your camera make all the creative decisions for you, then you won’t need to do post-processing. If, however, you want to control the process, this article will give you some tips on how to use this power effectively.
I intend to discuss concepts rather than provide a detailed “how-to” because the methods and terminology will be specific to the software you use.
Software for Post-Processing
The options for post-processing include:
- Adobe Lightroom. Since its introduction in 2007 this has become the product most often used by professional and advanced amateur photographers. Unfortunately you can no longer buy it as a stand-alone product – you have to lock into Adobe’s overpriced subscription model.
Camera Manufacturers’ Proprietary Software. The major camera brands provide free software to their users. These products are often very good at post-processing, but they lack Lightroom’s ability to tag and track images.
Adobe Photoshop. This is the software to use if you really want to get into deception. If you want to show a Snowy Owl on a tropical beach Photoshop can do it. But for less evil uses it is a very complicated and user-unfriendly tool that lacks Lightroom’s ability to import, organize and export images.
Others. A number of lesser-known products are available. Most are free software; most are aimed at people who want to get images quickly up on social media rather than at people who want to produce great images.
Plug-ins. Various products are available that do specific post-processing tasks such as sharpening better than comprehensive programs like Lightroom. They are generally referred to as plug-ins because they can (sometimes) be incorporated directly into your main post-processing software.
The choice is up to you. As with many things in photography, if you commit to learning how to get the best out of your software you will be farther ahead than if you shift between multiple solutions searching for the perfect choice.
Before we start, there are a few key things to be aware of:
- You can’t fix focus. No amount of processing will make an out-of-focus image look good.
- Ditto for blown highlights. As noted in the first post in this series, with white subjects in bright sunlight you are better off underexposing and making the correction in post-processing.
- As I mentioned in the previous post, if your images are captured in RAW format you can experiment with as many adjustments as you want: none of the changes you make will damage or alter the original image file.
Post-Processing – An Illustrated Example
This image is of a Prairie Warbler that Paul Mackenzie and I found north of Kingston this year. The bird had been flitting around in the bright sunlight so I was set up for that shot, but suddenly it hopped down to a nearby branch. It was now close enough for a good image but the branch was in the shade. I snapped off a quick shot before it beetled off but not surprisingly the image was somewhat underexposed.
I would like to walk you through the post-processing of this image, discussing the concepts as we go.
Colour Space. After importing the image into Lightroom the first correction I made was to change the colour space. Colour space is essentially a mathematical model for describing colours. By default Lightroom renders your images in Adobe RGB colour space, regardless of how you have set up your camera. The of impact of this change is that the colours in the image become desaturated, so my first step is to change the colour space back to Nikon Standard.
Lens Correction. No camera lens is perfect. Every lens model incorporates design choices, and those choices result in predictable optical imperfections. The lens correction module reads which model of lens you are using from the image metadata, then accounts for known issues such as distortion and perspective correction by adjusting the image. Most of the time the change is subtle, but I like to make this correction a part of my routine so that I don’t forget it later on.
Initial Crop. Cropping is the method of removing unneeded parts of the image so you can zero in on the subject matter. For bird photography in particular this is often necessary because birds are routinely farther away than you want them to be. If you hand-hold your camera, as I do, cropping is also needed to account for the fact that you may not always be able to swing a heavy lens into position and centre it exactly on your quarry in the brief moment before it absconds. I like to do an initial crop at this stage so I can focus on making the adjustments to the key part of the image. In this case I was happy with the initial crop so I left it as is.
Tip. For wildlife I generally find that it’s a good idea to leave some extra space in front of the creature so that it looks like it has room to move. An image that is off-centre is also often more aesthetically pleasing. However if you want to post the image to EBird or iNaturalist a tight crop centred on the species is desirable.
Initial Exposure Adjustment. At this point I will take a first cut at adjusting the exposure. My aim is to get it approximately right prior to making further changes.
Tip. Exposure adjustment is usually done by moving a slider. Because the changes (assuming you are working on a RAW file) are non-destructive, I often move the slider around quite a bit just to see how it affects the image. This is not only true for exposure: with the other common adjustments (contrast, highlights, shadows, black and white balance etc) it’s useful to try making big changes with the slider as it shows you the range of possible adjustments.
Black/White Sliders. Because this image needed a fair amount of exposure adjustment, I found that after making the change the black markings on the face of the bird looked a bit washed out compared to how the bird actually looked in the field. So I made a small adjustment to the black slider to bring back a darker line. In principle I could have used the Contrast slider to achieve the same result but I find that if I use excess Contrast it gives the image a slightly fake look so I tend to stay away from that tool.
Final Exposure. Having made a few changes, I then fine-tuned the exposure. For reference the final exposure was 2.13 stops wider than the original. I like a slightly dark image; but see the last photo in this post for an alternative.
Sharpening. Digital images always come out of the camera with a bit of softness. You can pre-set extra sharpening in the camera, but since sharpening is another change that can look fake if overdone, I prefer to sharpen the image during post processing. Lightroom has a decent sharpening module, but this is an area where a purpose-built plug-in can provide better results. The final step in preparing this image was to send it through a sharpening module – in this case Topaz DeNoise AI. The change is barely visible at this size format but would provide a crisper look if I decided to print the image at large scale (8×10 or larger).
Post-processing software has several additional capabilities you should learn how to use, though I did not need to use them for this image.
Shadows. One of the advantages of the RAW format is that it gathers information on all areas of the image, even those in shadow which JPEG might ignore or gloss over. You can use the shadows slider to bring up the light in areas that are shadowed. This can lead to a fake look if overused, but a bit of shadow adjustment will often help in revealing parts of the subject that did not show well in the original form. I tried playing with the Shadow slider on this image but concluded that it didn’t add anything useful.
Highlights. The Highlights slider is the opposite of Shadows: it can be used to enhance or tone down the bright parts of the image. Again, I didn’t find that an adjustment helped with this image.
Spot Removal. Your camera sensor is a dust magnet. If despite all your efforts it has attracted any flecks of dust they will show up as spots on the image. These are usually only visible against a light background such as the sky. The Spot Removal function can help fix this issue. In this case any spots that are present are not visible so I did not need to perform spot removal.
Straightening. If your image includes a horizontal line (such as the horizon) it will look better if that line is truly horizontal in your final image. Your software will give you the ability to tweak the “horizontalness” appropriately. Again, a boon to those of us who hand-hold heavy lenses.
De-Noising. As I mentioned in the last installment, images captured at low light are prone to noise. This is caused by stray photons messing up the work of the sensor, and shows up as grainy areas and odd colour blotches in the image. De-noising is best handled by dedicated plug-ins. In my opinion the best option available at the moment is DeNoise AI by Topaz Labs.
Modules to Use with Care
Post-processing software also allows you to adjust the saturation and luminance of colours. This can sometimes be beneficial in fixing colours that were washed out, for example by bright tropical sunlight. But beware!: colour adjustments are the fastest way to generate a fake-looking, over-processed image. So use this function only if you need it, and use it judiciously. I would recommend you stay away from the global Saturation and Vibrance sliders. The sliders for individual colours are less likely to lead you down the road to perdition.
One Final Note
If I were going to print this image I would be happy with the final, sharpened copy. However if I wanted to share it on social media I would bump up the exposure a bit more. I find that brighter images look better on a monitor or a mobile device. The image below is the same as the final version but the exposure has been increased by an additional 0.6 stops.
Other topics in this series
Wildlife Photography Tips #1 – Exposure Compensation
Wildlife Photography Tips #2 – Shutter Speed
Wildlife Photography Tips #3 – Back-Button Focus
Wildlife Photography Tips #4 – Choosing an Image File Format
This article was also published in The Blue Bill, the Journal of the Kingston Field Naturalists, Volume 67 #3, September 2020.