P is not for Photoshop. It’s for post-processing. For many of you the two will seem to be the same thing. In the same way that we ‘google’ something to do a search on it, we talk about ‘photoshopping’ a photo when we are trying to manipulate it in some way. And when most people think of ‘photoshopping’, and so, by extension, post-processing, they think of something like the before and after images represented in the screenshot above. You’ll notice they are predominately portraits of female subjects too… photoshopping is often dictated by a magazines impression of what a subject should look like rather than what they do look like. Where did I get the screenshot? Well I ‘googled’ ‘photoshopping’, of course! Now if that isn’t a suitable way to bring this opening paragraph to a close, and to proceed to discuss the types of post-processing that aren’t ‘photoshopping’, I don’t know what is. So let’s get started, shall we?
Actually, before we begin, I want you to do me a favour. When I say post-processing, stop thinking ‘photoshopping’. Put the idea of making people thin, skin smooth and teeth white out of your head. Because for the majority of us, our photographs don’t require any of that. That’s not to say our subjects are always super models, but it is to say that our photography is best left as honest rather than manufactured – the before is more than likely what we want to capture than the after. Even so, the majority of our photographs do require – in fact, in some cases they beg for – some basic post-processing. And while the ideal is always to get the best shot you can in the camera, the better shot is almost always that near-perfect straight-out-of-camera (SOOC) image, pushed through a little bit of post-processing, usually on a computer using some software. But the software can be free, the post-processing can be quick, and the results can be impressive. And if, shock horror, the image SOOC isn’t near-perfect to begin with, the post-processing can (and I’ll be shot for admitting this in some quarters of the photography community) rescue an image. So it’s a worthwhile investment of your time as a newbie to photography (or even as an intermediate photographer) to learn a few things about it.
Rather than run through every menu item of every piece of commercially and freely available software out there – which, let’s face it, would be both impractical and downright boring – I’m going to focus on some typical post-processing adjustments that I use on a frequent basis – these are the type you typically need to make to your SOOC images even if they are almost perfect – and at the very end is a short list (and it’s only a list – research of the software is left as an exercise for the reader) of some tools that help to do this type of post-processing.
Typical adjustments I make
Digital images straight out of the camera are typically lacking in contrast. For want of a better term we often describe them as looking a bit flat. They have no oomph to them, and this is due to the fact that cameras have limited dynamic range – how much light they can distinguish between dark and bright, and it seems as if for fear of blowing highlights (making bright things pure white) or shadows (making dark things pure dark) cameras do their utmost to try to retain detail at either end of the histogram. The result is that the images the cameras produce are typically not availing of the full dynamic range of the sensor and so not reflective of the contrast of the scene that was captured. If there is just one post-processing step you are going to try, then, a boost of the contrast (for 99% of images, at least) is it.
Here’s a (boring) straight out of camera shot, on the left and a contrast-adjusted shot on the right,to give you a visual feel for what I mean:
There are a number of ways to boost contrast, and the technique you use depends on the software available to you. The simplest is to do exactly what you’d think – adjust the contrast via a contrast control. Usually there’s some sort of a slider you can adjust left (for less contrast) or right (for more contrast). You typically want to move this right – not too much, perhaps 10%.
More advanced techniques involve making a levels adjustment (setting the white, black and often a mid-grey point based on the image), which essentially re-calibrates the levels of the rest of the pixels in the shot to fall within these bounds. In the example above you might set the black point to be the darkest part of the lid and the white point to be the second L in Cully on the lid, for instance.
The most advanced technique is to do a curves adjustment, which is much like levels except that instead of linearly re-calibrating the pixels of the image it does so in a non-linear fashion according to a curve that you define. That’s all I’m going to say about that, given that it would warrant a blog post all of its own, and also is already covered in thousands of articles on thousands of websites.
One adjustment that even hobbyist photographers who’ve been snapping for years often forget to do is to correct the colours in the image. Why would you want to do this? Well without getting too much into the technical detail, what appears as white light isn’t always (or usually, in fact) white light and while our eyes are quite good at compensating for this, our cameras are not. They need to have a reference for white, and they pick one based on the white balance which may be set automatically or manually. Assuming the white balance is correct for a given source of light (e.g. tungsten light when indoors), something white photographed by your camera in that light will indeed reproduce as white (or at worst, as a neutral grey that can be adjusted to white via a levels adjustment). However something in the frame that is being primarily lit from a different light source may appear blue or orange or green. And if that thing is the actual subject of your photo (or indeed if your white balance is simply wrong for the scene in the first place) you’ll need to compensate.
Here’s an example. The photo on the left was is lit by diffused cloud outdoors, but shows what happens when the camera’s white balance is inadvertently set to tungsten (as might happen if you move from indoors to outdoors and are taking manual control of your white balance but forget to adjust it as you move). The photo on the right is the same shot colour corrected to match the daylight in which it was taken.
How do you do this? Well for this level of adjustment you need to be shooting in RAW format – it allows such an adjustment to be made without affecting the integrity of the image – but even if you shoot in JPEG you’ll be able to compensate for accidents (or difficult lighting) via a colour balance or white balance adjustment. The more advanced the software, the more likely you are to be able to make the change without affecting image quality. Note that the example shown is an exaggerated case, but it’s worth seeing the extreme to know to look out for the more realistic case, such as the difference shown below:
The main thing to look out for is an unnatural skin tone, which in this case are most likely caused by all the green in the image throwing the camera’s “brain” into compensating in the other direction with too much magenta.
Typically a fix uses an eye-dropper tool to pick out something that is a neutral grey (or white or black) in the image, and it shifts the colour balance accordingly, so that the object you select is made white, grey or black. In the photo above, knowing Síofra’s dress had a white background, I could place the dropper on the neck of the dress and get good results.
The next set of adjustments worth considering are related to composition – the first is a crude way of improving the composition of an image, or in some cases a way to get closer to the action by, effectively, digitally zooming in. The second can, as in my case, compensate for your inability to take photographs with straight horizons, and is especially important for landscapes and seascapes.
Again a visual example, this time of an image I feel was made stronger by a little bit of cropping:
You can see from the highlighted section of the original that I cropped in a little to remove the bed post and a lamp, and I did so without altering the aspect ratio of the original scene. I felt those elements were distracting and added nothing to the scene, while their exclusion strengthened the composition and made for a better image.
An example of straightening is below. By default I seem to take shots that are about 1.6 degrees off level, so I find the need to do this a lot. One leg must be shorter than the other or something!
The final type of adjustment to consider as part of your post-processing flow is a tweak to exposure. This is different to the contrast adjustment in that it is really about brightening or darkening the image, and it typically arises where your camera’s meter got it wrong – for dark or bright subjects, for instance, which the camera will (unless told otherwise) expose too bright or too dark. It’s best to get this right in camera, of course, especially if you shoot in JPEG mode, but if you don’t, you’re gonna want to find the brightness or exposure slider, or perhaps the levels adjustment used (in a different way) for contrast adjustments.
Here’s an example where the SOOC image is over-exposed and post-processing fixes the problem:
There are other adjustments you can make of course, but these four are the ones I find I use most often. Ideally I wouldn’t use anything other than, perhaps, contrast adjustments, but I’m only human and my camera’s only a camera.
That list of software…
Listed in order of price from the cheapest to the most expensive. Happy googling!
- Microsoft Office Picture Manager (included with Microsoft Office up to 2010)
- Windows Photo Gallery (included with Microsoft Windows Essentials since 2007)
- Picasa (a free download, created by Google)
- Gimp (a free open-source editor)
- iPhoto (part of iLife for Apple Mac users)
- Photoshop Elements (a cut price, but very capable version of Photoshop)
- Aperture (RAW editing for Mac users only)
- Lightroom (RAW editing for Windows and Mac users)
- Photoshop (the whole shebang… but at a significant cost. If you’re learning something from this series, you don’t need Photoshop, so spend your money on other things instead!).
There’s nothing worse than seeing a decent image that isn’t as strong as it could be for lack of a few seconds of simple post-processing with some readily available and not-too-expensive piece of software, so if you don’t currently post-process your images, go and try some of these adjustments on one of the free software packages, and I promise you’ll never look back.
And if that wasn’t enough…
Are you sitting comfortably? Here’s a 2 hour (!) YouTube video of a lecture that’s relevant to this topic, and one that I came across just as the post was going live, so I thought I’d share it. It’s by photographer Tim Grey, is shared online by B&H Photo Video (the holy grail of camera shops, in New York) and while it relates to the use of Photoshop it covers the sorts of adjustments that you might want to think about making to your images (and some others that you’ll rarely want or need).