How to deal with overexposed photos

This is an article that has been opublished in the new section of Juzaphoto server called JuzaPhoto Magazine. Juzas web is well known to many protographers as a great source of useful tutorials as well as a meeting point of people hwo gather in the discussion forum. In the new section of the forum called JuzaPhoto Magazine there is a new article on photography published every week. The articles are supplied by the forum users and it is worth checking regularly if you want to see the tricks the other photographers use. The link to JuzaPhoto Magazine is given here.

I do not aspire to be your tutor; I do not feel experienced enough to give you the best solution. There are many ways the “burned-out whites” issue can be treated and some of them are maybe better – I will be happy to hear them from you! Let me introduce you the technique that I am using in most cases.

Dealing with whites, or better to say dealing with overexposure is one of the major issues in digital photography. While the underexposure, i.e. the presence of completely black areas in the image is usually not a big deal and sometimes it is even desired in case of BW shots or pictures where we require strong contrast, the overexposure of the opposite side of the luminance spectra (white) deteriorates the quality of the image significantly. It spoils the photo because it causes the loss of detail and it also attracts most attention in the picture. The overexposure of the image usually happens when there is way too much contrast in the photographed scene – i.e. during the sunny day and especially vulnerable are the motifs where the white object is being captured on dark background (as is the example I will show in this article). The usual protection against burned-out whites is to set the exposure shift of the camera to negative values but sometimes there is simply too little time to do anything with the camera setting – it is certainly better to take technically poor picture that not to take it at all, especially when something extraordinary happens! The software available on today’s market really works marvels and you can still get very good results even if the photo looks horrible on your camera’s LCD!

The photo I will work on is from a series of “fighting Kittiwakes” taken in later afternoon of a June 2008 at Runde island in Norway – it was shortly after the longest day of the year so the sunlight was still very strong illuminating the cliff colony of this Gull species. There is always something happening at that place – Kittiwakes are leaving for the sea to get some catch, they are being attacked by Great Skuas when returning back or they fly out in a group mobbing the flying-by White-tailed Eagles. Often broils erupt amongst the Kittiwakes as they try to hijack the nesting ledge of the bird that left it unattended (see the relevant article here). Watching these fights is really a spectacle but a challenge at the very same time if you try to capture that event with your camera. Here we come to the worst-case scenario photography-wise as the white, sun-lit birds are being shot against very dark rocky background in the shade. Setting up the camera to manual mode with correct exposure for illuminated birds is a solution that fails when the bird flies into the shade of the rock and vice versa. Using of the aperture priority (Av) mode (setting up the aperture value; shutter speed is handled automatically by the camera) with the negative exposure shift (-1.33 in case of presented picture) appears to be the best solution for given scene but it does not always give the best results. The camera metering system averages the photographed scene to desired value but it is not sensitive to the ratio of dark and light areas in the picture – in other words one picture with large amount of whites can be exposed correctly while the next one in the series where dark tones prevail can be overexposed in white areas. Let’s have a look at such a photo – the image below shows how the out-of-the-camera JPG image looks like – there is a lot of contrast between the dark background and white bird. We can try to retrieve more detail from the background but we can as well leave it as it is as the main focus here are the fighting birds. Although the midtones are exposed correctly (wings), the head and neck of the lower bird is overexposed. The detail shows the “washed-out” white areas on the bird’s neck.

Lets see below what would happen if we only had JPG file available – simple underexposure (Image – Adjustment – Exposure…) of the image in PS (Photoshop) with the value set up to –0.60 darkens the whole image but the overexposed whites from the original image still lacks any detail. The image is thus rather dull, lacks the contrast and misses the detail.

Take-home lesson - Always shoot in RAW files! there is not much we can do with overexposed JPG images other than cloning in the structure from undamaged parts og the image - of course this can be very tricky if not impossible.

Here we come to the point of why it is so important to shoot into RAW image format – the files with minimally processed data provide much more possibilities for adjustment including the brightness and detail recovery. The following animation shows one of the common RAW – file converters (Photoshop Camera Raw) indicating the overexposed area highlighted by red color. The histogram is cut off at its right (white) end signalizing the lost of detail in whites. There are many parameters that you can work with here as well (as are Recovery, Brightness, Contrast) but I just skip these and only focus on exposure slider as this is part of every raw-converter. By shifting the exposure to –0.60 we see that the highlighted are disappeared telling us the detail in the lightest parts of the image have been recovered and the histogram shows that the white end of the spectra is now safely rendered in the photo

The image below shows the detail of the adjusted RAW image – we can now see the details in the whitest parts of the image and unlike in case of JPG file, the photo still retains enough contrast.

Since there is still too much contrast between the dark background and the birds we use the Shadows/Highlights filter of Photoshop (Image – Adjustment – Shadows/Highlights) to bring up more detail from the background while reducing the brightness of the birds. The Shadows/Highlights filter is very useful tool but it needs to be handled with care as it can easily create artifacts, halos around edges or affect the colors hue. By default the values are set too strong for shadows so we need to set it to lower values – here I set Amount (the strength of the effect) to 15%, Tonal Width (extent of the “blacks” that will be taken into calculation) to 30% and left the Radius at 30px – decreasing Radius to minimum can cause the loss of local contrast so I usually keep it at the default value. I set the Amount fog Highlights to 40% and Tonal Width to 30% to darken the whites to my liking. These are not by any means the best values – they will differ from image to image and it is especially a matter of personal taste.

Below is the detail of the critical area after the Shadows/Highlights filter has been applied to the photo. There is still a stripe of feathers on the neck that is brighter than the other feathers. It is up to everyone’s decision if this is to be kept in the image as it might reflect the real light conditions in the scene or if the brightness should be reduced.

If you decide to reduce the brightest part, the easiest technique is to use the “Burn tool” from the tool palette. Burn tool is useful for local darkening of the image. It is powerful tool but as everything in post-processing it requires careful handling – I set up the Exposure to very low value (4% in this case) and the Range to Highlight. Just a few strokes with the brush eliminate the bright areas sufficiently as seen on the image below.

This is basically everything as for the handling of the overexposed areas. At this stage I’m applying all other final adjustments to the image – usually color correction (if it has not been done in raw-convertor), saturation and curves correction.

There is one good trick I have learned when working with Shadows/Highlights filter - the local contrast enhancement. This is commonly done by using the Unsharp mask but whites are especially sensitive to use of Unsharp mask – too strong Unsharp mask washes away the details. To retrieve even more detail from the whites, I apply the Shadows/Highlights filter again and set the values in a way that the details/structure is enhanced – again the values shown here are not necessarily the best ones – they mainly depends on the resolution of the image but note that the Radius is set to lower value. Here I work with Layers and only apply the local contrast enhancement to those critical extents of white; it can create awful halos around edges – try it yourself!

Below is the animation showing the difference between the original out-of-the-camera JPG and adjusted RAW image.

Note:

In this presentation I use Photoshop CS5 Extended and the PS-built function Shadows/Highlights but there are other ways how you can achieve the same effect – you can create two layers from your RAW file - one with normal exposure and one underexposed to retrieve detail from brightest areas of the image. Careful blending of the two layers will have the same effect although it can be more labour-intensive.

Jiri Slama is an amateur wildlife photographer from Czech Republic, currently working as geoscientists at the University of Bergen, Norway. His passion is mostly bird photography – you can see his work at www.jirislama.com