You’re in the field, having scouted a new location to capture a view of the landscape. You release the shutter button, then wave the back of the camera to see what you’ve captured… the sky is blocked out and coming back to you. You have a dreaded case of blinking, but does it really matter?
What are Blinkies?
Winks aren’t really a “thing”, at least not in and of themselves. They are simply your camera’s way of showing you where you have overexposed highlights or their underexposed equivalent (lowlights?!); these are over/under exposure warnings or alerts.
The same thing exists in Lightroom where Adobe calls them shadow and highlight clipping; if you have blocked shadows, they are displayed in blue, with blocked highlights displayed in red.
If you have a 24-bit image, each pixel has an 8-bit value saved separately for red, green, and blue. Bit depth allows one of 256 different possible brightness levels to be recorded; blocked underexposure is zero (i.e. no light is registered) and overexposure is 256 (i.e. above the highest brightness level possible high).
The image below is a good example of overexposure and underexposure in the same image; this was shot at sunset where the setting sun is very bright in the scene (with red clipping warnings), while the foreground is deep in shadow (and therefore blue clipping warnings).
Why Adobe calls them clipped becomes clear when you look at the histogram which plots (in gray) the average combined RGB brightness of each pixel in the entire image; the peaks show the most common brightness values.
In this case, the large gray areas are represented by the peak at the left end of the histogram. There is only a small area of extreme brightness and this is mostly red. They are “clipped” because, if you could save them, they would extend beyond the left and right ends of the histogram.
Use turn signals
Winks are useful in Lightroom because they help direct your edits in post-production, but – and the use of the term clipping is useful here – in the shadows there is Nope recorded light, while in the highlights there is too much light to record. All of this means that you have no information about which pixels are clipped.
When you get to post-production, it’s too late to rectify the problem because you can’t take the shot again; all you can do is hide this.
Activating the turn signals in camera is much more useful because when you chimpanze you at least know if you have a problem and where it is. On Canon cameras, the turn signals are called “Highlight Alert”, while on Nikon it is the “Highlights” selection in “Playback Display Options”. As the name suggests, these actually show you cut highlights rather than shadows.
But what do the blinkies actually show you? Remember that your camera only stores a single layer or “image”, with individual red, green and blue pixels recorded based on the color filter array that sits above the sensors. Demosaicing (by your camera or Lightroom), takes this single image, separates the red, green, and pixels into three (partial) layers, and then interpolates the final image.
A JPEG preview, based on the profile of the image, is then created, which you see when looking at an image on the back of your camera. And it’s also what the camera uses to activate the blinks and display the histogram.
It all means what you see is not what you get; it works on a JPEG copy. The raw file will have a lot more leeway (just one reason why you should never shoot only JPEGs unless you have a good reason to).
Also remember that oversaturation can occur in any of the three red, green or blue channels (which may or may not be a problem, depending on your subject) and usually (depending on the manufacturer) only activates when two of the three layers are affected. And even then… it will depend on your photo profile!
If you go for something vivid that boosts saturation and brightness, the JPEG is more likely to cut out, even if the raw file is perfectly fine. Selecting a neutral profile will give you a much better idea of what it really looks like.
What are the solutions to Blinkies?
Using blinkies is great, but they don’t tell you how much latitude you have in your image. Or rather, how much dynamic range there is.
The image below is underexposed and when you look at the histogram it is clear that the right half is unused.
The obvious solution is to increase exposure by at least one stop, a technique known as “right exposure”. This has the added benefit of reducing noise in the image. However, this will not solve the general problem of insufficient dynamic range, a problem in the image above.
One option would be to use a camera with greater dynamic range, such as the Nikon D850 (14.8 stops). Another option is to artificially increase dynamic range by taking bracketed exposures and then merging them into a high dynamic range (HDR) image. Although these get a bad rap because of the garish, heavily oversaturated, and overly sharp stereotypes, they truly solve a problem when used sparingly.
Do Blinkies really matter?
However, there is another solution, which is to pay no attention to it. It’s pertinent to remember that photography was invented nearly 200 years ago, and the first image, View from the Window of Le Gras, had low dynamic range and extended flickers.
In short, overexposure and underexposure have been part of photography since the beginning and the masters learned not only to deal with the limitations of their medium, but also to incorporate it into their working practices. In fact, black-and-white images are almost expected to contain blocked shadows and reflections, even from proponents of the zone system such as Ansel Adams.
The mantra “expose for shadows and develop for highlights” is the original analog equivalent of “expose right”. Thus, although these photographers had to practice their profession within the framework of the technical constraints imposed on them, this was not considered as a limit to their capacities.
Of course, photographers have always tried to push the boundaries of what has and can be achieved, but the root of both shooting methods is the same: artistic vision.
That is, shoot with intent. Go out having already imagined the image you want to produce and shoot with that in mind. It’s not necessarily about capturing reality as your eyes see it here and now. For example, if you want to capture silhouettes of people, there is no need to take five sets of bracketed images to produce an HDR image which is then reduced to a low dynamic range photo.
Conversely, if you want a hyper-real panoramic cityscape, you might want a gimbal tripod to shoot overlapping HDRs. And then everything else. Understanding the dynamic range of your image and how you want to use it is key to getting a photo you can work with.
Knowing the dynamic range of the real-world scene in front of you, and the tools and techniques with which you can tame it, just might allow you to create whatever you’ve imagined.
Do Blinks Really Matter?