The concept of tonal range is fundamental to every image. But for many photographers, tonal range goes unnoticed and unconsidered.
As we progress on our particular paths, there can be times when even the most mindful of us take some things for granted. The simple elements are sometimes overlooked first, such as a sloppy tripod setup or misdialed camera settings. In the same vein, the essential technical concepts of photography go misunderstood, misinterpreted, or (even worse!) completely forgotten. This malady spans all levels of skill and afflicts both pros and hobbyists alike.
As an example, consider the most basic building block of any image: light. Every photographer knows that, without light, you can’t capture a photo. And many photographers are adept at using light to create different effects (silhouettes, halos, intense shadows, etc.).
But what about the different tones that light creates? Our photographs are displays of contrast between light and dark, but the distance between the two is virtually limitless. As photographers, we can use an understanding of tonal range – that is, the distance between light and dark tones – to improve our images, and that’s what I want to discuss with you today.
What is the tonal range of an image?
Tonal range refers to the measure of brightness in an image, from pure black to pure white. The distance between the different brightness levels in our photos determines the degree of contrast.
Take a look at this tonal scale:
We move from complete darkness on the left (blacks) to complete light (whites) on the right. This scale – with its division into blacks, shadows, midtones, highlights, and whites – is commonly used by photographers to discuss tonal regions within their images. Note that it applies to both color and black-and-white photographs (though when thinking about color photos, you’ll need to mentally separate the color hues from the underlying tones).
Now, let’s talk about each of these values and how they relate to your photography.
Highlights
For a long time, I thought of highlights as the brightest portions of an image. But that isn’t quite right! In truth, highlights are the areas of a photograph that consist of high luminance (brightness) values yet still contain discernible detail.
Here’s an example of highlight luminance values (the highlight areas are indicated with red arrows):
Notice that even though the indicated areas are bright, there is still some discernible texture and detail within the bright spots. If we were to increase the exposure of the shot, in camera or with post-processing, those highlight areas would become so bright that they would lose detail entirely, and they would move into a different tonal region:
Whites
If you increase the brightness of a photo to the extent that the highlights become blown out (where details are invisible), you have reached the “whites” portion of the tonal range.
Even if the whites region of your photo doesn’t appear white, it may be considered a total white area due to the lack of detail. The following is an example of whites in an image:
Depending on the photo, it may or may not be desirable to push the exposure to the point of white-out. We’ll talk more about this as we discuss the relevance of tonal range when constructing your images.
Midtones
Midtones are – you guessed it! – in the middle. In other words, all luminance values that are not dark or light are considered midtones. In this next image, much of the clouds, as well as the gray portions of the horse, fall into the midtone region:
Most of the time our camera will attempt to create an average midtone exposure if left to its own devices. This isn’t necessarily a bad thing, but if you’re not careful, you might end up with a flat, uninspiring shot. You see, while midtones help to ensure much information is contained in an image, a photograph consisting of only midtones lacks dynamics.
Shadows
Areas that appear as shadows are the direct opposite of highlights. Therefore, shadows are the areas of a photo that are dark but still retain a level of detail.
My horse photo includes a lot of tones in the shadow region, so let’s use it one more time:
These darker areas still possess information seen by the viewer. However, if we darken them to the point where that detail gets lost or “burnt out,” then they become a completely black luminance value:
Blacks
Any portion of a photograph that has zero luminance is considered to be black. Much like the complete white areas earlier, these points within our images don’t have to be utterly devoid of color to be regarded as pure black.
Let’s look at some shadows that are completely burnt out and retain no detail whatsoever:
Completely black areas are so dark that you can see nothing. They’re like a dark abyss within a photograph. This might sound like a problem, but as with pure white portions of a photo, having pure black areas within an image isn’t necessarily a bad thing! Let me explain:
What tonal range is ideal?
If you ever witness a conversation among a group of photographers about the best tonal range within a photograph, you’ll see that opinions are divided.
Some photographers feel that images should contain no areas of complete black or complete white. These folks believe that, for the best results, all portions of the photograph should present some level of detail for the viewer. Put another way, the best photos don’t have an extreme tonal range, from pure black to pure white; instead, the tonal range remains slightly compressed.
Other photographers, however, contend that it’s perfectly fine to burn or blow out some luminance values for the sake of contrast. Doing this means that the final shot will have areas of complete black and complete white, and that all the other luminance values fall somewhere between those two absolutes. Such photos have a very expansive tonal range.
While it’s true that it is often desirable to deliver the maximum amount of visual information to your audience, this is not always the case. There are times when a crushed and burnt-out shadow or a blown-out highlight is just what you need to bring a photograph home.
Use tonal range to improve your photos!
In my opinion, there is no such thing as a perfect tonal range that you can apply across every photo. Instead, it depends on the scenario, as well as your creative vision.
What’s important, however, is that you always remember the concept of tonal range as you shoot and process your images. It might seem like a simple idea, but it’s easy to overlook the importance of how different levels of brightness affect an image.
Here’s a quick rundown of the tonal regions within a photo:
- Highlights: Bright areas within a photo that still maintain detail
- Whites: Areas of extreme brightness where there is absolutely no information (detail) remaining
- Midtones: These are neither shadows nor highlights but rather a middle value of luminance
- Shadows: Darker areas of the image that still maintain detail
- Blacks: Completely burnt-out portions of a photo that contains absolutely no detail
Like most concepts in photography, it’s essential to have a full understanding of the tonal range within your photos. You should use this knowledge to strive for technical excellence – but you should also use it to know when to break the rules to fulfill your creative vision.
Now over to you:
How will you make use of tonal range in your images? Share with us your thoughts and images in the comments below!
