Understanding Tonal Range in Photography & Why It’s Essential For Creating Exceptional Photos
Tonal range is one of those fundamental basics of digital photography that is often overlooked or misunderstood… let’s face it… it’s not a sexy topic!
Whether you’re a hobbyist or pro, we are all guilty of skipping the basic building blocks of photography at some point. Light and it’s luminance values in particular.
Light is the most essential element for any image. Without it, it’s like shooting with the lens cap on. Master light, and you’ll be able to shape your subject to tell a story, add depth, increase interest, and make your friends, family, and clients say “WOW!”
Tonal range is an ingredient of light. If you wish to create exceptional photos, then understanding the tonal range will help you master light.
Table of Contents
What Is Tonal Range In Photography?
The tonal range in photography is the range of tones between the darkest and brightest areas of an image or the luminance.
The darkest area represents pure black, and the brightest is pure white. In-between includes the shadows, mid-tones, and highlights.
This tonal range can be visually seen with a black to white gradient. The transition from one side to the other is the tonal range. An image with a wide range of tones will have pure black and pure white elements in the image. A small or narrow range of tones will include a smaller range from shadows to highlights. In other words, no pure black or pure white.
The brightness levels within your photos also determine the extent of contrast.
If you capture an image with a small range of tones, the overall contrast will be flatter vs. a larger range. In post-processing, you can increase the range of tones to add more contrast by stretching the image to the outer edges… by adding pure black and pure white.
In photography, the tonal range is divided into 5 luminance (brightness) values; black, shadows, mid-tones, highlights, and whites. Let’s review each with a photo example.
Pure black in an image is a result of zero luminance. It’s void of any detail. However, an area doesn’t have to be void of texture to be considered pure black. Check out the image below.
The blue overlay mask represents pure black. The areas around it also appear to be void of detail due to the luminance value. However, those areas contain small amounts of texture too.
Pro Tip: Your histogram is a good source of finding detail in areas that appear to be pure black or pure white. With this knowledge, you can edit the image accordingly to make it visible.
Shadows consist of luminance values that are brighter than pure black. This lends these values to display the textures and details of that part of the image.
Sometimes, shadows can appear to be closer to black. But, by reading the histogram, you’ll realize there’s more detail than meets the eye! At the same time, if you over-edit your image, you can push the shadows to pure black and lose texture in the process. Use those clipping masks in Adobe Camera Raw and or Lightroom to avoid over-editing!
Not too bright and not too dark. That, in a nutshell, is the mid-tones of your image. Midtones are an essential part of any image. However, if only the mid-tones are captured, it results in flat contrast.
Highlights, the opposite of shadows… much brighter. Like with Shadows, your histogram can tell you if there’s more detail in this range.
Whites, the opposite of blacks… pure white or 100% luminance. If your highlights are “blown out,” then you’ll have complete, pure white. Over editing can cause details to be lost due to shifting the highlights too far.
To have or not to have pure black and pure white in your image? That is the question!
The answer depends on who you ask. Some photographers insist that photos should always have a pure black and white point. This way, the image will have the full tonal range of light captured. Others will disagree.
Who is right? Both! Actually neither! So, which is it?
It doesn’t matter what other people think.
What do you think? What do you like? What story are you trying to tell?
All that matters is your personal preference and the creative vision you have for that particular image.
Limitations In Our Digital World
All digital cameras have a similar flaw in the inability to capture the full tonal range of a scene. The darkest point to the brightest point might be too significant for the sensor to capture all the details.
Even if you’re able to capture the full tonal range, you could end up with disastrous results from editing. Let’s explore both to learn how to avoid these limitations.
Dynamic range is another digital phrase you need to know. It’s often confused with tonal range. But they are entirely different! Dynamic range refers to the ability or limitations of your camera to capture the full range from the brightest to the darkest areas of a scene.
If it’s too bright and your camera’s dynamic range is hindered by technology, your image might end up over or underexposed.
Dynamic Range Solution
Ever have “banding” in your image? The most common occurrences of banding are seen in skies and backgrounds of a solid color.
Banding occurs when there aren’t enough tones to create a seamless transition from one color to another. You can visibly see this since the shade of one color ends abruptly and is followed by a new color… creating a stair-step effect. This is often caused because your digital file doesn’t contain enough colors (tonal range) to smooth the transition.
For example, an 8-bit file consists of 16.8 million possible colors. A 16-bit file, on the other hand, has up to 281 trillion colors! More colors equal a smoother transition from one color range to another. Trillions of colors will also reduce the chance of banding during editing.
The solution is to use a higher bit depth. If you shoot in JPEG, then you’re limited to 8 bits since nothing higher is supported. On the other hand, Raw shooters can record anywhere from 8 – 16 bits, depending on your camera, of course.
My Nikon Z6 offers two-bit depths for Raw recording, 12, and 14 bit. For my photos, I’ve chosen a higher bit depth.
The downside is the file is about 30% larger vs. 12 bit. It’s a trade-off I believe is worth it since I’m able to capture trillions more colors and banding is practically non-existent.
You’ll also notice that if you shoot in 12 or 14 bit, for example, and open the raw file in Adobe Camera Raw, it will be converted to 16 bit! That is if you set up preferences to switch to 16 bit.
Now that you know what the tonal range in photography is and it’s limitations, you’ll be able to create exceptional photos. This can be achieved by capturing the full range of tones at the time of capture. Or if need be, by fixing it in post-production.
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