Sometimes photos are called high key or low key. I never thought much about it and just made the photos I liked, regardless of what it could be called. But when is it correct to name a photo high key or low key? Let’s find out.
Sometimes I see photos that are named high key or low key. Just as often, I have my doubts about the use of the term. Often it looks like a deliberately overexposed or underexposed photo. On other occasions, these photos consist only of bright tones or dark tones, and no contrast at all.
I think photographers are only using the term high key or low key to make the photo more interesting. This is just my opinion, and that doesn’t have to be correct. I reached into my archives to find two photos that I think are high key and low key.
Definition of High Key and Low Key Photography
Are high key and low key special techniques, or just overexposure and underexposure? Or is it something completely different? I did some research to find out.
The first time the terms high key and low key were used is somewhere in the beginning of the 20th century. It is not something new. If you look at the name, the common term is the word "key." This is the name that is used when the average tonal value of an image falls in the extreme values of the tonal range. If the tonal values are mainly dark, it is called low key. High key is used when the tonal values are mainly in the brightest part of the tonal range.
High key and low key is also used in the film industry, where it is related to the use of key lights. But that is not what this article is about, although you may find a lot of similarities.
It is easy to translate the definition to the histogram. We know the middle of the histogram has a tonal value of 50% gray. When every pixel of the image is located at the left side, the image will be dark and it's called low key. The opposite is also possible. With every pixel located on the right side, the image is called high key.
A Strict Definition
If the term high key or low key can be used depends on how strict we hold on to the definition. Some people require every single pixel to be dark in case of a low key image, and light in case of a high key image. Not a single pixel is allowed to pass the 50% gray value.
If this strict definition is used, both the photos I found in my archives are not real high key or low key. After all, both photos contain pixels that are on the opposite of the tonal range. It is clear my opinion was wrong about these kinds of images.
The Difference Between High Key and High Contrast
Now we know that a high key has only a limited amount of tonal values. There are only pixels present that are brighter than 50% gray. This way the image will have a very fragile look, often without a clear sense of depth due to the lack of contrast.
If you add dark pixels in the photo, it won’t be a high key photo anymore if you hold on to the strict definition. If you also bump up the contrast on top of that, adding pure white or dark pixels, it will be a high contrast image. In other words, a high contrast photo isn’t a high key photo.
How About Low Key?
In the previous chapter, I have used high key as an example. This also applies for low key photography, of course. The difference is the location of the tonal values in the histogram. The dark photo I used at the beginning of this article can’t be considered low key because of the bright pixels it contains. It is also a high contrast photo if you hold on to the strict definition.
But if you look at the photo more carefully, is this really high contrast or just a photo that is mainly dark in appearance? Although it does contain bright pixels, the overall look is very dark. I even think this feeling is strengthened by the appearance of these brighter pixels. From this point of view the definition for a low key photo doesn't have be so strict, I think. The reality is more nuanced.
High Key, Low Key, and Also High Contrast
A commonly occurring problem with high key and low key photography is the lack of contrast. If an image consists only of bright or dark tones, there is a big risk the image will become uninteresting. This is not always the case, of course. But an image will get more impact when opposite tonal values are present. In other words, a few very dark pixels in a high key photo can make the photo much more interesting. Just like a few very bright pixels in a low key photo.
Although the strict definition of high key and low key restricts the use of opposite tonal values, it could make the photo much more interesting to look at. That is why you shouldn’t hold on to the strict definition. Just make sure the photo mainly consists of dark tonal values and you may call it a low key photo. It's high key if you have the opposite situation.
Is Overexposure or Underexposure Allowed?
You should be careful with deliberate overexposure and underexposure if you want to have a high key or low key photo. If you do, clipping will occur in most cases. This has nothing to do with high key or low key photography, even if you hold on to the strict definition.
A high key and low key photo will still have distinguishable details in the bright or dark areas of the photo. There should be no pure white or pure black in the photo. Just make sure you expose correctly, and make it real high key or low key in post-processing if necessary.
High Key and Low Key in Color
Almost every photo in this article is in black and white. This is not a coincidence, since high key and low key often work very well for black and white photos. But don’t be mistaken, it can also work with color photos. But it might be a good habit to perform post-processing color high key or low key in black and white. This way you won’t get distracted by colors. After all, you need to place the tonal values of the image, and it can be difficult to determine in which tonal range a color is located. I wrote an article about this some time ago.
Don’t limit yourself by using only black and white if you like high key and low key photography. With high key, pastel colors will often be dominant, and it can give the photo a nice atmospheric appearance. Just make sure you don’t overexpose your photo and call it high key, or underexpose the photo to have a low key. Because this is something completely different.
What Do You Think?
The things I mentioned are based on my opinion about high key and low key photography. I’m also interested in your opinion on this subject. Do you use high key or low key photography and how do you define it? Please share your opinion and your example photos in the comments below.
Interesting. I was under the impression that high/low key photography was not about the tonal range of an image, but the way a particular subject was lit (i.e. tons of light from multiple sources for high-key images versus less light, from a single source, for low-key ones). Maybe I'm wrong, or maybe there are multiple ways of using the same terms. Either way, this was an enjoyable read. Thanks for sharing!
True. The way a subject is lit has also to do with high key.
I can't imagine where you got your "strict definitions" of high key and low key. For the last forty years or so I've been doing it, "key" referred to the predominance of light tones or low tones.
In the days before digital, the test was whether an averaging reflected light metering of the scene reported the exposure to be underexposed (below middle gray), which would be low key or overexposed (above middle gray) for high key.
However this did not mean the scene was actually under or over exposed, but how an averaging meter reported the exposure.
The critical thing was that whether high key or low key, all values from pure black to pure white should always be represented. The difference was that in a high key scene, higher (above middle gray) tones predominated; in a low key scene, lower than middle gray tones predominated. But the full range should be present.
In the digital era, that should be what we see in a histogram. A low key scene should show tones mostly on the left--but there should still be a small amount all the way to the right, and vice versa for a high key scene.
Exposure should be accurate. The key should be created by the choice of tones in the scene and the way the scene or subject is lighted.
I found that definition in a couple of PDF papers (unrelated to each other) on the internet.
Thank you for sharing your thoughts. I totally agree on the last sentence, about an accurate exposure
I don't know where you found your strict definitions of high and low key imagery, but I have never seen or heard of those definitions before reading this article. But then again, I never actually researched the terms - I've just seen them in use a lot. I guess I base my idea of a term's meaning on how it is actually used by most people using it, rather than by going off of what some "authority" says it means.
To me, "high key" and "low key" images are just images in which the overall tonal value is light or dark, respectively. Take an image that is mostly dark, and it is low key, even if there are some very bright areas within the image. Take an image that is mostly very bright, and it is high key, even if there are some very dark, or even totally black, parts within the frame.
I see "high key" and "low key" as terms that are always used casually, and not things that have strictly defined parameters. That is how I see the terms used in real-world usage.
Another term that could be brought into this conversation is chiaroscuro imagery. The second I first saw your portrait of Iris (that you posted here in this article), the first thing that popped into my mind was "chiaroscuro". In fact, that term is so fitting for much of what you described in the article that I was surprised that you did not discuss it.
I am glad that you wrote this article. I love content that you guys create yourselves, when you actually expend great time and effort, instead of just posting a link to something that someone else has done on some other website. Nando, you are among the best at writing things yourself, and doing so thoroughly and articulately. You work your wording and phrasing over and over until it makes sense and is well organized. I respect you quite a bit for that.
You are correct... holding on to strict definitions has nothing to do with real-world usage. This also applies on the rules of composition.
This is an image I took a couple months ago. It is what I would call a high key animalscape.
Yes, some of the tones lie below the midpoint in the histogram, but the overall image is very bright, with the majority of the pixels clustered in the upper 15% of the histogram. Hence, in general vernacular, it would be considered "high key" by most artists and photographers who use the term.
To be honest, I don't think I would call this high key. There are too much midtones to my liking. Having that said, I do like the photo a lot. It is a great shot. I believe we shouldn't care too much about a name like high key or low key and just enjoy the photo as it is.
You, and others, may find this interesting. It is another article I found on high key and low key imagery, but it deals specifically with wildlife / bird photography.
Here's the link:
I think that the author of that article has a concept /definition of high and low key that is a bit looser than yours. Would you agree?
Thank you for sharing this article. It took a while before I read the text. Beautiful... no, amazing photos, especiallty from those spoonbills.
But I totally agree with it. I like the way he describes the use of high key with overcast sky, and low key with a sunny day. It matches exactly what I experienced: the last photo in my article is during a bright sunny day. The overcast I had are the ducks in the fog, and the color high key photo. I never thought of putting this into words like that.