Where Can You Find the Perfect Exposure?
Reprint from Shutterbug, September, 1995
With so much that has been written about exposure, the big question still remains for many. What is "the" perfect exposure? I want to add my two cents worth, in answering this question. I feel the answer lies more within ourselves than any exposure meter. I'll try to lift what is for many, a tremendous burden - obtaining the perfect exposure for their photography!
I think understanding the answer can be found in the definition of the word perfect. Webster defines perfect as "to finish or complete, so as to leave nothing wanting." It goes on further in defining the word by saying, "to make perfect or more nearly perfect according to a given standard, as by training or improvement." These two definitions apply directly to photographers' quest for "the" perfect exposure.
From my point of view, there should only be two criteria for the perfect exposure. First is how and what you want to communicate in your photograph (to finish or complete....). Second is what reproduces detail in either the print or printed page (to make perfect or more nearly perfect...).
Our Perfect Exposure
We tend to lose sight of what photography is really about - communicating. We don't have brush strokes available to us to emphasize the subject. We can't give rise with a crescendo to bring drama to our subject. We can't even add the perfect adjective to better describe the subject. What we have to communicate with is light and how we expose for it.
Light is what gives life to our photograph, and exposing for it is what defines our own personal perfect exposure. For example, we can tell from a photograph whether it was taken on a sunny day or overcast day. We weren't present at the time of the exposure, but the quality of light and how it was exposed clues us in as to the time it was taken. But was that what the photographer was trying to communicate or were they just following "the rules?" A sunny afternoon can be underexposed to darken the scene and an overcast day overexposed to brighten the scene. All of a sudden we have taken control of exposure making. We've now changed the scene to fit our desire, we're now communicating by finding our perfect exposure.
There are a number of common situations that mess up the photographer's mind when it pertains to exposure. The most common is snow. Oh my goodness, the number of letters I've received on how to expose for snow. The rule so often quoted is overexpose by at least one full stop. I hate rules! "You" have to decide what's the subject and then expose for it. If the subject is the snow and you want to see detail in its crystals, then overexposure is called for. But if the snow is a mere element in the photograph, overexposure is probably not going to give you the perfect exposure for what you're communicating.
Now this holds true for other light subjects as well as dark subjects. The white bird on blue water has to be the ultimate nightmare for the quest of the perfect exposure. But with my formula, it's quite simple. If the white bird is the subject, then overexposure is right. If the white bird on the blue water is just an element, then overexposure is not needed. And when do you know which is correct? What is it you want to communicate?
This is why I've put this discussion of the perfect exposure first, because it is the most difficult. There are no rules to go by. There are no formulas in which you can attach to a scene to decide what it is you want to communicate. You, the photographer, the communicator, must make the decision on what it is you want to say. The disappointment many feel from their photographs when it comes to exposure is not from detail missing in the highlights or the shadows (to be discussed in a moment), but because it does not communicate what we wanted about the scene.
The Focal Encyclopedia of Photography, third edition says this about the perfect exposure, "The correct exposure for a photograph can be defined as an exposure that produces an image with the tonalities and colors the photographer desires,...". In this pursuit of communicating, technical expertise in exposure is important. Don't get me wrong, you must know what you are exposing for to communicate. But it is not the dominating factor, at least in my way of thinking, of the perfect exposure "....to leave nothing wanting."
The Technically Perfect Exposure
The math of the technically perfect exposure really isn't that hard to spell out. Positive film (sorry, I can only speak for the film type I know, others differ), has generally an exposure range of 2 1/2 to 3 stops. This means that any highlights or shadows in the scene within this exposure range contains detail. But this very phrase might create confusion for you rather than clear things up, so let me elaborate.
A scene has a range of exposures for each and every element contained in it. The proper exposure for an element in a scene is when detail can be seen in that element, detail such as leaves, ruffles in a cloud. etc.. For example photographing a sunny scene (shutter speed for this example not relevant though would be constant for all), to expose for the highlights such as a cloud, an f/stop of f/16 might be required. Proper exposure for the shadows, the leaves at the bottom of a bush, might require an f/stop of f/5.6. If the highlights of the scene can be properly exposed at f/16 and the shadows at f/5.6, then they fall within the 2 1/2 stop range and detail is captured throughout the scene. In our photography we find this the exception and not the rule. (Obtaining the exposure for this scene can be derived in a number of ways and in itself is another article/book.)
Generally, the exposure range of our scene is greater than the range of the film. Depending where we place our exposure, either highlight or shadow detail is lost because it falls outside this range. This means that either highlights are burnt up, washed, or the shadows are blocked up, black, neither holding any detail. When this occurs, these photographs are referred to as "contrasty."
In the quest for the perfect exposure, solving the technical side is easy to answer. Typically, we expose for the highlights and pump light into the shadows to bring them up within the magical 2 1/2 to 3 stop range. We have such tools as fill flash and reflectors to help fill in shadows. Their proper application when not detectable, lowers the exposure range of the scene so detail can be captured, while effectively communicating. (If you look closely at my photographs, you'll notice that I typically let shadows go dark in scenics while with wildlife, there is shadow detail. That's just my personal preference for the perfect exposure.)
Highlights can be tamed with polarizing and split graduated neutral density filters. These are generally applied to large scenes where the shadows are too large to be filled in. By exposing for the shadows, these filters hold back the highlights by underexposing them. In this way, they are brought within the range of the film's exposure range. Now the polarizer will only do this when properly used to eliminate reflections and not just turned to create blue skies. (I tend to overexpose by 1/3 stop when using polarizers to bring up shadow detail just a tad.) The split graduated neutral density filter underexposes an area of the scene by as much 3 stops. This means a scene with a 6 stop range can be condensed to fit within the 2 1/2 to 3 stop range of the film.
Now means of metering to determine the proper exposure for various elements or scenes can vary. Preferences for exposing for the highlights or shadows can likewise vary, but the fact that we have this 2 1/2 to 3 stop range remains. The technical question of the perfect exposure lies within and outside this range. It is a question you can answer by simply applying the many tools available to us effecting exposure. Understanding where to base your exposure to capture this range can be accomplished by lots of trail and error, or doing my Teddy Bear Test.
Just to provide you food for thought, when you have a photograph where the highlights and shadows are within this range, you have the perfect exposure for prints or the printed page. I still contend this might not be the perfect exposure for the scene or what you want to communicate, but it will render the perfect print. This includes providing the ultimate in sharpness. There's no doubt that sharpness of an image is at its greatest when the exposure is within this range "....according to a given standard... "
Obtaining Your Perfect Exposure
But you're saying, "Moose, how do I know what I want or what happens when I apply a filter or underexpose?" Experience is still the best teacher because we all see differently and communicate differently, but I can provide you some insights as to what I do.
An example is shooting on overcast days. This to me is a magical time for photography. The exposure range is generally within the 2 1/2 to 3 stops without having to mess with flash or filters. Now if the scene has a definite mood to it, such as a stormy coastline or trees in fog, I expose as the meter advises. This generally underexposes the scene creating a darkened image. This creates a dark mood to the scene, communicating the mood I felt while making the exposure.
But I have found I can take this same overcast light and change everything by simply overexposing. Photographing in forests, or other normally contrasty places, are best when it's overcast. But by exposing for the mood, the scene becomes very dark and gloomy. This is not what I want to communicate in many instances. So simply by overexposing by 1/3 to 1 stop, I can change the scene dramatically. How dramatic? You won't even know by looking at the scene for example, that it was raining because it looks so bright. The thing that gives the technique away is that the highlights and shadows still hold detail.
Changing the exposure range to communicate what you want affects other elements in the photographic equation. Beware that for every action, there will be an opposite and equal reaction. By changing the exposure to obtain your perfect exposure, such things as contrast and color changes. Underexposing a scene generally saturates colors more where overexposure washes them out. The rich greens of a forest like the underexposure where the pastels of a field of flowers like the overexposure. And of course, the exact opposite might be what you like to capture.
So where have I led you in this discussion of the perfect exposure? Hopefully right back to where I wanted, to you. I want you to understand that the perfect exposure is what you like. You are the final judge as to what is perfect or not. You and only you know if what you saw in the scene is what you captured and communicated successfully. And you will know this not only from your own reaction to your image, but by the reactions of others. Anyone can master the technical side of exposure. Heck, most modern cameras can obtain the correct exposure for 90% of the scenes we encounter. But the real pro, master of one's craft of communicating, must reach down deep inside to master one's own perfect exposure. You won't find the answer to the perfect exposure in my words, but only in your photographs.
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