Limitations You Should Know About Your Digital Camera (Or Phone)!
W.Y.S.I. NOT W.Y.G.
There are a number of people who think “What you see is what you’ll get” with your new digital camera. These people are simply delusional. If you’ve ever witnessed a magnificent sunset and had the presence of mind to capture that on your new camera, and were so enthralled that you couldn’t help but tell all of your friends about it, but then when the pictures came back from CVS your friends just look at you funny as if to say “You were bragging about THIS?”, then fear not; it’s not that your imagination is running amok, and it’s not all the fault of CVS. The digital camera is an instrument to help capture the beauty and grandeur of nature, but it is a man-made instrument with important limitations.
God vs. Camera
First there are sensor limitations. Your eye is still far superior to any camera yet developed; it still has greater resolution1, it can perceive and differentiate between a larger range of colors (when describing or comparing the capabilities of different cameras, printers, computer monitors, or other equipment, this is called the “color gamut”), and it can handle a larger range of brightness between the darkest blacks and the brightest whites (this characteristic is called “dynamic range”)2 - meaning you can pick out details in shadow areas that your camera would capture as a silhouette. Additionally, your eye doesn’t have the artifacts or flaws inherent in the recording process (the graininess of film or the noise of digital images are examples of this). To be fair, your camera does have capabilities your eye/brain doesn’t; in low light conditions your camera will continue to collect light for as long as you leave the lens open, while your brain doesn’t benefit from staring at something for more than 10-15 seconds (We were able to take advantage of that in our image “Oak Tree Graveyard”3).
To help cope with these limitations, there are a few things you can adjust on your camera to try to match the most receptive part of its dynamic range to the scene at hand by controlling how much light hits the sensor. These controls include the aperture (which is the size of the hole letting light into the camera) and the shutter speed (which controls how long that light can hit the sensor). A third adjustment, virtually ignored in film cameras and still underutilized, is to control the sensitivity of your sensor to light. Each of these three adjustments has different side effects that you, the photographer, can exploit artistically to capture the best picture. This was the topic of a recent blog post4.
For now, just know that you do have the option of letting the camera make these decisions; in fact with some cameras that is your only option. This option does come with a price, however. I’ll call these programming/firmware limitations. Controlling the camera in your absence is a small computer - a computer programmed by someone that has no idea what you are looking at when you take that picture. Consequently, that programmer has to make assumptions. As a result, this computer is really easy to fool. One assumption that could haunt you is that the camera thinks the overall light level of this scene should be an average gray. This may be suitable for most landscapes and portraits of regular white folk, but the camera will still try to adjust the snow from your winter vacation or the black bear in your summer close-up to the same medium gray. Nobody likes gray snow. Another assumption the camera makes is that the main subject of your photograph is the closest object, or it’s the object in the center of your view finder. As you take more pictures, you will notice that there are plenty of times this is not the case. In fact, your viewers would prefer you not always put the subject in the center of the picture (hence “The Rule of Thirds”5, but the topic of image composition would also merit its own article). When your camera guesses wrong, you have no choice but to take back control of these decisions.
Film vs. Digital
Were film cameras any better? Yes, and no. The film medium is better than today’s digital sensors in their resolution (although digital sensors continue to improve - and film doesn’t) and in their color gamut. As an experiment, take the same glorious scene with your film camera and your digital camera, get them printed, and compare for yourself. Most people will agree that the picture from the film camera is clearly better. But is it as good as you remember the scene from being there? Definitely not. And were the film cameras themselves any better in making foolproof assumptions? No way! Of course, if you make your own camera adjustments you don’t have to worry about this aspect.
The beauty of digital is not in its ability to accurately capture the glory of the scene before you - film, although still flawed, is better at that. And although digital cameras are more convenient, that per se, is not their most important feature. The saving grace for digital is that it is easier to correct or compensate for the equipment flaws after the fact. But these controls require self-control by the operator. We may discuss the good and evil of photo editing tools (like Photoshop) as it relates to this aspect in another article. Stay tuned! You may also want to review Nancy’s picture-taking philosophy.