Welcome to the Essential Light Photography Blog By Jim Sabiston

Monday, September 6, 2010

If I had a camera like that...

A slight change in direction for this week. I was going to post about more extensive processing techniques, but it occurred to me that there was a topic that might have more immediate benefits for some of you. I will take up the processing discussion on a later date. Instead, I will discuss how to use the more common point-n-shoot camera to obtain better photographs.

A frequent comment I hear at the shows is “if I had your camera, I could take those good photographs, too.'

Well, maybe yes, and then again maybe no. The fact that they are making that statement tells me that they don't really understand photography, so its probably 'no'. Does pro grade equipment take better images? Of course it does, why else would we spend $1,500 on a prime lens or far more on a pro grade dslr body if it didn't improve the quality of the photographs we take? But, in truth, it is only part of the answer. That good glass and pro dslr combine to give some amazing potential for the photographer. But there is the key word: potential. Higher resolution, better quality pixels in larger sensors and world class glass are going to contribute something to the final product, but it is the photographer that determines the results. The main advantage of the higher grade equipment is this: control. The photographer simply has much more control over what the camera is doing. The typical consumer camera is largely an automatic device, removing all the decision making from the photographic process. For the average user, this is actually a good thing, allowing them to take far better photos than would otherwise be likely. The problem for the more capable photographer is that the averaging software that makes these cameras work tend to produce 'average' photographs. Good photography requires that the photographer put something of themselves into the image. In short, this means the photographer must control what the camera is doing. This, in turn, means the photographer has to understand how the camera works. This means much more than pointing the camera at your subject and pushing the big button. A real measure of a good photographer is one who can take great photographs with less than ideal equipment.

I will touch on some of the options available and cover a few of the simple tricks to help you along with those all-to-common automatic point-n-shoots to get better images. The first thing to do is familiarize yourself with the equipment you happen to have. We will assume for this exercise that the camera is a typical, completely automatic consumer camera. I will be using a Canon sd550, a pretty typical example of the type: decent build quality and feature set, 3X zoom, auto everything with some optional style and environment adjustments. This camera is a few years old now and has provided good service as the basic go to camera for family photo album type shots.

The good news is that new cameras are offering more and more manual control options. Even this 'older' camera has some things we can adjust. A quick look at the rear of the camera and I see a dial that lets me switch to one of several modes, fully auto, Manual , Scenes and video. The Manual setting is the one we are most interested in. This opens up several control options which are very useful, if a bit limited. The first and most important is Exposure Compensation, right at the top of the menu on the little Canon. Exposure compensation is a tremendously useful feature that allows you to adjust the scale on which the camera averages the image exposure. The adjusting range is usually plus or minus two stops of exposure (this is a significant amount). Adjusting increments are in 1/3 stop increments, giving thirteen setpoints.

In a full sun shot with some shadows, the camera will average the exposure such that it gets what it considers the best overall balance. The result is that the brightest spots will be 'blown out', that is, that part of the image will be pure white. This is because the amount of light will actually exceed the range of the sensor's ability to record it. At the other end of the range, the deep shadows will probably lack detail and may even be completely black.

I took the sd550 out in the yard and took three shots of one of our young cats. The shots were taken in the exact same conditions: Full, bright mid-afternoon sun. I took a shot at the two extreme ends of the adjustment range and the center (normal) setting. We will start with the first shot, with the exposure compensation set to -2 stops:

(click on image to enlarge)            Photo #1: Exposure Compensation= -2

Note the overall shot seems a bit dark. The mid range of the photo has been dropped down significantly, but most of the image retains good detail. Look at the shadows and you will see that the shadows are completely black, showing no detail at all. On the other hand, the whites of the fur retain full detail and color. This is the tradeoff at the low setting. Now, watch what happens when we restore the exposure compensation to '0' , the normal default setting (bearing in mind the furball model refused to sit still for the shoot!):

(click on image to enlarge)             Photo #2: Exposure Compensation= 0

This is the normal image you would get under the full automatic setting. Note the light and dark extremes have been averaged. The result is that the shadows now show good detail. The small bit of white fur is actually blown out to pure white, but the area is so small that I does not detract from the image. If the white patch was larger, the camera might have sacrificed some of the shadow detail to pull down the whites a bit.

(click on image to enlarge)             Photo #2: Exposure Compensation= +2

Last is the +2 setting. The change here is very dramatic, with almost the entire frame overexposed. Even the wood surfaces facing the sun have blown out to full white, retaining no detail at all. But look into the shadow areas, especially beyond the bench, which were pure black in the first image and only retained moderate detail in the second image.

This exercise illustrates one of the fundamental controls available to the photographer. I typically use exposure compensation in brightly lit situations to lower the exposure by about 2/3 to a full stop. I shoot in full manual, so I make this adjustment on the fly. An automatic camera will make the adjustment for you if you use the option. The main advantage of this ability, as I most frequently use it, is that I can offset the exposure of highly reflective surfaces to retain detail in those areas of an image. I can refine the exposure in the body of the image later on the computer if desired. With high-end post processing software, I can adjust the light and dark areas individually to retain full detail across the entire image, compensating for the limitations of the camera sensor. Ideally, the user of a point-n-shoot camera can use this to further refine the images a bit better than the camera will, left to its automatic settings.

For the next entry, we will study a technique for 'fooling' the camera sensor to change the exposure setting to were YOU want it to be. See you then!

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