Tuesday, September 14, 2010

Exposure

I strongly believe that the most prominent problem with having no formal training in photography for me is not knowing anything about exposure. I rarely switch from the auto-focus sport mode on my camera for this reason, even though I know it handicaps my ability as well as the camera. The only thing I really ever did to change the lighting of the picture was to turn the flash on or off or change where the sun was in relation to the subject if possible. My interest in photography is more to capture special moments and take pictures for my family and friends to enjoy, so I never really worry about any manual settings on the camera to change exposure. After reading the chapter on exposure, I am starting to think that manual settings could help more than I thought they would originally. It seems that the things I enjoy most climax at sunrise or sunset, or shortly thereafter, which can lead to some difficult situations to shoot in a pre-programmed mode. The best hunting and fishing times are usually near dark, when it is very important to pay attention to exposure, and also the times that I want to capture the moment.

Before reading this chapter, the histogram was only that annoying thing that popped up on the viewfinder if I accidently pushed some button that I then had to figure out how to undo. I now see how the histogram can be very useful. On a histogram, tall bars on the far left side can mean that the photo is underexposed, and something in the picture is black. Tall bars on the far right sixe can mean that the photo is underexposed, and something is very white. This can also be advantageous if the effect you are looking for is a black bird silouhetted against the sunrise or if you are trying to capture the whiteness of snow or something else that should be pure white for example.

Light metering is something that I had never even heard of or considered as something that could really affect the way my pictures turn out. Once again, I rarely find myself shooting in an average light scene because of the things I enjoy taking pictures of, so this could have a large impact on my picture quality. The reading suggests evaluative or matrix metering as the go to mode for most situations. This takes light from 15 to 30 different points on the scene and makes the exposure using real life algorithms. Spot metering may be useful for me as well because it makes sure that the main object of importance is correctly exposed. I think this could be a good option when trying to take picture of my dog at close to mid range. Another option is center-weighted metering but this option focuses on only about 75% of the frame, and even I know that the middle of the picture isn't usually where you want to focus your main subject.

There are a few different modes on my camera that let me have more control over exposure than the pre-programmed modes. Aperature priority mode allows me to choose the aperature while the camera decides on the shutter speed. The book suggests using a large aperature size for shooting moving objects such as wildlife, or my dog that won't sit still for a picture. Shutter priority mode is the exact opposite of aperature priority, and full manual mode allows me to control both aperature and shutter speed.

The suggested way to deal with the difficult and strong lighting at sunrise and sunset is to take a spot meter reading of the sky not including the sun. This ensures that the exposure of the sky is correct, and the rest of the picture will usually go with it. After getting the reading from the spot metering, the photographer should use the same exposure settings and take the picture the way that they want it to be. Then all is left is to hit that once annoying button that now leads to the useful histogram that will give an idea of what the lightest and darkest parts of the picture will look like.

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