When I explain what a SLR/DSLR camera does regarding aperture and shutter speed, I try to liken it to a see-saw. If one is up the other is down; There always has to be a point of balance. For myself I always decide what is the most important thing concerning the subject at hand. There are lots of variables, but speed, light, and depth of field are the biggies for me. I tend to shoot in shutter priority, because I am lazy and don’t enjoy lugging my tripod around. Shooting in shutter priority I know will give me a fast enough shutter speed to keep the image from being blurry. I also am lucky enough to have an auto ISO (“Film” speed) so my camera can adjust the ISO according to the available light. I don’t have a flash, don’t like the tripod (which would give me better photos but a neck and shoulder ache), so in low light my photos are a bit grainier (noisier in digital land). But for now, that is ok by me, because I am trying to have FUN! Sometimes it is fun to play with the aperture. Notice how one image is more in all over focus? That is the small little opening (22 or so). The depth of field is a long range compared to the very short range of depth when using a wide-open aperture. When shooting little flowers and things (or a portrait), I like a short depth of field, otherwise it just looks like a reference photo. “Here is my plant”. “Here are my rocks”. When a large aperture (small number) is used, those photos become artistic and interesting. The eye sees details in a different way and focuses on the inherent beauty of the subject, the flow of the image as a whole. All that and they are just some things on my deck using a large aperture, creating an interesting focal point.
ArtBea 