Exposure vs. Aperture: Differences in appearance?

[ppc_michael]

I know that shutter speed can freeze or blur motion. Aperture affects depth of field.

Besides that, are there any ways that shutter speed or aperture can affect the "look" of an image? Like, why you would choose to control the amount of light with one or the other? I'm thinking in terms of... contrast, dynamic range, etc.

I tend to adjust the iris according to what kind of depth of field I want, and then control the brightness with shutter (and of course ISO to a lesser degree). I just want to make sure I'm not missing out on anything by doing it this way.

 

[JHacker]

Exposure is not a setting on the camera. Your exposure is a combination of multiple elements, such as aperture, shutter speed, & ISO. You can freeze motion with your shutter speed. Using a wide open aperture (lower #) gives you a nice and shallow depth of field (ie. a person is in focus and the background is completely blurred). If you took the same shot with a small aperture (large #), both the subject and background would be in focus. Freezing motion depends on what you want to achieve.

 

[ppc_michael]

Blarg! I meant shutter instead of exposure. I'll edit the first post.

 

[mcarnes]

You're not missing anything, that's the way I do it. The only other thing I can think of is if you are going for critical sharpness, which is usually a few stops down from wide open. But I'm sure you know that.

 

[Abstract]

There may be a very good reason why you want to use a smaller aperture and lower ISO. For example, maybe you want to shoot using a slower shutter speed to allow for blur. You could pan with a moving object (eg: biker) so that the moving object is in focus, while the background suffers from motion blur.

For example.....

 

[mcmadhatter]

Edges can look a bit wolly if the aperture is too extreme (e.g. > 20 ) on some lenses (particualarly my cheap ones), f11 seems to be a sweet spot for me.

 

[Westside guy]

Edges can look a bit wolly if the aperture is too extreme (e.g. > 20 ) on some lenses (particualarly my cheap ones), f11 seems to be a sweet spot for me.

Actually, on a digital camera this is due to diffraction, and will be true with all your lenses. And, the newer higher-pixel-count sensors will be more diffraction-limited than the older sensors (so - and I'm making up the exact numbers - a D80 might start showing diffraction fuzziness at f/13, whereas on my D70 I am "safe" to maybe f/16).

f/8 or f/11 are where my lenses are at their sharpest as well.