Digital cameras 101

[rhinorick]

Does using a smaller or larger aperture setting affect the details in a photo?

It seems to me I read somewhere that using a smaller aperture (larger number) will give more precision/sharpness to the details in the photo.

It seems to make sense, but I just wondered what you guys thought.

[bdery]

The aperture value will, indeed, affect the detail of an image. Lenses are generally sharper one step below their maximum aperture (sometimes two steps). As you close the aperture, the "hole" where light travels gets smaller, so this starts to create what is called diffraction effects, makin the image less sharp. With DSLr lenses, this often happens at around ff16, with most digicams, it happens well before that. For instance, with my S2 there is a drop in resolution as soon as f7,1. That's because, given the size of the sensor, the atual hole is much smaller (for a given aperrture value) on a P&S than on a DSLR.

Aperture also afffects vignetting, focal range, chromatic aberrations, etc.

[ShutterbugGail]

The main reason I pay attention to aperture is when I want to control what is known as "depth of field." Here is some information about this important photographic, creative control technique:

Aperture:

http://www.digicamhelp.com/camera-features/advanced-settings/aperture.php

Depth of Field:

http://www.digicamhelp.com/taking-photos/advanced-techniques/dof.php

http://www.digicamhelp.com/taking-photos/advanced-techniques/dof-guide.php

[rhinorick]

Thanks bdery and Gail.

I knew that aperture changes depth of field.  I have had lots of fun with that.  Great links Gail.  Thanks.

I am at the point now where I am learning (investigating really) the detail question.  So bdery, you are saying that there will be a loss of detail the smaller the aperture gets (i.e. the larger the f-number)?  I am surprised.  I thought it was the other way around.  That is good to know.

Does "one step below their maximum aperture", mean like if my lens goes down to f/3.7 (largest aperture, smallest value for my lens), then the sharpest image my lens will take is probably at the next f-stop, which is f/4.0?

That is really good information to know. Let me know if I am understanding it right.

Thanks guys!