What's the advantage, or difference, of a camera lens with a fixed aperture?

Question

None of my lens' have fixed aperture. Whats the difference? I've been searching but can't find anything helpful.

Answer 1

The advantage of a lens with a fixed aperture is when you are using a zoom lens without a fixed aperture (80-300 F/2.8-5.6)

The longer the zoom the less light hitting the CCD or image recording device. with a fixed aperture (80-300 F/2.8) the same amout of light is able to hit the CCD at all lengths. Thats why fixed is better. thats also why they are more expensive.

Answer 2

I can only think of one camera that serious photographers use with a fixed aperture: the Holga. This camera is an inexpensive medium format camera beloved by photographers for its eccentricities and imperfections. It has a fixed aperture of f/11. Its affordable and cool, but it certainly doesn't have a technical advantage.



From a theoretical standpoint, I could imagine that a fixed aperture could be made perfectly round (instead of rounded blades), which would make a very pleasing bokeh. I doubt I'd rush out to buy one, though.



*EDIT* The respondent below realized that you were probably talking about a zoom lens with what I usually think of as a "constant" aperture. The advantage is that your lens will have the same maximum aperture at all zoom ranges. So props to that other respondent.

Answer 3

About the only difference is, a fixed aperture lens implies a very basic camera.



The advantage being that if one knows little or nothing about photography, such a camera might be easier for them to use.