Will sluggish aperture blades affect my pictures?

[Rol_Lei Nut]

It should indeed.

If you set, say, f/2.8 on an f/2 lens, and the aperture blades don't close fast enough, you end up with (worse case) a full stop overexposure.

In my experience with sticky apertures, all except the worst cases manage to close at least partly before the shutter opens...

The test I mentioned - observing the aperture with an open back from behind - try that on your favourite sticky aperture lens, you might learn something!

[John Koehrer]

Most of the Oly lenses I've serviced for sluggish operation have been from lubericant at the rear or the lens. It's a pretty easy fix though, usually three cross point screws and everything come straight off. There may be a spring connected to the mount and a pin in the body so remove it carefully. Note the alignment before you take it apart it needs to go back the same way it came out. Test the aperture before you put the screws back in to be assured everything is copacetic.

[EASmithV]

Yes.