Sigma 28mm F2.8 "AF Super Wide" on DX?

Hi All,

I have recently purchased a Sigma 28mm F2.8 lens, which appears to be designated a "Super Wide". The lens appears to be working normally on my D80, except for an issue with the aperture - the widest I can open it is F3, not F2.8. This appears to be strange, as my Nikkor 28mm F2.8 jumps straight from 2.8 to 3.2; it doesn't stop at 3.

All other aperture stops appear to work as expected, and the lens takes some nice pictures, with fairly decent auto focussing (though it does sound pretty clanky, which I gather is expected of this particular model).

Can anyone suggest if this is a niggle with the camera-lens combination, or if the viewfinder display of aperture can generally be relied upon? I'm trying to determine if the lens is faulty, or if this is actually not a problem at all.

Thanks for any help!

I believe it's a function of your focal distance. Try focusing on something close vs. distant. You'll see that either the close or distant focus will achieve the 2.8 while the other will only go to 3.0. My 60mm and 105mm macro lenses do that same thing.

I find the "super wide angle" classification rather curious. 28mm in 35mm/FX is just a "normal" focal length wide angle lens, and on DX 28mm works out to be about a 42mm equivalent on FX, hardly what one call a "super wide". Maybe it is just a SUPER! wide angle lens.