Sigma 18-50mm 2.8 or 24-70mm 2.8?

guitarmy · Apr 2, 2007

(nikon mount)

Alright, so I shoot a D50 and I have the (craptacular) kit lens. I was tossing around getting the 50mm 1.8, but was thinking that I might be better off ponying up the extra $400 or so and getting either 18-50mm 2.8 or a 24-70mm 2.8 (both Sigmas).

Any opinions on this? I realize the bigger aperture would be nice, but I'm thinking it would be of a greater benefit to have a focal range to work with as opposed to a fixed focal length. I hate the kit lens I have now, so I'm thinking this will completely replace it. Not so the case with the 50mm 1.8.

Any advice or opinions would be great. Thanks!

Big Mike · Apr 2, 2007

Those lenses are basically the same except that one is digital only (smaller image circle) and is wider.

Which focal length would you most like to have? 18mm or 24mm....50mm or 70mm?

guitarmy · Apr 2, 2007

Any benefit to the 'digital only' lens? I don't think I really understand it. Does one eliminate the 1.5X crop factor or no?

As for focal length, I think I'd prefer the wider end, and then I'd buy a tele zoom (probably the 70-200mm Nikkor). Thus it might be smarter to go with the 18-50mm.

Anybody have any comments on build quality, sharpness etc?

Big Mike · Apr 2, 2007

Any benefit to the 'digital only' lens? I don't think I really understand it. Does one eliminate the 1.5X crop factor or no?

The benefit is that you get a lens that is 18mm on the wide end...and it doesn't cost $1000.

'Digital only' lenses don't eliminate the crop factor...they just gives you a wider view.

Imagine you had a 35mm film SLR. The 24-70 would be a great lens because it covers the 'normal' range. Now if you put that same lens onto your digital body...it will 'feel' 1.5 times longer because the outsides of the image will have been cropped off (you would only see the middle portion of the image). So now 24mm (on that camera) can't see as wide of a view...so you are not covering the 'normal' range anymore. Bring in the 18-50, now you have your 'normal' range again.