OK, I'm really confused now about crop factor.....
I have a crop sensor camera (Rebel T1i). Lately I've only gotten "only for APS-C" lenses because if I get lenses for Full frame "and/or" crop sensors....then I have to take the crop factor into consideration.....so if it's a 50mm lens...multiply it by 1.6 making it more like: 78 or so.
From what my friend told me (which seems to differ from some reviews--not all--is that if you get a "crop sensor only" lens, what you see is what you get....so 50mm means 50mm). This seems to make sense to me...........because:
- for example, my Rokinon (Samyang) fisheye lens is made only for crop sensors. The fisheye is normal--like it should be. If put on a full frame--is is kinda unusable--distorted and I think there is a black ring around the picture--but not like a fisheye that's made for a full frame.
- The lens I have now--Tamron f2.8 17-50mm is a terrific lens that is ONLY made for crop sensor - it is very wide. In fact a little wider than my standard kit lens 18-55mm that came with the camera...... so does that mean I'm still only seeing 17-50 X 1.6 because of the crop factor??
- The Tamron f2.8 28-70mm (I think) works on BOTH crop and FF. 28mm was really too narrow to be my all purpose lens. I had to stand too far back........I'm guessing this is because it's 28mm times the 1.6 crop factor....making it more like........44mm
- I've had the common f1.8 50mm canon lens (I think only for APS-C) and that is pretty narrow.......50mm makes sense when compared to the 44mm (28mm x 1.6) on my previous lens..
So.. this Sigma 30mm f1.4 that I've decided to buy is only made for crop sensor....is it gonna be 30mm? I've read in some reviews that it'll be more like 50+mm........maybe the reviewer didn't know what he was talking about? He also recommended the Canon 28mm f1.8 which was more sharp and about the same price, BUT for a crop OR full frame........and I believe he said on a crop sensor it'd be more narrow than the sigma 30mm...
so I'm confused.. I'm guessing it doesn't make sense for me to get the Canon 28mm b/c it'll be way more narrow than the Sigma 30mm......am I correct in assuming this? People were recommending the 28mm canon if you ever planned on going to full frame....which I dont plan on for probably 10 years......I think once I upgrade to a 7D in the next couple years or so, I'll be set for 10 years... -_-
Edited by hyogen - 5/23/12 at 7:58pm