Canon EF-S 17-55mm VS Sigma 17-50mm VS Tamron 17-50mm?

jitteringjr wrote:

Sovern wrote:

A 50 1.8 and 85 1.8, if you need wide angle just use the kit lens. 17-55 is short for portraits even on crop as the perspective does not change crop body or not.

The 85/1.8 is great no doubt about that, but the 50/1.8 is crap. Focusing is so hit or miss on mine, that I shoot at f2.8 anyhow just to try to get more DOF and have a chance of getting my subject in focus. The Canon 50/1.4 is soft as hell until f2.2-2.5 so you are really only gaining a 1/3 to 2/3 a stop there. The Canon and Sigma 17-5X's are sharp wide open at 50(55)mm.

Your second part of that statement really needs to be clarified. If you shoot with a 50mm lens on full frame and crop, from the same camera location, then yes the perspective would not change. The problem with that logic is that you are not shooting the same framing. You would have to move the crop camera back 1.6X times further in which case you are changing the perspective. Perspective is related to camera position not focal length.

Also its funny you mention the 50/1.8 if the 17-55 is too short for you.

Actually you're incorrect. The compression and perspective change is the same no manner what with the same lens. The only time that this changes is when using ultra wide angles or fisheyes where getting close causes more distortion.

If you take a photo at 200mm with a crop body and full frame the compression which is the perspective will be the same. The only difference is that the full frame sees the full lens allowing you to get closer to your subject and thus more bokeh.

Also, I recommend the 50 1.8 because at 1.8-2.0 it has great bokeh in my opinion (some don't like pentagon bokeh I don't mind it) whereas with the 17-55 at 2.8 you're not going to get that really shallow DOF.

I actually am not very fond of any of Canons prime lenses that are not L below 85mm though which is why I sold my 50 1.8 (however I recommended it because I liked it WAY more than the Tamron 17-50 2.8). Canon's 85mm+ primes are all excellent.

For a crop body or full frame body I'd actually really like to use a 35mm prime and 85mm prime duo set up for portraiture or any events with a 135L2 for telephoto shots.