28 1.8 or 50 1.4 on a crop camera

The crop factor really isnt a huge issue here since its just the FOV. Although the glass on the 1.4 is better throughout (good for FF & 1.3x users)

the question seems like what is the ideal lenght for a piece of string. if you are ranging between a 28 and 85 get a zoom imho.

get all 3:
ef 28/1.8
ef 50/1.4
ef 85/1.8

I've had a 50mm f1.8 and have a Sigma 28mm f1.8. In terms of focal lengths on a cropped slr, I'd say the 28mm is more like the old 50mm on a FF. Fifty on a cropp is more like a 85mm, good for headshots but a bit too long.

Really depends on your shooting distance style, but I think the 28mm would be more versatile and the speed difference is pretty minimal.

Why not the Sigma 30/1.4??

28/1.8 definitely. She's a gem.

I had a similay dylema and dicided for a crop of 1.6 the 35mm F/2 was right for me based on focal length (56mm), f number and cost

Since you have the wide covered with the 17-40, I'll suggest the 50mm F/1.4. Probably my favorite lens. The 85mm F/1.8 is another very good lens. I seemed to enjoy shooting with primes over zooms, so the 28mm lens has been one I have been considering for over a year now, but I'm also considering the 24-105mm IS and the 135mm F/2.0 prime. To many choices. The 17-40 must not be fitting your needs, so I assume that is why your wanting a faster prime?

Neither. But get the 17-55 IS EFs instead of the 17-40L.
28/1.8 and 50/1.4 are both nice lenses, but IMO the 28mm isn't of that much use on a crop camera, and the Sigma 30/1.4 would be more interesting there anyways. The 50/1.4 is a nice length for portraits, but I'd rather have IS and a stop faster aperture then the 17-40L offers... If you have to buy one of the lenses mentioned in the poll, the 50/1.4 is a more usefull FL IMO.

René Damkot wrote in post #2127084
Neither. But get the 17-55 IS EFs instead of the 17-40L.
28/1.8 and 50/1.4 are both nice lenses, but IMO the 28mm isn't of that much use on a crop camera, and the Sigma 30/1.4 would be more interesting there anyways. The 50/1.4 is a nice length for portraits, but I'd rather have IS and a stop faster aperture then the 17-40L offers... If you have to buy one of the lenses mentioned in the poll, the 50/1.4 is a more usefull FL IMO.

I want it too, but will only have the money i make off of my 17-85, so the 17-40 will have to do just untill i save up some more to get the 17-55