i see alot of people say get the 28-75 for FF and 17-50 for crop sensors.
is there any real reason not to get the 28-75 for a crop? unless you have a lens that covers that range?
i need a short (wide) zoom, and really both the 28-75 & 17-50 fit the bill and are in my price range.
the 28-75 used fits my price
but i am having a tough time with the decision.
i like the wide end of the 17, but the 28mm would suite me fine also i suppose. (but i have the sigma 30 1.4)
but i like the longer reach of the 28-75mm since i already have the canon 50 1.4 (but i also have the 85 1.8 )
from the pictures i see here it really doesnt matter on a crop as it performs quite well, it seems to be more of a how wide do you want or how much zoom do you want.
one thing i discovered about the 17-50 in testing 2 lenses at the local shop was that it was really soft @ 2.8, and had a yucky low contrasty haze to it. but when stopped down it cleared up nicely.
and i also had horrible focusing issues. i would not have purchased either lens from them i would have ordered a new one.
they did not have a 28-75 for me to test unfortunately.
so i guess my question would be is the 28-75 as soft wide open and does it have the low contrasty look to it wide open?
i have read here and there that the 28-75 is actually sharper than the 17-50, but can neither confirm nor deny that since i have neither.
You need to make the decision on what focal lengths you tend to use the most and get the lens that fits your requirements. However, if you don't already have a wide angle, then the 17-50 would probably help you cover those needs, while you're primes will take care of the longer lengths. Getting the 28-75 would limit you when width is what you need!
Both lenses are not soft (by any stretch of the imagination) at 2.8 unless you have a bad copy...and this appears to be the case in the one you used. I use my 28-75 wide open without any hesitation as its tack sharp and it has no trouble focussing as long as there is some contrast.