Originally posted by heasley Can't say that I've had mine at -15C
Next to my other 2 primes (FA43 & Fa77) it is very weak.
I think I may have a bad copy.
Originally posted by axl next to 43 + 77 many lenses will seem weak
I was thinking the same. It is harder to make a wide angle work well at f1.8.
It's the only Sigma lens I have, so I cannot say anything about variability. Some say they have problems with that. But I was plesently surprised, only remembering the crap Sigma lenses from the 80's.
Lets see if Pentax ever makes something like a 20/2 how they compare. For sure they will build it better and most likely have better collors, but I'm not sure it will be sharper wide open. From what I see, stopped down to f2.8 it does OK against the FA20/2.8.
Sigma doesn't keep up with Pentax standards lens by lens, but they fill gaps that no one fill for us. Give them credit for that.