01-12-2012, 12:45 AM
I've tried the Sigma 17-70 and I've been suprise how is was more bright than my other lens. I've took the same picture my 18-55 and switch to the 17-70, with the same seting I end up with a over exposed picture. Is this just because the 17-70 have bigger glass in front? ( 72mm vs 52mm on filter size)
Which would mean that the bigger to glass in front, the better the lens will act in low ligth situation ( since you need to step down to have the same picture )
I'm not sure what the explanation for all this...
Which would mean that the bigger to glass in front, the better the lens will act in low ligth situation ( since you need to step down to have the same picture )
I'm not sure what the explanation for all this...