Originally posted by dr_romix I just got off the phone with Sigma Technical support and they guy said if I have K-5 and not worried about low light high ISO, I should stick to 17-70. Both 17-70 and 17-50 use the same optics..The only difference is EX lenses have fixed 2.8 aperture and 4 year warranty vs DC lenses don't have fixed aperture and only 3 year warranty. He also said " As much as I would want to sell you 17-50 , if you have 17-70, I would hold on to that. I have the same lens and extra 20mm comes handy quite sometime. and in our lab test, I didn't notice a difference between the two".. now I'm even more confused..what do you guys think?
Interesting, because I do notice a difference in sharpness between my 17-70/2.8-4.5 and my 17-50/2.8. Maybe it's because my 17-70 is the older f/2.8-4.5 and not the f/2.8-4?
*shrugs*
Originally posted by dr_romix He also highly praised 17-70's macro capability compare to 17-50 which is not macro.
Note that the "macro" capability in the 17-70 isn't real 1:1 macro as such, but it does magnify more than the 17-50, and the 17-70 has a minimum focusing distance that pretty much allows you to focus right on the front element
Originally posted by dr_romix for general walk around, Landscape, street photo with K-5 what do you recommend my friend ?
In terms of pure versatility, I would say the 17-70. That extra range from 50-70mm will be useful, and my 17-70/2.8-4.5 served me well for about 3 years before I got my 17-50/2.8.
Having said that, ever since I got my 17-50/2.8, my 17-70/2.8-4.5 has been relegated to sitting at home, or in the bag as a backup lens.