Hi Guys/Gals 
I come from a broadcast run n gun documentary background with the bulk of my work using the Sony F800's & Ex1's etc and now am finally entering the C100/300 world (I know its taken me a while )
Ive been using my C100/300 with a 24 - 105 and also have a Canon 18 - 135 STM but I'm not happy with either for obvious reasons: the 24 -105 is just not wide enough I always have to keep stepping back as my style is quite up close and personal. The 18-135 is a fantastic range but i need to leave it at constant f5 and the IQ is well generally very average.
I'm really needing a better quality lens to use, so do people have experience with the Sigma 17 - 70 f2.8-4? I could use this at constant f4 which would be 1 stop better than the 18 -135, but I'm just curious about its IQ. I'm also very interested on thoughts on the Canon 15 - 85 apposed to the 18 -135's IQ? is it a step up in IQ?
Re my last post about a best all round interview lens Ive just bought a Samyang 50mm T1.5 and a Tamrom 24-70 (ove the Canon as the Tamron has IS) So thanks to peoples input regarding this.
So any suggestions/opinions/thoughts on the above would be much appreciated Not many camera stores in my area 
Tom
I come from a broadcast run n gun documentary background with the bulk of my work using the Sony F800's & Ex1's etc and now am finally entering the C100/300 world (I know its taken me a while
)Ive been using my C100/300 with a 24 - 105 and also have a Canon 18 - 135 STM but I'm not happy with either for obvious reasons: the 24 -105 is just not wide enough I always have to keep stepping back as my style is quite up close and personal. The 18-135 is a fantastic range but i need to leave it at constant f5 and the IQ is well generally very average.
I'm really needing a better quality lens to use, so do people have experience with the Sigma 17 - 70 f2.8-4? I could use this at constant f4 which would be 1 stop better than the 18 -135, but I'm just curious about its IQ. I'm also very interested on thoughts on the Canon 15 - 85 apposed to the 18 -135's IQ? is it a step up in IQ?
Re my last post about a best all round interview lens Ive just bought a Samyang 50mm T1.5 and a Tamrom 24-70 (ove the Canon as the Tamron has IS) So thanks to peoples input regarding this.
So any suggestions/opinions/thoughts on the above would be much appreciated
Not many camera stores in my area Tom