06-16-2011, 01:46 PM
[quote name='simon_k' timestamp='1308216711' post='9287']
I tested it in the shop and outside where it was quite bright (about 1/500 to 1/1000s at f/2.8 and ISO200).
I guess the size of the lens elements is just too much for the motor. The 70-200 has the same problem. It's not slow but compared to the fastest Canon lenses Sigma should be ashamed of their work.
What I forgot to mention was the OS - it takes a second or so to work but the it is amazingly good. I managed to get shots at 300mm and 1/30s. You have to pixel-peep to see a slight blur.
[/quote]
These lenses have a rear focusing system so the AF unit isn't all that heavy.
However, it is unfair to compare a zoom vs a prime lens here.
That said Ring-USM is still the place to be in Canon land if this is a priority.
I tested it in the shop and outside where it was quite bright (about 1/500 to 1/1000s at f/2.8 and ISO200).
I guess the size of the lens elements is just too much for the motor. The 70-200 has the same problem. It's not slow but compared to the fastest Canon lenses Sigma should be ashamed of their work.
What I forgot to mention was the OS - it takes a second or so to work but the it is amazingly good. I managed to get shots at 300mm and 1/30s. You have to pixel-peep to see a slight blur.
[/quote]
These lenses have a rear focusing system so the AF unit isn't all that heavy.
However, it is unfair to compare a zoom vs a prime lens here.
That said Ring-USM is still the place to be in Canon land if this is a priority.