Sigma Lenses for EOS 1D and frame rates

[JGordon]

I am looking to purchase anEOS1d for an unusual application, photo-identifying sperm whales. I was attracted by the fast frame rate available with this camera but have also seen that Canon state that this rate can be achieved when the camera has their own lenses fitted. I had planned to purchase sigma lenses which are somewhat cheaper. Does anyone know whether this would limit the frame rate?

Many Thanks for any advice.

Jonathan

[virterm]

Are you talking about any specific lens?
I can tell you that even with Canon's own 28-135IS the FPS is slower than with 70-200IS .
Wojtek