Quote Originally Posted by HDNitehawk
I shoot IS off when using a tripod with stationary birds. Just the motor kicking on and off you can loose a little sharpness.

HD, now you really got me confused again. before I bought this 500mm, I had been thinking to get a 600mm non-IS version since IS is not for moving objects and I can't handhold 500mm anyways. especially I have seen some good pictures took with this non-IS 600mm. then people told me that IS is very important for long lens even on a tripod, Bryan's review supports that we should leave the IS on when shooting with a tripod, Nate had a similar statment and he tune the IS off when shooting BIF. for me, personally I always don't care about IS that much even handhold the lens, birds are rarely be "stationary" even perching on the trees, my shutter speeds are almost always faster then 1/800, maybe 75% are faster then 1/1250. so anyway, which way should we go? I remember somebody in this forum had called the Canon but didn't get a very clear answer. I guess it depends, I need to do more test to find out which way is better for me.


thanks for bring this out!