Since we are in "The Great Debate" again 
Can someone talk about lenses and autofocus speed and the difference between having the motor in the lense (?Canon) and the motor in the body (?Nikon) ???
I went to my local camera shop in hopes of finding the elusive D200. Of course, they have no D200s on the shelf and have no idea when they will get any. So, I tried the Canon 5D with a 100mm lense side by side with a D70 and a 60mm lens. (This was the closest I could get to "apples-to-apples" because the 5D is full format unlike most DSLRs which are 1.5)
Anyhow, even standing in the shop, focusing on a quarter or on printing on a box in decent light, there was simply NO comparison. The D70 autofocus time as very noticible - as in mulitple tenths of a second; It seemed as if it set itself at one extreme of focus and methodically turned the lens until it found the focus spot (even when set to limit the range, and without any searching).
With the 5D (and later with the 20D with the kit lense) you didn't even have time to think what the camera might be doing - bang the autofocus was set.
I ask the shop manager about this, and he says of course Canon will always win in autofocus time because the motor is in the lens. And if you shoot nature or sports photography, there is no reason to go to Nikon if you don't have an investment in lenses. At first I figure "Canon bigot", but I probe a little and he does make sense. But I have never heard this before in 6 months of research, and I don't trust anyone but the real experts here.
So, given that many of us shoot a lot in not perfectly still water, with not perfect bouyancy control, with not always immovable subjects, and of course not making contact with the environment, why is this not a highly determining factor in choosing a system?
I know autofocus speed is a huge factor for me in wanting to move up from my D5000 to a DSLR. Now I feel that I have to go to a 20D with a smaller display than I'd like or pony up bigger $$ for a 5D. This one simple demonstration has totally changed my thinking.
Did I miss this consideration all along or am I still missing other mitigating factors?
- Beth (education is a long process)