AF: D200 vs D300

I use a D200 with a 300/4 AF-S and TC17EII extender quite a bit. I've had the lens combo since I was shooting film with an F100, and the D200 performs about as well. For the most part, it's great, but in low-contrast situations, and bird-in-flight work, it often goes a-hunting while my subject goes bye-bye. I'm especially bummed when I've set the camera to closest-subject focus, and there's nothing but a bird in a blank sky, and the lens can't find it!

For the record, I have not found the lens to be any faster or less hunt-prone w/o the 1.7X on there.

I've heard all the stuff about the 54-point AF system of the D300, but what I've never heard specifically is whether it does a better job with low-contrast telephoto work.

I have no experience with that lens on a D200 and little experience with the D200 itself, but I can offer another comparison that might be illuminating. I was shooting both a D300 and a D2X mounted with 18-200mmVR lenses on an aerial shoot. The D300 beat the D2X hands down, not only for focus speed and accuracy, but also for speed of acquisition of the VR function. I lost a lot of shots made in tight, low elevation turns (airplane standing on its wing) with the D2X, but the D300 never missed a lick. On top of that, light levels were low and I had to shoot at 3200 ISO. The D300 produced vastly better results than the D2X, with virtually no noise in blacks and nice contrast and saturation. The D2X images were virtually unusable.

Yeah, I'm a fan of the D300 even if I can't respond to your question about that lens/converter combo. While we originally bought D300's as backups to our D2X's, the D2X's have quickly become backups to our D300's.

I just bought a D300s with the same lens setup you use and shot this morning and afternoon. I was worried the autofocus would be slow and hunt a lot because the aperture goes to f/6.7 but found it to be quiet fast and smooth. I even got some BIF shots which I never would have been able to get with my D60 55-200mm VR lens. The lens tracked the bird without a hitch. The one thing I DID notice however, is that when trying to find a bird with a blank BG if my original focus wasn't anywhere close it had a difficult time finding it and did quite a bit of hunting. One tip I received is to try to pre-focus your lens to what you think will be correct and then use the autofocus to zero in.

- Luke

John, I shoot a D200 also and have had the same issues as you. I use a Tamron 200-500, and the AF seems to be the issue. Trying to follow an eagle before and as it swooped in for a fish, only to have the lens start searching, became quite irksome. I thought it was me doing something wrong. Manual focusing takes a LOT of practice, especially if the camera is mounted and the object is being panned! (Still practicing, I have no choice unless someone else has an answer)