Hi. Sorry to divert from the purpose of this forum but there's some knowledgeable and experienced people here. Has anyone used the Tamron 200-500mm lens on a Nikon D40/60 camera. Does the autofocus work? (I've been googling this topic without much luck!)
Some SLRs (Canon for example) will not autofocus if the lens has an f-stop less than F5.6. That Tamron 200-500 is a F5 to something lens. So autofocus should be OK. but the moment you put a converter on, it drops to below F5.6 (F8 I'd guess). And the autofocus goes. But, not sure of the Nikon though.
I use a Tamron lens 70-350 lens on my canon 350. Autofocus and macro facility works fine. Japanese made at half the price. Very happy with the quality. Wish they made a flash. Paying 3500 for a canon flash is a bit wasteful.
Went for Nikon coz I noticed the lens and stuff was a bit cheaper than cannon. Can get a decent Nikon flash for R1600 thereabouts. The Nikon teleconverters are expensive though. I like this site for camera and lens reviews www.kenrockwell.com.