Originally Posted by
vysean
Sorry that I'm late to the party on this thread, but I thought I would respond to one aspect of the OPs post regarding night focus, and I'd appreciate any feedback from others with extensive experience in this arena...
My experience with nighttime photography (I shoot landscapes at night) has been that focusing is hit or miss with variable focal length lenses (e.g. 18-70mm), and always fine with fixed focal length lenses (I use the 10.5mm FE for this) when focusing on objects at infinity. Where there is enough ambient light (moonlight usually) and/or the objects are close to the camera, the camera is usually able to autofocus regardless of lens type.
Dunno if that helps or not, or if that has been the experience of others. I never really tried it with my D70 and haven't gotten around to renting a D2X specifically to test night focusing.
Sean
It's not so much an issue of "variable focal length" but rather one of [a] maximum aperture and [b] the camera's built-in low-light focusing sensitivity.
As for [a], all else being equal, a lens with a larger maximum aperture will have better low-light focus capability and [b] the Nikon D200 is one of the best low-light, low EV sensitivity D-SLRs on the market.
The D200 also has a near infra-red focus assist beam that can be turned on or off as you choose.