http://www.nikonchat.com/nikon-70-300mm-vr/
Nikon D40 Lens question, Can the nikon 70-300mm f/4-5.6G AF Nikkor SLR Camera Lens used with the Nikon D40?
because it seems like a good price only $ 130 for a 300mm lens but I read one critic wrote "The owners of the D40, you forget that this is not an AF-S," so I'm completely new to this, firstly what is the AF-S? What is Virtual Reality? And it work with my Nikon D40 lens? AF amplitude in a lens??
The D40 is Nikon's first DSLR to break with its tradition of including the focus motor in the body. Instead, users must buy lenses D40 with the focusing motor built into them (AF-S/AF-I). You probably would be able to mount the lens, but not be able to use auto focus. VR (Reduction vibration) is what the names of Nikon optical image stabilization. Autofocus is good to have but not necessarily required if manual focus is available. A camera / lens with auto focus does exactly what it implies: it focuses for you. This is a good thing to have when shooting moving subjects or action scenes quickly. It is useful in many different situations, but many photographers had been making a good life before his invention. If the objective in question has no a focus ring, the objective will be useless. If so, maybe yes, you can manually focus it through the viewfinder. If the D40 has the focus indication your job will be much easier, and if not, can be difficult for you to use, since it is a very slow lens. If you have a good pair of eyes and do not care extra work (and some who lost a photo-op), go for it.
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