Dizzy from lens spec's.....help!


TPF Noob!
Dec 13, 2007
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Ok so the post regarding lenses for the Nikon D40/40x has made me do a little more homework.
Problem is that there is soooo many different lenses out there, how do I know what will work with my D40's auto focus needs? I know AF-S, easy right!

I posted a link from Nikon's page below......I'm guessing all of these will work.


What do the 18-55mm numbers mean to me? and what letter must be there to work on Auto focus?

I really don't know the difference between lenses and am looking for some clarity. The AF-S DX 55-200mm F4-5.6G ED looks fair priced to me? So why the major price difference?

Ok, the numbers indicate the focal length 18mm to 55mm ( the zoom ). 18mm being wider then 55mm and 200mm. the f/# is the aperture size. A lens that says f/4 means that that is the max aperture for that lens and f/4-f/5.6 means that at the widest focal length the aperture can be f/4 but as you zoom it in the aperture changes till it reaches f/5.6 were it will hold. The Lens that focus on the D40/D40x are all the Nikon lens that say "AF-S" Also the Sigma lens that say "HSM". Those are focus motors in the lens so they work fine with the D40. I have the Nikon 18-55 AF-S lens and the Sigma 70-200 HSM lens and they both work. I hope this helps as this is an amitures words:)
Nikon lens acronyms

Photozone lens reviews

Some more light reading for you.

The 18-55mm is the focal length range for that particular lens. The D40 does have some limitations for autofocus lenses, but I can't remember what they are. Pretty sure several threads discus it though.
I like that second site:)

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