lens autofocus

[atvinnys]

I am somewhat confused by something I read lately.
I think the post was stating that some camera bodies (nikon high end I think) had an internal focus mechanism that would allow the use of non AF lenses.
is that a myth or not? and if not, how would that work?

[McQ]

I do know that with Canon SLR cameras you can never use autofocus with a non-autofocus lens because the focus motor is in the lens itself. However, all Nikon SLR's up until recently have an autofocus motor in the camera itself. More recent Nikon digital SLR's do not (such as the D40 onwards), except in the really high-end models. Based on this it seems likely that what you are saying is completely true...I just do not know which lenses it would work with. If you look at the camera's lens mount and the back of the lens in question you should see a matching electrical contact to drive the lens's focusing. Other than by visual inspection I'm not sure how else to tell whether the camera & non-autofocus lens combo will work using autofocus.

This may not be what you have in mind, but you can often use non-autofocus lenses on high-end SLRs (both Canon and Nikon) if you manually turn the focus ring and use the camera's autofocus lock light.

[Raycer]

Nikon D40, D40X and D60 do not have AF motor in the body. They need the "silent wave" motors in the lenses.

Nikon D50, D70, D80, D100, D200, D300, D1, D2, D3 all have worm drive in the body. They still need AF lenses.

For body-lens compatibility chart, check this page:
http://www.nikonians.org/nikon/slr-lens.html

[atvinnys]

well, more used to Canon, I really thought all SLR were relying on AF lenses.
so for Nikon camera bodies that have an AF motor, is there basically a mechanical connection at the lens mount for control of the lens elements?

I browsed some but couldn't find anything really..I would be interested to see how it works.
thanks

[tirediron]

Yes, all of the higher-end Nikons (D1, 2 series, D3, D100 - 300, and the D70/70s) have a motor built into the body which connects to the lens via mechanical coupling and allows the use of older-style auto-focus lenses which do not have a built-in motor (In Nikon parlance, AF-S for "Auto-focus - Silent Wave"). Any non-auto-focus lens can still be used, but you will have to focus manually.

This image: http://a.img-dpreview.com/reviews/Ni...ensmount01.jpg is the lens-mount of a Nikon D300 (all others identical). If you look on the lower-left at about the '7 O'clock' position, you will see a small + between to Phillips head screws, that is the auto-focus linkage for use with non-AF-S lensses.

Hope that answers your question.

[atvinnys]

yep, just what I needed to know.
Thank you all for the details.

[Raycer]

just thought about this...
I guess you could set up the camera for trap focus, then manually turn the focus ring. Once the subject is in focus, that should trigger the shutter. I'm gonna give this a try and let you know if it works.

[Raycer]

dooh!
it looks like when paired up with a manual focus lens (or when I tried it, lens was switched to manual focus) the shutter release button will trigger the shutter whether its in focus or not.

[tirediron]

dooh!
it looks like when paired up with a manual focus lens (or when I tried it, lens was switched to manual focus) the shutter release button will trigger the shutter whether its in focus or not.

Yep it will!