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View Full Version : Help: autofocus only at f22 on D100?



photosean
09-22-2005, 11:10 PM
Hello everyone,

I'm new to this forum and have a question regarding my new (used) D100. I seem to only be able to use autofocus when my lens is set at f22 in any camera mode. When I go to any other f-stop the autofocus stops working. I'm sure there is a simple solution I'm just overlooking but I've gone through the manual and can't figure it out. I hope the problem isn't because I bought a used lemon. I'd appreciate any input.

Thanks,

Sean

Ant
09-23-2005, 01:49 AM
Are you talking about setting the aperture on the camera or on the lens itself via the aperture ring?

K1W1
09-23-2005, 06:50 AM
And information about what lens you are using would probably also be useful.

D70FAN
09-23-2005, 07:37 AM
Hello everyone,

I'm new to this forum and have a question regarding my new (used) D100. I seem to only be able to use autofocus when my lens is set at f22 in any camera mode. When I go to any other f-stop the autofocus stops working. I'm sure there is a simple solution I'm just overlooking but I've gone through the manual and can't figure it out. I hope the problem isn't because I bought a used lemon. I'd appreciate any input.

Thanks,

Sean

Not to worry. You are using a lens with manual aperture ring (like a 50mm f1.8 and etc.). These lenses were designed to be backward compatible to manual focus cameras. Your AF camera controls the aperture from the camera, and needs for the lens to be completely stopped down (f22 in this case) to opperate in AF mode. The f22 marking should be in red/orange (indicating the AF setting) and there should be a lock switch to prevent you from accidentally turning the aperture ring.

goletitout
11-04-2005, 09:26 AM
Nice response George. Iīm also a DSRL beginner and havenīt yet received the D50 Iīve ordered (thatīs why I cannot try the autofocus issues in the second paragraph at the moment). Iīm just too curious before I get the cam :).

Iīve already received my Nikkor 50mm F1.8 prime lens.
As you said, I have to keep the aperture setting at F22 and lock it, so far so good.

But what about that second ring on the lens, I mean the manual focus ring.
Which setting do I have to choose on the manual focus ring in order to have the lens work properly with my autofocus D50 ? Do I have to set in on "infinity" or what else ?
And : Does the autofocus of the cam actually cause the focus ring to rotate while focusing (so that it would make no difference how you rotate the ring before you start the cam)?