Auto focus on my SLR doesn't work

if other auto-focus lenses work, then it is likely that this particular lens has a defect I suggest you send it in to Nikon for servicing

At longer focal lengths, when the aperture is smaller, and in low light, many A/F zoom lenses struggle. Is it OK outdoors in daylight ? If so, lens is OK.

Hi there!

I experienced the exact same problem with my 100-300mm lens and I was never able to get it to work correctly again. In fact, attempting to use it further seemed to exacerbate the problem.

The further you zoom, the wider the aperture opens allowing more light for the camera to focus properly. If the aperture mechanism is damaged, the auto-focus process may not work as it should; which would explain why the auto-focus feature works only when at 18mm.

Regardless, I strongly recommend you discontinue use of the lens until a professional technician can examine the lens and figure out what's going on. I'm sure you can contact the manufacturer to open a support case or you can find a camera store that offers repair services.

I hope this helps!

Hi - I own this lens and it manually focuses at all focal lengths (hard to see at 18mm unless your subject is extremly close). You may need to get the lens checked. BTW - Mine was set as follows when I checked for you:

• D80 was "on"
• M/A
• VR = Off
• Normal (not Active)

Hope this helps!

google its user manual

changing lens from stock might be the issue
or 8 years auto focus sensor may be stuffed

please do a firmware upgrade

tell us what happened

Hello,

I don't own a K10D, but I do own a K100D which I have successfully used both manual focus & auto-focus lenses from my old Pentax stash!

1) If it is a manual focus lens, you need to turn off Autofocus on the body of your K10D. On my K100D, there is a switch on the side of the lens mount that says [-MF or -AF]. "-MF" is manual focus mode & "-AF" is autofocus mode. Since your lens doesn't have autofocus capability, turn it to the "-MF" mode.

Also . . . When I press "Menu" and go to "Custom Setting", I change two settings . . .

1) I change "Using aperture ring" to "Permitted". This allows you to use manual lenses (M lenses) that do not have an auto(exposure) setting, and also lets you use Auto lenses (A, KA, KA2, FA, etc.) in either the Auto or manual aperture setting modes.

2) I change "Fl with S lens used" so that even with a manual focus lens, although I don't have autofocus capability, my K100D beeps and shows a little red square in the viewfinder when I have successfully focused manually!

The K10D should have the same options.

This should get you up and running!

I have had a load of fun with my old lens on my new digital Pentax!

Take care & Happy Imaging!
Glen
:)

I doubt if there is anything you can do yourself. The manual focus may have debris under the ring or is in need of parts. I would leave this one to a tech.

Sorry, the mounts of Minolta manual focus lenses are different than their auto focus series. Sigma, Tokina and Tamron all make compatible zoom lenses to fit the Maxxum series cameras

Brush off any lose dirt from both the lens and bayonet mount and the autofocus drive shaft . If you are still not getting camera to auto focus your lenses have an expert look at the body : this is not an expensive problem to repair on these Pentaxes either a small mechanical problem or the connection to the pc board is bad. In either case only the front of the camera has to be dismantled ( +- 1 hour of labour to do the whole job ).