no autofocus when switch lenses nikon?

marmagi · Mar 19, 2012

Hello,

I have a nikon D7000 and very often when I change lens the autofocus doesnt work.

I do turn off the camera before switching lenses. It happens with any lens no lens in particular. What could it be? contacts seam clean

In order to make it work again I have to keep unlocking and lock the lens many times until it works

Please give me some advice

thanks

480sparky · Mar 19, 2012

Dirty contacts?

Forkie · Mar 19, 2012

480sparky said:
Dirty contacts?

This.

Try wiping them with a cotton bud.

Boyun · Mar 19, 2012

A AF switch is on the body. Some lenses have a AF switch and some lenses don't. You may have moved one of the switches by accident. Did you check?

zamanakhan · Mar 20, 2012

Boyun said:
A AF switch is on the body. Some lenses have a AF switch and some lenses don't. You may have moved one of the switches by accident. Did you check?

hmm never had this happen to me, are you still able to shoot in AF-S mode? usually in single servo mode it wont let you release the shutter (unless u changed it) if its not in focus. If for some reason the lens is in manual focus mode than the shutter would release. IF thats the case check the AF toggle on both camera and lens like boyun said. I've never had a problem with contacts but also check the contacts. If that fails then i am stumped.

marmagi · Mar 20, 2012

First of all, thanks to all of you trying to help me. I have few questions:

what is the difference between the AF switch in the nikon D7000 body and the AF switch on the lens?

to clean the contacts use a cotton bud with alcohol ?

and the strange thing is that not always happens, some times I do switch lenses and it works fine some other times it wont

thanks

Forkie · Mar 20, 2012

marmagi said:
First of all, thanks to all of you trying to help me. I have few questions:

what is the difference between the AF switch in the nikon D7000 body and the AF switch on the lens?

to clean the contacts use a cotton bud with alcohol ?

and the strange thing is that not always happens, some times I do switch lenses and it works fine some other times it wont

thanks

AF on the body is the focus mode i.e, continuous servo or single servo. The one on the lens determines whether the lens is focussed using the motor (auto) or by you twisting the focus ring (manual).

The fact that your problem happens intermittently could be simply because dirt is getting moved around the contacts when you attach and remove a lens - sometimes it covers the contacts, sometimes actually putting the lens on might move the dirt out of the way. I would try cleaning the contacts with a dry cotton bud first before using chemicals. The dirt may just need dislodging.

480sparky · Mar 20, 2012

marmagi said:
...............what is the difference between the AF switch in the nikon D7000 body and the AF switch on the lens?............

The switch on the lens only affects that particular lens. The switch on the camera body affects all AF lenses.

The camera body switch also retracts the mechanical connection used to transfer the AF motor in the body to the lens. It's not addressed in the D7000 manual, but it's on the lens mount, right next to the DOF button (No. 4, Page 4 of the manual). That's the connection that drives AF lenses which require a body motor to AutoFocus.

zamanakhan · Mar 20, 2012

480sparky said:
marmagi said:

...............what is the difference between the AF switch in the nikon D7000 body and the AF switch on the lens?............

Click to expand...

The switch on the lens only affects that particular lens. The switch on the camera body affects all AF lenses.

The camera body switch also retracts the mechanical connection used to transfer the AF motor in the body to the lens. It's not addressed in the D7000 manual, but it's on the lens mount, right next to the DOF button (No. 4, Page 4 of the manual). That's the connection that drives AF lenses which require a body motor to AutoFocus.

pretty much, its there because AF lenses (most) do not have a switch on them for manual focus, so you put it into manual focus using the on camera switch. Afs lenses have a switch on them, doesn't matter which one you use.