What’s Your Preference?

Btdown · #1 (**permalink**) 09-02-2011, 02:42 AM

A few weeks ago I bought a new Nikon 70-200mm f2.8 and have been using it with my Nikon D5100. I've begun to notice a problem where sometimes I'll press the shutter button and the lens does nothing...No autofocus...nothing..Just sits there. If I turn the camera off and on, it will work...for a while then do it again. Sometimes it does it right away, and sometimes not for a while. Unfortunately, it only does it when I'm doing real shooting instead of goofing off at home. I've tried to seat/unseat the lens, but I dont see any measurable effect in the frequency of the occurrences. Anyone run into this?
Thanks,
BT

3bayjunkie · #2 (**permalink**) 09-02-2011, 02:45 AM

Make sure you have AF on on the lens and on the camrea body. If it is only on on the body it could damage its AF motor. Although I don't believe the Nikon D5100 has the internal AF motor which is why I didn't buy it... Umm yeah. I guess I don't know. try focusing with it on M for a while then switch it back to AF I guess. That is what i would do to see if anything happends.

JFSanders · #3 (**permalink**) 09-02-2011, 02:49 AM

I haven't run into this but, when you have the problem can you still see lens information displayed such as focal length and aperture? If not then it will be related to the connections from the body to the lens. Does using another lens result in the same type of malf? If not then it would lead away from the pin connections and toward the focus motor in the lens. Try switching the M/MA switch back and forth a couple of times and make sure it is completely switched and not hanging in between. I suspect it is coming from the way you hold the lens and camera while shooting and your hand is moving the switch a little.

Jim

Doug Sundseth · #4 (**permalink**) 09-02-2011, 03:59 AM

Is there any chance you are trying to focus inside the minimum focus distance for the lens (around 4 - 5' for this lens, if my sources are reliable)? When I've switched from shorter to longer lenses in the past (especially right after buying a new longer lens), I have occasionally had a problem much like this. After turning off the camera, it worked fine, but that was caused by my moving the camera while it was off to a position farther from the subject, not the act of turning the camera off and on.

SwissJon · #5 (**permalink**) 09-02-2011, 07:15 AM

The times I've had this, it's been because of dirty contacts.. Either in the camera or the lense.. Try rubbing a pencil eraser gently over the contacts (make sure it's clean and that no bits drop off inside) to clean them.

kirbinster · #6 (**permalink**) 09-02-2011, 12:05 PM

I believe that lens has a focus limitter switch, do you have that turned on by mistake?

joyce30 · #7 (**permalink**) 09-02-2011, 12:13 PM

You have bought it just few weeks ago. Its better consult the service center. You do not need pay even a single penny because it is under warranty.

Btdown · #8 (**permalink**) 09-02-2011, 03:40 PM

Thanks for the tips...It will take me some time to work through the suggestions. The lens is an AF-S so the motor is there. I did take into consideration the minimum focus length, and moved the switch infinity switch back and forth, as well as the auto/manual switch. I'll try holding it differently and cleaning off contacts, but both camera and lens are basically brand new. It does not do this with other lenses.

This weekend, I've been asked to photograph some firearms that are going to be sold, so we'll see if it still occurs.

I really thank everyone thats tried to help here. I hope its ultimately operator error and not something wrong with the lens.

Thanks,