What is this? D600 F Mount

[MOREGONE]

Hello,

I have been having this weird clicking noise from my camera after taking off a lens and I was able to finally confirm where it is coming from.

It is the small tab thing in the picture. when a lens is put on it rotates counter clockwise (as facing the camera). When the lens is removed it sticks there, then eventually smacks back into place a moment later.

Any ideas? Is this serious?

My D90 doesn't have this and it seems to be guaranteed to happen if I mount my 50 1.8D on it. Doesn't happen every time I change the lens which is why it took me awhile to confirm where it came from.

 

[Derrel]

That is the Ai-coupling tab. It interfaces with the Ai-notch milled into the rear of the aperture ring on Ai- and Ai-S Nikon mount lenses. It's spring-loaded, and normally, it should SNAP! back into place pretty quickly and smartly when manually pushed in the direction of the arrow and then released, but I have an old Nikon FE-2 body where it got a bit sluggish and moved back reallllly slowly (the body was used a LOT for saltwater boat fishing back in the 1980's...).

Exactly "how far" that tab is moved when an Ai- or Ai-S type lens is mounted tells the light meter 1) what the maximum f/stop of the lens in use is and 2) what f/stop the lens is set to.

It's not really serious at all, unless you use Ai- or Ai-S type lenses and want 100% accurate and consistent light metering from that type of lens. Try moving it all the way counter-clockwise and letting it go a few dozen times, and see if it doesn't loosen up. With a CPU-equipped lens mounted, it's not even in operation

 

[MOREGONE]

Thanks Derrel,

If I move it manually it does snap right back. Something about the 50 1.8D makes it stick for some reason. I am not sure if it is the only lenses that makes it do that.

Glad that it is not super serious and as I buy newer lenses it will be less and less of an issue.

 

[Derrel]

I just wanted to add a little bit more info to clear up any possible confusion people might have: the Ai coupling tab system of camera/lens interface and communication was premiered with the Ai or Automatic aperture Indexing Nikon cameras and lenses that came out back beginning in 1977 or so. The same Ai ridge used on Ai-Nikkor and Ai-S Nikkor lenses is also on AF- and AF-D Nikkors, but since those autofocus lens lines use CPU contacts, the contacts on the lens and inside the newer cameras are the way the aperture information is conveyed between lens and body in most cases, on most bodies.

What I call "the Baby Nikon" models like the D3000-series, D5000-series, D40 series, and D60 model, do NOT HAVE the AI-coupling mechanism at the 1 o'clock position on the bodies. So, don't look for that little tab on those bodies...it's not there! The Baby Nikon models (and the D600 as well!) also lack the minimum aperture sensing pin, located at 7 o'clock. The LACK OF an AI coupling tab AND the lack of a minimum aperture sensing tab is the clever way that Nikon allowed the Baby Nikon models to accept basically ANY F-mount lens or accessory ever made [except very rare and highly-collectible "mirror-lockup-needed" invasive fisheyes from the 1960's]. The lack of those two mechanical interfaces means the Baby Nikons can accept really old, cheap, late 1950's, 1960's,and 1970's F-mount lenses without damaging the body. Of course, there's no metering and no flash control when using those oldies, but they do mount, bayonet on, lock into place, and the diaphragm control works!

On the D600, the Ai coupling tab could be damaged by mounting several different pre-AI Nikkor lenses that have "the fat style" aperture ring.

 

[MOREGONE]

Do you think this sounds like it could be a bent mount?

Sent my D600 in for service of the oil spots and they sent me a $333 bill for a bent mount.

This is the closest thing I can come to thinking about having an issue. I have zero complaints with the body aside from the spots.

"MOUNT CAMERA MOUNT BENT." thats all the bill says. Going to call in shortly just trying to get my ducks in a row

 

[wfooshee]

Bent mount would certainly be able to jam that sensor pin and make it not move freely. It would have been nice of them to notify you of the condition and give you an estimate, since that wasn't what you sent it in for......

That tab being present on my D7000 means I can use my legacy 85mm f:1.8 and get metered aperture-priority auto-exposure. The lens data is in the non-CPU lens menu, so it knows that all the way over is f:1.8, it reads the aperture correctly on all settings, and even records it in the EXIF data.

 

[18.percent.gary]

To me "camera mount" means the body mount aka the tripod mount on the bottom of the camera.

The flange on the camera body that receives the lens is usually referred to as the "lens mount".

Definitely give them a call with your Repair Order number handy to find out what the actual problem was.