TC-1.4s and DSLRs - Request for Help

[Robert Camfield]

An unexpected snafu has come up with the TC-1.4B and 300 F4.5 ED-IF AIS. The TC-1.4B blocks the mirror from fully retracking (D600), at least apparently. This issue has just recently surfaced, and I'm unsure why. Any ideas?

In any event, I'm thinking of purchasing a modern TC-14E, providing it will work with dated Nikkor telephotos - AI and AIS.

Any advice and all comments welcome...Thanks, Robert   

[Birna Rørslett]

That shouldn't happen, so something is amiss with the components involved. Perhaps a photo of the TC and its rear end could give further clues? You are certain the stop screw on the TC is present?

The newer TC-14E.mk2 can easily be adapted to work with older lenses.

[Robert Camfield]

Birna,

Thank you for your message. Perhaps you could clarify the stop screw...just what might it be?

Thanks again, Robert

[Birna Rørslett]

Birna,

Thank you for your message. Perhaps you could clarify the stop screw...just what might it be?

Thanks again, Robert

180 degrees to the top of the lens when it is mounted. This is a small screw to prevent the lens to rotate too far in the camera's mount. You know it's engaged when you hear a small 'click' as the lens is mounted and twisted.

[Matthew Currie]

If a lens or adapter without that stop screw is over-rotated the wrong way its aperture lever can ride over the corresponding lever in the camera, and cannot be readily removed without bending something.  On film cameras it was possible to dis-entangle the levers from behind, but on digitals I'm not sure how it would be done without some damage or great inconvenience.

I mention this because if you've had such a mishap and had to use force to get the lens off, you should double check that the camera's lever is not bent.  That on the old F's was made of brass and easy to unbend, but I don't know about nowadays.

[Robert Camfield]

Mathew,
Birna,

Perhaps I have located the stop screw that you mention: a spring-loaded pin embedded in the lens mount on the camera body, located approximately 120 degrees clockwise from the top. The pin snaps out into a slot on the lens mount, as the lens is twisted counterclockwise while mounting to the camera body.

In any case, the TC-1.4B AIS appears to mount properly - not going beyond the stop. Also, various other AI/AIS lenses mount properly, and the camera stops lenses down to working apertures just fine. When TC-14B is in place on the camera body, I'm able to see the entire image scene through the viewfinder. However, in live view mode, with the mirror in the retracted position, the bottom 1/4 - 1/3 of the image along the bottom edge is blocked (blacked out), and photos are also blacked out along the bottom. The mirror is not fully retracted, I think, as it is hitting the metal "surround" that contains the rear element of the TC. I note that the TC-14B rear element extends into the camera body.

It's a mystery...The issue just came up - I've been using the TC with the 300mm for 3-4 years without difficulty.

Thank you for your comments and help - much appreciated, Robert   

[Matthew Currie]

While I doubt it has anything to do with your problem, the screw I was referring to was something else.  It's a tiny screw on the lens itself, which prevents the lens from rotating past the lock point and from being dismounted in reverse, as might well happen if you're used to other systems, which often operated in reverse from Nikon's.  The screw is tiny, and although it's rarely a problem, it can come out and there's the devil to pay if it does.  Here is a picture.  It's the tiny crosshead screw facing us - always at the far end of the bayonet, approximately 180 degrees from the top center point. I lost one once, and once also got a grand bargain on a used lens with that screw missing.  The first time I bent a lever, and the second (fortunately on film still) I disengaged it without damage from behind, but now check my lenses from time to time to make sure that screw is not falling out.

[Birna Rørslett]

As to the stop screw,  a judiciously added drop of Loctite is the final answer.

As to the TC-14B, we do need a close-up of the rear end of the TC to learn whether something is amiss. You aren't by any chance using a flash and have set the shutter speed too fast?

The TC-14B extends slightly into the camera throat, but by no means so far as to cause any contact with the reflex mirror. Just checked my own TC-14B to ensure this is the case.

[Birna Rørslett]

Robert: you located the AF "screw driver" shaft on the camera's mount. This is not the troublemaker here.

[Robert Camfield]

Birna,
Matthew,

Yes, I have found the stop scree located, as Birna indicates, at 180 degrees from the top – did not notice this before, never mind that I've used Nikkors for several decades. The TC-1.4B clicks in place properly.

And I agree: generally speaking, TCs do not appear to reach into the mirror box far enough to interfere with the operation of the mirror...indeed, it would constitute an egregious design flaw. Yet, the issue confronting this TC unit remains a mystery. Last night, I filed down the metal rim surrounding the rear element, to no avail - as expected.

I will take another look – stay tuned…and may trouble you with a photo though frankly I don’t wish to burden you further.

Also, I did not confuse the AF control located at approximately 7 o’clock with the spring-loaded pin – which gives off the “click” signaling a proper mount of lenses to camera body – located at approximately 4 o’clock.

Thanks again for your help…Robert