Issue with Photomic TN finder

[mgb74]

On a new-to-me Nikon F with the Photomic TN finder, there is an issue with the pin on the finder that engages the prong on the lens. It is recessed into the finder so that it will not stay in position in the center of the prong when the aperature is at the extremes for the 50mm f1.4 lens (f16 and f1.4). In the 3 photos below, the first is how that pin should look and the 2nd and 3rd photos are how it does look.

Before I go back to the seller, I thought I'd check with the accumulated wisdom here to see if I'm missing something.

 

[benjiboy]

You are setting the lens at f 5.6 before trying to mount it and then setting the minimum and maximum aperture of the lens.

 

[Kino]

You are setting the lens at f 5.6 before trying to mount it and then setting the minimum and maximum aperture of the lens.

+1 I had the same confusion when I got my F with a TN finder.

 

[mgb74]

Yes on both - setting at 5.6 and "shuffle" back and forth. There should be some vertical "spring" in the pin to allow it to pop inside the prong and stay inside. On this finder, the pin is inset into that slot.

 

[Kino]

The mechanism may be sticky. Try cleaning the lever points with alchohol.

 

[mgb74]

A bit more information on the proximate cause. There is a curved bar in the finder that this pin rides upon. It moves the pin down at each end to compensate for the movement of the indexing prong.It In my case, it is not riding on the curved bar and therefore causing the pin to lose engagement. Whether due to something "sticky" or a mechanical issue, I don't know. As this is a very recent ebay purchase, I'm not going to open it up until I know I will keep it.

 

[mgb74]

It went back to the seller and I received a full refund. The seller felt there was nothing wrong with the finder; I question whether he really tried it through the full f-stop range. What I did not mention in my original post is that the shutter was also bad, exhibiting what I felt was significant shutter capping. He questioned my contention that the shutter was bad but, when I asked if he had done a film test, he was silent, This follows a common pattern of sellers listing items on ebay as "used" when they have no clue about the actual working condition

 

[MartinCrabtree]

The problem with online purchasing. Caveat Emptor.

 

[Horatio]

Glad you got a refund.