NikonGear'23

Gear Talk => Lens Talk => Topic started by: chris dees on November 12, 2015, 08:49:20

Title: Looking for a pre-AI coupling prong.
Post by: chris dees on November 12, 2015, 08:49:20
I bought a mint Nippon Kogaku Nikkor-H 85/1.8, but the coupling prong is missing.
Does somebody know where I can find these or have one hidden in a drawer and want to sell it to me (with screws)? I'm looking for the rounded one (without holes).
Thanks.
Title: Re: Looking for a pre-AI coupling prong.
Post by: Erik Lund on November 12, 2015, 08:57:33
I should have somethiing like that in one of my boxes...
Title: Re: Looking for a pre-AI coupling prong.
Post by: Øivind Tøien on November 12, 2015, 09:23:47
When I buy a used AIS or earlier lens, one of the first things I do is to remove the coupling prong. It has no function  for any camera of interest for me other than bringing the lens into a collectors state. (Yes, I have an original F2 photomic that couples to that prong, but it is honestly not used any more and I also have a better working AI compatible prism for it). The prong tends to get in the way when handling in a bag, getting hung up in the fabric. It also can scratch other lenses if there is inadequate padding between them. I leave the screws in for sealing though, although it is not a big deal if they are missing.
Title: Re: Looking for a pre-AI coupling prong.
Post by: chris dees on November 12, 2015, 09:25:21
I should have somethiing like that in one of my boxes...

Thanks Erik, that would be great!
Title: Re: Looking for a pre-AI coupling prong.
Post by: chris dees on November 12, 2015, 09:27:28
Thanks Erik, that would be great!

I know it's of no use for modern DSLR's, but I have a nice collection of these lenses and want to have them as compleet (and original) as possible. :)
Title: Re: Looking for a pre-AI coupling prong.
Post by: Øivind Tøien on November 12, 2015, 09:28:51
Nothing wrong with that.  :)
Title: Re: Looking for a pre-AI coupling prong.
Post by: Bjørn Rørslett on November 12, 2015, 09:33:39
I'll have a spare. Send me a PM if interested.
Title: Re: Looking for a pre-AI coupling prong.
Post by: Frank Fremerey on November 12, 2015, 11:06:04
Our local NPS has a box full of there as spare parts, mabe your's too?
Title: Re: Looking for a pre-AI coupling prong.
Post by: Akira on November 12, 2015, 12:14:02
I leave the screws in for sealing though, although it is not a big deal if they are missing.

Haven't you experienced stiff rotation problem of the aperture ring when you put the screws back into the thread of the aperture ring?  I have had the problem with my Ais 50/1.4.  When I had my local Nikon service to remove the prong, they used shorter black screws to fill the threads.  The aperture operated normally.
Title: Re: Looking for a pre-AI coupling prong.
Post by: Bjørn Rørslett on November 12, 2015, 12:25:10
A small metal file will sort any issue quickly. Or a Dremel ...

The shorter {black] screws are for fastening an old type prong ("rabbit ears") on a newer aperture ring which is thinner than an old one.
Title: Re: Looking for a pre-AI coupling prong.
Post by: Akira on November 12, 2015, 12:39:46
The shorter {black] screws are for fastening an old type prong ("rabbit ears") on a newer aperture ring which is thinner than an old one.

Is the black screw you are referring to a flathead one, or a phillips-head one?  The black one I saw was a phillips-head one.
Title: Re: Looking for a pre-AI coupling prong.
Post by: Øivind Tøien on November 12, 2015, 13:37:45
Haven't you experienced stiff rotation problem of the aperture ring when you put the screws back into the thread of the aperture ring?  I have had the problem with my Ais 50/1.4.  When I had my local Nikon service to remove the prong, they used shorter black screws to fill the threads.  The aperture operated normally.

I have not really had that problem, but then most of my lenses have the thinner prong with hole in it, and the metal in the aperture ring is fairly thick. Perhaps the problematic ones never got any screws?   :)
Title: Re: Looking for a pre-AI coupling prong.
Post by: Akira on November 12, 2015, 14:14:28
Øivind, thanks.

I never removed the prong by myself except for that on the Ais 50/1.4.  So, the stiff aperture ring problem might be only for this particular lens...
Title: Re: Looking for a pre-AI coupling prong.
Post by: simsurace on November 12, 2015, 22:22:03
I removed the prongs on my manual Nikkors and put the screws back. I didn't notice any stiffness. But I'd like to keep the prongs should I ever have to sell these wonderful lenses (I hope not) :)
Title: Re: Looking for a pre-AI coupling prong.
Post by: Roland Vink on November 13, 2015, 00:44:49
With some lenses, when you remove the prong and replace the screws, the screws are too long and contact the surface inside the aperture ring. If it barely touches there will be increased and uneven resistance on the aperture ring, but more likely the ring will lock up completely. In this case either remove the screws, or shorten them, or source some of the short black screws that Akira mentioned (these screws seem specific for lenses with the prong removed, they are not from old pre-AI lenses)