Author Topic: Ai conversion of a Nikkor-P 105mm f/2.5  (Read 15155 times)

MFloyd

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Ai conversion of a Nikkor-P 105mm f/2.5
« on: June 05, 2016, 11:43:57 »
Who could help me in converting this lens I bought new more than 40 years ago ? I had two 105mm lenses, one which has been converted, and this one. Preferably I would like to forward it to somebody who would take care of the process, and why not, chip it also. Against a reasonable remuneration off course. I know that the #39 conversion kit appears not to be available anymore.  I have also a small spot of fungus on one of the rear lenses, but without a visible impact.


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richardHaw

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #1 on: June 05, 2016, 16:11:38 »
what a lovely lens. converting it to Ai is not really that difficult. :o :o :o
if you do not intend to use it for bodies lower than the D7200, then you can follow my guide at richardhaw.com, all you need is a file and some patience. If you have a drill press then you can mill it properly ::)
Thankfully for this lens, the rear element can be accessed easily. ::)
if this is the only lens that you intend to have these done then you can send it to a technician. if you have more of them then it is probably best that you learn how to do it yourself  8) That is a very sell lens, I like it a lot. I own 4 105mm's 2.5

MFloyd

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #2 on: June 05, 2016, 17:04:34 »
Thank you Richard. I'll have a look. 😊
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Matthew Currie

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #3 on: June 05, 2016, 19:23:32 »
I have a 105 of almost exactly the same age as that one, and it's a long time favorite.  I converted mine long ago, and it was not terribly hard to do, using an approach similar to Richard Haw's.  I did the further milling required to make the lens 100 percent compatible with some early AF cameras that have a min. aperture switch that pushes sideways (N60, Fuji S1, etc.), but for any camera that has an AI follower this is not needed. 

One thing worth noting, though, is that there is a little spring attached to the aperture ring, and it's a little tricky to disengage and re-engage that spring when you take the aperture ring off.  Not every old lens has this, but the 105 does.  If you know in advance that it's there it can be done without huge fuss, but if not, you can stretch it on removal. It takes a bit of fiddling to re-hook it.  If you're not comfortable with this, I'd suggest sending it out. 

Last I knew Vermont Camera Works (in Pittsford, Vermont) did the conversion for a reasonably small fee.  I don't know if they do the min aperture part, but they probably would if you need it.  Dave, the boss there, recently de-fungused my old 400/5.6 lens (which he said was wickedly complicated inside), so I know they do that too.  Might be worth an email.

p.s. I would add that newer low-end bodies, such as the D3xxx and 5xxx series, though they have a minimum aperture switch, are not harmed, because that switch is now pushed down instead of sideways.  My D3200 will take nearly any Nikon lens of any age, converted or not.

MFloyd

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #4 on: June 05, 2016, 21:21:34 »
Matthew, thank you for your kind post.  I will have a look at Camera Works in Vermont. I have four FX bodies left: F2As, F4, D610 and a D5.
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richardHaw

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #5 on: June 06, 2016, 04:29:57 »
Oh, yeah. that little spring is annoying. many older Nikkors have it connected like this.  :o :o :o

MFloyd

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #6 on: June 07, 2016, 22:35:30 »
It will be Erik Lund who will do the AI conversion, and equip the lens with one of Bjørn's chips. Thank you both, as well as the others who gave me guidance. 😎
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MFloyd

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #7 on: June 23, 2016, 22:32:06 »
The lens has been delivered to Erik's place, and Bjørn has already sent the chip. Houraah
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Hugh_3170

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #8 on: June 24, 2016, 02:14:50 »
Erik will add a great deal of convenience to this desireable old timer with not one but two levels of "technology refresh".

Well worth doing.  Enjoy!
Hugh Gunn

MFloyd

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #9 on: June 24, 2016, 08:28:00 »
On return I could then show off to the local NPS dealer who happens to be a friend and a rowing mate for over ten years.
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chris dees

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #10 on: June 24, 2016, 09:07:40 »
And this is how it will look. ;D
Although this a the P.C version from 1973.
Chris Dees

Erik Lund

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #11 on: July 04, 2016, 20:37:02 »
Not quite Chris, you have an original Ai ring on ;)

Her is how it looks, cleaned and lubed as well

Erik Lund

MFloyd

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #12 on: July 04, 2016, 20:47:49 »
Yahoooo!!! 😜🍾👻
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Akira

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #13 on: July 04, 2016, 20:50:51 »
Awesome!  How could you keep the rabbit ears attached to the trimmed aperture ring with the screw holes and the screws altogether?!
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Bjørn Rørslett

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Re: Ai conversion of a Nikkor-P 105mm f/2.5
« Reply #14 on: July 04, 2016, 21:09:05 »
This is Erik, remember ... Another immaculately completed job.