• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Nikon AI conversion

Recent Classifieds

Forum statistics

Threads
204,276
Messages
2,866,541
Members
102,207
Latest member
gustavocf
Recent bookmarks
0
You _do_ need to AI-convert the lens for the prosumer FM2, FE2, and FM3a as the body's aperture follower-tab does not flip down on those cameras. If you try to mount a non-AI lens, it will likely damage the plastic aperture follower-tab, and may even jam the lens on the mount. The older F3, F4, FM, and FE all had metal, flip-down follower-tabs, so can directly mount a non-AI lens (as long as you remember to flip the tap down!). The F5 and F6 did not come with flip down tabs, but Nikon reportedly offered a modification to install a one, though I personally have never seen such a modded body in the flesh.

Oh, I didn’t realize that they got rid of the flip up lever on those. I found it a very nice feature on the F3 and FM.
 
After going to my local photo dealer (Foto LAmbertine) in Cologne, who has fantastic customer service, by the way, I've decided to let them send it to Nikon for the AI conversion. Nikon apparently still does it and quoted $150. My question now is: What can I expect from Nikon for that price? Still a milled aperture ring, or a proper aperture ring replacement, which otherwise is no longer available? Did anyone here had Nikon do it, and what did you get?
 
Ralph let us know which lenses and what they send back.
 
After going to my local photo dealer (Foto LAmbertine) in Cologne, who has fantastic customer service, by the way, I've decided to let them send it to Nikon for the AI conversion. Nikon apparently still does it and quoted $150. My question now is: What can I expect from Nikon for that price? Still a milled aperture ring, or a proper aperture ring replacement, which otherwise is no longer available? Did anyone here had Nikon do it, and what did you get?

Wow, that is super surprising! At least in Canada, Nikon Service won't touch even moderately old lenses with a 10ft pole. I asked about getting my 2005 copy of the 28/1.4D lens repaired and they informed me that it was no longer supported (the infamous A/M control ring had cracked, and I even had the replacement part, so all I wanted was for them to install it). If this is your non-AI 105/2.5, I would be curious to see what they do for you.
 
I don't think that would work. When prices got low enough and there were different Nikkors to choose from, I just got both. When using a pre-AI lens with a Nikkormat FT3, I just flip up the AI tab. Using an AI lens with a prong on a Nikkormat FT2 is no problem. In the past, John White did some conversions for me. I have enough different Nikon film cameras that I don't think I would bother getting any more Nikkors converted. My 28/2 Nikkor is a 'K' model but I have used it in stop-down meteting mode with a Nikkormat FT3 successfully.

The metering in my FT3 is erratic. I think it's the exposure circuits or slider potentiometer. Any suggestions?
 
Wow, that is super surprising! At least in Canada, Nikon Service won't touch even moderately old lenses with a 10ft pole. I asked about getting my 2005 copy of the 28/1.4D lens repaired and they informed me that it was no longer supported (the infamous A/M control ring had cracked, and I even had the replacement part, so all I wanted was for them to install it). If this is your non-AI 105/2.5, I would be curious to see what they do for you.

In Germany Nikon has a central facility at their main address, Nikon GmbH, Tiefenbroicher Weg 25, Düsseldorf but also use a number of subsidiaries to provide a service-network. Some of the subsidiaries are in business for many decades and may have the parts and knowledgable staff to provide service for older gear. But providing this service is at the descretion of the actual facility.
 
Last edited:
I will post the result.

I called and sked. The reply was:no more conversion rings available." So, Nikon too takes off theexisting aperture ring and mills it down. that was to be expected, but at least I trust, they have enough experience not to mess up thelens. My other milling srvice wasn't too sure that the screws of the aperture ring can be taken out without problems. God forbid.
 
No, you can’t.

So, I decided to send the lens to Nikon in Düsseldorf for an AI conversion for which they quoted €150; not cheap but what the heck at least done right, presumably.
The lens came back today. Atfirst look:Great; no machining off the existing aperture ring. No, a brand new metal aperture ring all fitting my D800 perfectly and easily mounts. But once mounted, the LCD on the camera always shows an f/stop higher than what I set on the aperture ring evon though I enterered the correct CPU lens dta(105/2.5). I'm wondering if they installed the wrong kit ring or had it machined incorrectly. Tomorrow, I will try to trick the camera by entering compensating CPU lens data. I just need to be sure that what I set on the aperture ring is the actual f/stop for my flash exposures to be correct.
 
So, I decided to send the lens to Nikon in Düsseldorf for an AI conversion for which they quoted €150; not cheap but what the heck at least done right, presumably.
The lens came back today. Atfirst look:Great; no machining off the existing aperture ring. No, a brand new metal aperture ring all fitting my D800 perfectly and easily mounts. But once mounted, the LCD on the camera always shows an f/stop higher than what I set on the aperture ring evon though I enterered the correct CPU lens dta(105/2.5). I'm wondering if they installed the wrong kit ring or had it machined incorrectly. Tomorrow, I will try to trick the camera by entering compensating CPU lens data. I just need to be sure that what I set on the aperture ring is the actual f/stop for my flash exposures to be correct.

I found the error. I did enter the CPU data correctly but I didn't save it correctly. After fixing that everthing works as expected. Nikon did a good job with the conversion. Iadded a pic to show you what a modern factory conversion looks like Note: the new metal aperture ring and the added aperture index tab; quite different from maching an existing plastic aperture ring
 

Attachments

  • FactoryAI.jpg
    FactoryAI.jpg
    310.7 KB · Views: 44
I found the error. I did enter the CPU data correctly but I didn't save it correctly. After fixing that everthing works as expected. Nikon did a good job with the conversion. Iadded a pic to show you what a modern factory conversion looks like Note: the new metal aperture ring and the added aperture index tab; quite different from maching an existing plastic aperture ring

Wow, it looks like they machined the whole ring, then added a "stop" to engage the AI ring on the camera.
Clever..I've never seen that before.
 
FT-3 always had "erratic" needle, even when it was new, I call it jumpy. Just be a little patient and it will settle down. That meter has it's limitation but I never had accuracy issues with it, with slide or negative film. Great camera!

Yes, that is a known issue.
A great bargaining chip.
Great camera, very under-appreciated and under-valued.
 
I still don't know the reason for Ralph to buy the pre-AI lens instead of the AI version? is the Pre-AI version better in any way?
 
I still don't know the reason for Ralph to buy the pre-AI lens instead of the AI version? is the Pre-AI version better in any way?

Chan, it was just a matter of a good AI version not being available at the time. Also, I think pre-AIs are Sonnars, and most AIs are Xenotars; the change was made sometime in the 1970s, but both are excellent. After this experience, I'll never buy a non-AI again
 
Chan, it was just a matter of a good AI version not being available at the time. Also, I think pre-AIs are Sonnars, and most AIs are Xenotars; the change was made sometime in the 1970s, but both are excellent. After this experience, I'll never buy a non-AI again
The switch from Sonnar to Xenotar occurred in 1971 solidly in the pre-AI era. Sonnar 105/2.5 lenses have the silver snout and quite narrow rear element. The Xenotar design was maintained throughout all AI and AiS versions. The last Sonnars in serial #234140 - 286451 could be factory AI converted and you do frequently find these silver snout lenses with a nice OEM AI aperture ring. This late Sonnar with factory AI is the version I own, and it was actually cheaper than an unconverted lens — no longer a collector condition lens I guess!
 
The switch from Sonnar to Xenotar occurred in 1971 solidly in the pre-AI era. Sonnar 105/2.5 lenses have the silver snout and quite narrow rear element. The Xenotar design was maintained throughout all AI and AiS versions. The last Sonnars in serial #234140 - 286451 could be factory AI converted and you do frequently find these silver snout lenses with a nice OEM AI aperture ring. This late Sonnar with factory AI is the version I own, and it was actually cheaper than an unconverted lens — no longer a collector condition lens I guess!

Mine is definitely a Xenotar, and I love its rendering. I mostly use it f/2.5-5.6.
 
Mine is definitely a Xenotar, and I love its rendering. I mostly use it f/2.5-5.6.

Until I bought my AI'ed Sonnar last year, I only ever owned the Xenotar 105/2.5 (always an AiS version), and like you mostly shot wide-open or close to it, rarely stopping down past f/5.6: The background blur and subject isolation at wider apertures is very nice with this lens, and is pretty much why I would consider to use it over my “normal “ 24/2. The Sonnar is reputed to have a more flattering portrait rendering, where "flattering" often means soft/dreamy when it comes to head-shots: You don't want clinical detail for a portrait. I found out the hard way that sharper ain't better when I traded my 105/2.5 for a Micro-Nikkor 105/2.8, and suddenly found my head-shots were less satisfactory. Just sayin' that the reason some prefer the Sonnar is that it is a less sophisticated optical design where the uncorrected aberrations of an older design may actually contribute to a better "look" for some purposes. I do like my Sonnar, but after due consideration my AiS is still my goto 105 without a doubt.
 
Last edited:
I did my Ai conversion with a dremel. It's a bit ugly but works fine. I don't think I'd do it with a rare or valuable lens but 105/2.5s are a dime a dozen.
 
I did my Ai conversion with a dremel. It's a bit ugly but works fine. I don't think I'd do it with a rare or valuable lens but 105/2.5s are a dime a dozen.

that must be a very rare dime. a 105mm f/2.5 in clean, working condition goes for $200-300 unless you don't mind ugly, which I do.
 
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab Blue Moon Camera & Machine
Top Bottom