Ai conversion

[coyote]

Hi again
I was given a Nikkor 105mm f2.5 non ai lens and was reading that they could be converted to fit my fuji, does anybody in Aus sell the modified appeture ring or do I have to send it os for conversion. From what i read it costs about $35us for the mod plus shipping, would much easier if i could get it done here
Adian

[mongo]

Hi Coyote,
Mongo has modified many Ai lenses himself very successfully and very easily. It does not take too much time or skill and no additional parts – just a very fine file, tiny Phillips-head screw driver, soldering iron (for heat only purposes) and an accurate eye mixed with enthusiasm and patience.

Indeed, Mongo has the very lens you mention and performed an Ai conversion on it years ago and still uses it very happily today.

Now, all of the above is prefaced on the understanding that it is going onto a Nikon camera. When you say Fuji, do you mean a Fuji pro S1 to S5 models (which were meant to use Nikon lenses) or do you mean some other type of Fuji ????

The above process will still work if it is one of the Fuji pro series mentioned above but not otherwise.

[geck]

There is also a place in the US which sells the AI adaptor - basically the base plate of the lens. I think you need a lens serial number or something to order it, but it is a Nikon original part and as such doesn't devalue your lenses. That may not be necessarily important, but the fact that it would be the right part made for the lens gives it two big thumbs up in my book. I think they go for around $US20 each, but I'll try to find the link...

[coyote]

hi Guys
Mongo I have a fuji S2pro and would have a go if I knew where to file from and to, would save money and time

geck I have seen the sites that you mentioned and even found the number for the appeture ring (no 39) but they all say they dont have it anymore and nikon dosent stop producing them years ago
adrian

[mongo]

Another option would be to find and old disused f2.5 nikkor lens and take the ring off that. However, you will not find one and as far as Mongo is aware, that lens is virtually the only f2.5 lens Nikon ever made. So, basically no chance unless you manage to find a a damaged and unused Ai or Ais model of that lens. Again , very very difficult.

The only way Mongo thinks you will ever use this lens on that camera is to go through the procedure Mongo first outlined above.

Mongo has attached a couple of pictures to illustrate but is NOT suggesting you try this. The ring which needs filing is soft aluminium and easy to do. It must be filed evenly for the full length of the area which is to be filed and at about 1mm below the main nickel mounting ring. The exact length and position of the area to be filed has to be precisely calculated and marked. You will otherwise not get an accurate light meter reading. The entire aluminium ring which is to be filed must first be removed from the lens and the old light meter coupling should also be removed by unscrewing the 2 small screws with keep it attached. Once done, the ring is reassembled onto the lens. The old meter coupling can be reattached or left off – it makes no difference.

Maybe this info has been enough to show you that it is doable (took Mongo about 40 minutes) but enough to show you that you should not try this unless you know all there is to know to do it properly. Sorry Mongo could not be more helpful this time.

Forgot to mention that non-CPU lenses will only work on Nikon/Fuji cameras that have in their “menu” the ability to “set” the parameters (i.e the focal length and , more importantly, the maximum “F” stop number for that lens) for “non CPU lenses”. Mongo’s old D200 has such a facility in its menu. You should check that your camera has this otherwise the lens will not work even if you manage to have it converted.