Early Nikkor: DIY hack to AI?

[johannielscom]

Hi,

was wondering if anybody has hacked a Pre-AI Nikkor lens to AI themselves?

Should be a pretty simple hack with a Dremel, right?

I'm looking for directions to do this myself on my pre-AI Nikkor 1.4/58mm and 2.5/105mm and all info on how to proceed is welcome!

 

[ferider]

Yes, I've done my Nikkor-S 55/1.2. The hardest part on some lenses is to get the screws of the mount out - as long as the bayonet mount has screws (my 55 did).

If you send Brian an email, he can teach you how to modify very early lenses without screws in the bayonet mount. People do it sometimes with a dremel, other times I have seen little metal brackets attached to the aperture ring.

 

[DNG]

The ridges are higher than the N-Ai mount..
and you will need to know how long the long ridge, and the start and stop place, to key the Max f/stop

I think.. You may still find Ai kits out there in cyber land

 

[yanchep_mike]

Yes, done it not very difficult have a look here : http://www.chr-breitkopf.de/photo/aiconv.en.html#ai_pos

 

[VinceC]

I've done it to inexpensive lenses with just a file. The key is to use an AI'd lens for reference that has the same maximum aperture. You have to be fairly precise on where you start the notch, since that will affect the maximum aperture setting on the camera's internal light meter.

 

[kxl]

I've never done it personally; I sent mine to John White at aiconversions.com instead.

Here's another site that steps through the conversion process:

http://www.zi.ku.dk/personal/lhhansen/photo/repair/aimod/aimod.htm

 

[johannielscom]

Sweet.

Thank you fellows!

I got on board of the FX train earlier today, got myself a D600 to power my wedding shoots😎 and I will (for now) primarily shoot MF lenses with it until I can afford an AF lens.

Lenses used will be the Nikkors 1.4/58mm and 2.5/105mm, Tamron Adaptalls 24-48mm and 35-80mm. These lenses have great low contrast when opened up, and are impressively sharp when stopped down!

 

[johannielscom]

Yes, I've done my Nikkor-S 55/1.2. The hardest part on some lenses is to get the screws of the mount out - as long as the bayonet mount has screws (my 55 did).

If you send Brian an email, he can teach you how to modify very early lenses without screws in the bayonet mount. People do it sometimes with a dremel, other times I have seen little metal brackets attached to the aperture ring.

Just my luck, my two pre-AI lenses both are screwless...

 

[Highway 61]

Yes, I've done my Nikkor-S 55/1.2. The hardest part on some lenses is to get the screws of the mount out - as long as the bayonet mount has screws (my 55 did).

Those screws may sometimes be hard to remove because they were glued at the factory. The trick is to heat them with a soldering iron for a while, then they will unscrew with no problem if you use a good screwdriver with an excellent head and a large grip.

Johann : just check if something you need might not remain in stock by clicking here.

 

[sevo]

Those screws may sometimes be hard to remove because they were glued at the factory. The trick is to heat them with a soldering iron for a while, then they will unscrew with no problem if you use a good screwdriver with an excellent head and a large grip.

... unless some fool fouled up the head earlier on. Beware when buying used Nikkors - check the mount screw heads (usually just one or two of them were glue-secured), as many have been wasted in a futile attempt to force open the lens...

 

[Jan Pedersen]

Be careful with that 58 1.4 i have one too and wanted to convert it to Ai for my D800 but read somewhere that the 58mm can damage the mirror.
I never changed mine but if someone does this and find that it works on a D600/D800 then i will make the change too.

 

[ferider]

Just my luck, my two pre-AI lenses both are screwless...

It can still be done with a Dremel, Johan, see for example 230941936661@ebay.

Like I said, send Brian an email, I'm sure he'll respond (very few people here have ever done this with this type of mount).

Roland.

 

[Contarama]

John White's website explains some of the different types of conversions. Not all non Ai lenses are created equal. Different ones require different procedures during the conversion process.

You may also try picking up a factory Ai version of your lens if you can find one dirt cheap and then cannibalize it for the factory ring. I have done this with a 105/2.5.

 

[johannielscom]

Be careful with that 58 1.4 i have one too and wanted to convert it to Ai for my D800 but read somewhere that the 58mm can damage the mirror.
I never changed mine but if someone does this and find that it works on a D600/D800 then i will make the change too.

Interesting information, Jan! I'll make sure to find out about this. Sure would be sad if the lens would not go onto my new camera, I found it to be impressive on my little D3100 already, and was looking forward to seeing it in action on FX!


@ Roland, I'll contact Brian tomorrow and ask him directions on how to proceed, thanks!

 

[johannielscom]

Be careful with that 58 1.4 i have one too and wanted to convert it to Ai for my D800 but read somewhere that the 58mm can damage the mirror.
I never changed mine but if someone does this and find that it works on a D600/D800 then i will make the change too.

Hi Jan,

After browsing just a bit I found a Ken Rockwell link tonight that does not mention the risk of lens and mirror colliding at all, and also shows a sample shot, taken with the 1.4/58mm and a D800E.

Seems there is no risk when using the lens on a modern-day FX DSLR! 😀


http://kenrockwell.com/nikon/58mm-f14.htm

 

[Jan Pedersen]

Hi Johan,
That is good news, thank you for checking that.
I don't remember where i read the warning and it is obviously also incorrect.

 

[Landshark]

I always use a file. but the aperture ring needs to come off.
I personally think the Dremel to be more hazardous if it were to slip and is also too aggressive.

 

[johannielscom]

There, I did it.

Found a tutorial on YouTube on how to remove the optical block from the 1.4/58mm. I stripped it down as much as I could, then taped it all up to make sure no filing residue would get into the helicoid.

Cleaned the exterior parts as well, lukewarm water and a dishwashing detergent. Lubed it where necessary and cleaned out excessive grease and crud.

Focuses like a charm now and spot-on too, meters as it should!

Later this week I will try my luck on the 2.5/105mm too😎

 

[Peter_Jones]

A bit late to the party, but I did this with a 55/1.2 - the screws were a pain, but once the aperture ring was off, it was just a case of careful filing with a fine swiss file, keeping the cutout as flat as possible. I erred on the side of caution, and the lens metered at 1.4 first attempt, but it's easier to remove metal here than it is to add it 🙂

 

[johannielscom]

My new Nikon D600 with my freshly AI'd 1.4/58mm Nikkor-S, a 1961-made lens. How cool is that!?​