FM2 with Non-ai lenses

[codester80]

I thought I would share a little secret about the FM2 and non-ai lenses: they can be mounted. All the literature on the web says it's not possible because they will damage the aperture index ring. They will if you mount the lens with the aperture ring set at the maximum aperture. The trick is to set the aperture on the lens to the minimum and then mount it. The index ring is not interfered with when changing apertures on the lens as the rabbit ears (which catch on the index tab) never has to pass by the tab (except for lenses < f/2 when the ears reach the index tab). I've successfully mounted and used 24/H-28/H-50 lenses with no damage to the FM2. Of course YMMV. I'm guessing this is also true of the other bodies in the FM series but have not been able to try it.

 

[Godfrey]

Some pre-AI lenses will work and some won't. You have to be very careful to check and test or you'll end up breaking things.

I found it easier to have my pre-AI lenses modified for AI compatibility. John White does an excellent job, quickly, for not a lot of money:
http://aiconversions.com

Besides, then you get proper metering with your FM2 and other AI-and-later bodies.

G

 

[JP Owens]

Whether you can mount them or not, I've seen many non-ai lenses jammed by mounting them on the FM2 body. The FM does not have this problem, because the AI lever on the camera mount can be flipped up out of the way when mounting non-AI lenses.

I have never understood why Nikon made the AI lever fixed on the FM2. I suspect it was a marketing decision to force people to buy new lenses.

I remember having all my non-AI lenses converted by Nikon back in the 1970's. They charged $35 each for the conversion, I think.

 

[Dwig]

...

I have never understood why Nikon made the AI lever fixed on the FM2. I suspect it was a marketing decision to force people to buy new lenses...

Unlikely.

The FM2 coupling ring, being one piece of plastic, is vastly less expensive to make than the multipart metal ring on the FM/FE.

Also, the FM2 ring does a reasonably decent job of surviving the abuse of mounting a non-AI Nikkor, none of which will mount without stressing the coupling tab and conflict with the metering on an unabused body. Forcing a non-AI Nikkor onto an FM/FE/F3/EL2/FT2 will likely cause damage that requires replacement of bent components in order to restore reliable operation.

Many 3rd party non-AI lenses lack the overhanging lip on the f/stop ring that is present on all non-AI Nikkors. Most of these will mount successfully on AI bodies of all configurations. The original "tick mark" Auto-Nikkors will not mount on any AI body with the exception of the AI coupled F2 Photomics unless they have been modified. These won't fit any Nikkormat, even the non-AI Nikkormats, except the unmetered Nikkormat FS.

 

[rbsinto]

Why look for trouble?
Get an F or F2 beater body with a similarly beater meterless prism and then you'll never have a problem mounting whatever lens to it.

 

[sevo]

Whether you can mount them or not, I've seen many non-ai lenses jammed by mounting them on the FM2 body. The FM does not have this problem, because the AI lever on the camera mount can be flipped up out of the way when mounting non-AI lenses.

Jammed? Most (at least by time and type) won't fit and lock on at all, and those that can be forced on will bind and have to be removed with corresponding (moderate) force. But Non-AI lenses (at any rate original Nikkors) themselves are not at risk, the only thing that might get damaged is the AI coupler tab on the camera, which may bend or even break. But that will also happen whenever you forget to disengage the coupler tab on a FE (or other Nikon with a swing-out tab).

 

[ChrisPlatt]

I had an FM2n. The aperture ring on most pre-AI Nikkors did not clear the AI tab on the lens mount.
IMO either the FM or FE are a better choice if you plan to use older Nikon glass.

Chris

 

[kshapero]

Some pre-AI lenses will work and some won't. You have to be very careful to check and test or you'll end up breaking things. I found it easier to have my pre-AI lenses modified for AI compatibility. John White does an excellent job, quickly, for not a lot of money: http://aiconversions.com Besides, then you get proper metering with your FM2 and other AI-and-later bodies. G

I ditto this. Avoids all Non-ai problems.

 

[codester80]

It appears I got lucky with my original FM2 as I've been able to successfully mount and use my non-ai lenses without any damage to the camera. I switch between non-ai and ai lenses without a problem. Metering with non-ai works great using stop down.

I discovered the trick of mounting them was making sure the aperture was set to f/16 or greater when mounting. The problem, at least on my copy of the FM2, was the rabbit ears would clear the index tab. By setting the lens to f/16, the rabbit ears would clear the tab when the lens is rotated and locked onto the body. After that the rabbit ears only come near the index tab when setting apertures of f/2 or less.

Like I said, YMMV, and there are many variants of non-ai's out there. I did check to make sure the back of the lenses would clear the index tab before attempting to lock them on. The back of my non-ai's clear the tab my a hair. I did have an early 50 f/1.4 that had a thicker aperture ring and rubbed against the index tab. It was usable but risky.

I thought about getting my lenses converted but the cost and hassle isn't worth it considering the prices I paid for the lenses (two came free with bodies I wanted in a grab bag of gear). I also use a couple F3s with the non-ai lenses. No problems there with the flip down.

Has anyone ever hacked an FM2 by changing the aperture ring with that of an FM or FE to get the flip down tab?

 

[BillBingham2]

+1 for John or picking up a bargain priced F, F2 or F3.

B2 (;->

 

[Godfrey]

...
Has anyone ever hacked an FM2 by changing the aperture ring with that of an FM or FE to get the flip down tab?

I often thought I might do that, my FMs both had the earlier coupling ring with the flip-away lever, but in the end it was much more sensible to just have the lenses upgraded to AI compatibility when I'd gotten the FE2 and FM2n.

I still use a couple of those lenses—properly meter coupled for full aperture metering—with the Nikon F6 now. At $25 to convert them with a week's turnaround, it just makes sense to do the conversion.

G

 

[sevo]

Has anyone ever hacked an FM2 by changing the aperture ring with that of an FM or FE to get the flip down tab?

Must be possible - I once asked Nikon Service Mandic here in town for it, and he even quoted a very modest price for the work - but it was in the early nineties, when he had already run out of spare parts, and I was not willing to sacrifice my FE.

 

[ChrisPlatt]

I discovered the trick of mounting them was making sure the aperture was set to f/16 or greater when mounting. The problem, at least on my copy of the FM2, was the rabbit ears would clear the index tab. By setting the lens to f/16, the rabbit ears would clear the tab when the lens is rotated and locked onto the body. After that the rabbit ears only come near the index tab when setting apertures of f/2 or less.

One of us is confused. By "rabbit ears" do you mean the F meter coupling prong on the lens aperture ring?
These do not engage the AI tab. The lens AI coupling is at the rear edge of the lens aperture ring.
Many AI lenses do have the F coupling prong, for use with older Nikon metered bodies.

Depending on lens model the rear edge of the aperture ring of a pre-AI Nikkor lens
may be too close and bind with the AI coupling tab on the camera body lens mount.

Chris

 

[Dwig]

One of us is confused. By "rabbit ears" do you mean the F meter coupling prong on the lens aperture ring?
These do not engage the AI tab. The lens AI coupling is at the rear edge of the lens aperture ring. ...

Quite true, at least when dealing with an undamaged body.

Forcing a non-AI Nikkor onto an FM2/FE2 and leaving it on for awhile can often bend the plastic AI-tab. After such abuse, the tab can ride high enough to clear the f/stop ring's overhang but will still contact the prong. If this is what is happening with the OP's body then that body has been damaged and the bent AI tab will likely miss the AI ridge on AI lenses at times.

 

[weihsuan]

Has anyone ever hacked an FM2 by changing the aperture ring with that of an FM or FE to get the flip down tab?

Im very keen on this conversion to allow non-ai lenses to stay in their original condition. but have no idea how to do it. I do have a FM that I'm willing to do the swap, just not sure how possible it is.

Also, the prong of the Nikkormats be used as a cheaper option?

 

[peterm1]

In fact it is easy enough for anyone with only moderate skills to convert a non AI lens to AI for use on later cameras. All the info you need is on the internet and I have done it many times - it just requires a little research to understand where the filing must occur, the ability to remove the aperture ring (by undoing a few small screws) then some fairly basic filing skills with a small fine needle file to achieve it. The hardest part is reassembling the lens and getting the aperture mechanism to engage which can take a few tries till you understand how it is done. (Hint most lenses require you to have the lens focused to the nearest focus point - i.e. with the lens extended to its maximum length). It is occasionally (nowadays very occasionally) possible to find original Nikon AI conversion "kits" for lenses which consist of an aperture indexed ring for a specific lens. A few years back I bought a couple myself for lenses I owned. These kits allow you to convert a lens to AI then back again by remounting the original ring. A website of Nikkor lenses lists the kit number required for each lens variant (there are lots). Yhey are nice if you cam get them- but not strictly necessary.

In this way it is possible to pick up inexpensive but high quality lenses and continue to use them on pretty well any Nikon camera - I still use native non AI lenses thus converted, on my D700. They give excellent results with only minor issues from the earlier lens coating in some adverse lighting conditions. While some might have a philosophical objection to "mutilating" a lens in this way, if it is done sensitively and carefully I do not personally see the issue unless perhaps you have some extremely rare variant of a lens that collectors might want - in which case it would be wiser to sell it and buy something more common instead.

I am very careful about mounting an unconverted non AI lens on a later camera body. I did once, absent mindedly mount a 105mm f2.5 Nikkor on a late body and removed it without damage but put that down to dumb luck on my part. I later AI converted that lens which was in pristine condition and picked up for under $100 due to it being non AI (compared to double this for an AI version). I still use it. Other lenses I have converted include a 28mm f3.5, a 50mm f3, a 105mm f4 (micro), a 135mm f2.8, a 50mm f2.8 a 200mm f4 and others.

 

[jarski]

+1 for John or picking up a bargain priced F, F2 or F3.

B2 (;->

least after following up european used markets for years, haven't seen one single bargain F - F3 yet. starting price has been around 150 euros, and often well above that, which for me is not a bargain.

 

[sevo]

least after following up european used markets for years, haven't seen one single bargain F - F3 yet. starting price has been around 150 euros, and often well above that, which for me is not a bargain.

Several have sold on ebay for 80-100€ recently. If you include kits where the value of the rest brings the camera below a hundred, there would be even more.

And then there are camera fairs - where ugly, but working cameras tend to be sold for less than cameras of questionable function on ebay....

 

[jarski]

Several have sold on ebay for 80-100€ recently. ...

noticed this only now, and went to check for closed auctions in ebay.de. while there were couple examples of such (didn't check condition), would not call it several. most seem to go around 150 euros and above.

 

[Pete B]

I filed down my pre ais aperture rings to enable them to fit my FM3a. Some might say it sacrilegious, but at least they're getting used now.
Pete