Converting M lens into LTM?

[rondal]

I would like to be able to use an M bayonet lens on an LTM body. Is it

possible to surgically remove the M bayonet from a lens and replace it

with a screw-mount, while still being guaranteed focusing accuracy?

Who is capable of doing this conversion?

[Bill Blackwell Images]

While this is a question better answered by DAG or some other Leica repair expert, I'm sure it could be done; but why would you want to do such a thing. IMO, M bodies are far better and more usable than any LTM body and you would be devaluing a lens in the process of spending money on the conversion.

 

There are plenty of LTM lenses available today, which again begs the question why you would want to downgrade a perfectly good M mount lens.

[leica ron]

I'm sure there are people out there who can do this but the cost would be prohibitive and may not even work properly.

 

Using an M lens is not possible with a screwmount. Apart from the bayonet/screw issue, the rear-element on some M-lenses comes back too far.

 

If you want modern optics in a screwmount the current way to go is with the latest Voigtlander designs. For example, the Nokton 50mm f1.5 has two aspheric surfaces and ED glass and costs around 400 USD.

[SolaresLarrave]

I read somewhere that while the LTM glass can be adapted to M-bodies, the opposite cannot be done, because you'd be shortening the distance between lens and film, and therefore render the combination camera & lens unusable.

 

If you want to use M lenses on an LTM, you'd be better served buying and using LTM-ready lenses from the CV line, or any other original LTM glass offered for sale all over the place.

[roger_michel]

sk grimes in RI will do the work for about $500. no problem. also, be advised that leica, several years ago, released the current 50 cron, 50 lux and 35 asph cron in LTM. i own the two crons in this form and use them regularly on all manner of LTM bodies (as well as on my M cameras with an adapter. only came thru in chrome. these come up on ebay and dealers may still have a few.

[leica ron]

These special edition lenses were made for the Japanese market and are not cheap !! Roger, you're a lucky man to own some of these beauties !!

[rondal]

Thanks for your responses.

 

I am planning to use a Leica M2, M4 or M4-2 as my primary body and a 40/2 M-Rokkor as my standard lens (whose FOV is allegedly a perfect match for those cameras' 35mm framelines).

 

The tricky part is that I would like to have a backup body, as well, and I can't afford another M-mount body, even one not made by Leitz. And - you guessed it - I'd like to be able to use the Rokkor on both the M body and the LTM one.

 

Using an LTM lens on an M body is not a problem, since the dedicated LTM-to-M adapters are widely available. As far as I can see, no 40mm lenses that are f/2 or faster exist in LTM. Even the 40/1.4 Nokton by Cosina/Voigtländer, apparently, has only been released in M mount.

 

Suggestions?

[Bill Blackwell Images]

"Suggestions?"

 

Buy your M body (as you plan to) with your one user lens and do what most other folks do -- build your system one lens at a time until the point you need a second "back-up" body.

 

Spending hundreds on dollars on your M-mount lenses to downgrade them to LTM because you can't afford a second M body makes no sense to me.

[Jochen_S]

A beater M should be cheaper than a LTM conversion of the lens. I own 3 LTM Russians and 35, 50, 85mm LTM lenses, but am even reluctant to waste the 40 Euro for a LTM to M adapter to become able to use the Jupiters on my M4P (I have no 35mm M lens yet). - It would be more expensive than each of my lenses!

 

By the way: Which LTM body offers 35mm framelines? - If you're saying CV, buy their M version.

[john_shriver]

Some M lenses have rear elements too large to fit through the throat of an LTM mount. Other than that, it's basically a matter of removing metal and turning threads -- but precisely. You have to remove exactly 1mm from the mounting plane, and you have to get the start of the threads right. The "function" of the RF cam in relation to distance is unchanged.

 

Oh, the M lenses with steep RF cams (some wide angles) might not convert well. Threading them in, the cam might hang up on the roller at the points where it makes sudden jumps.

 

This is also a fine way to reduce the resale value of your Leica glass. Doesn't matter if it's rare, if Leica isn't the one who made it rare.

[jerry_lehrer]

Ron-- In a recent issue of the LHSA magazine "Rangefinder" Tom Abrahamson shows a lens that was converted that way. I think of the

play "Loves Labor Lost" or an Exercise in Futility.

[wdavidprice]

If it can be done it will be done...go boy!

[peter_evans4]

If you haven't already bought the 40mm lens, you might instead investigate the LTM Pentax 43/1.9. It's highly regarded and is supposed to be rare and expensive. Here in Japan at least, it's easy to find and (by Leica standards) cheap. One possible drawback is that it's rather large.

[leica ron]

Thanks Jerry, I'll go look it up on my LHSA DVD :-)

 

As an engineer, I know that in the hands of the right craftsman almost anything can be achieved. But, I always ask the question, is this the right approach ? Is there a better solution to this problem ?

 

From Ronnie's reasoning, which is use an M as a primary camera and a LTM as a back up ... I can think of better solutions ...

 

Oh well, you pays your money and you make your choice ...

[mark_sampson]

A well-maintained or recently-overhauled Leica M camera body won't need a backup until you have saved enough money to buy another one. Going backwards like that with a lens makes no sense to me.

[rondal]

Thanks for all your valuable comments. I have decided to forfeit the idea of converting this lens, and will be buying a low-cost fixed-lens camera as a backup instead of a second interchangable-lens body.

[kaiblanke]

Look out for a Leica CL with a non-working meter - you will even get the 40'2 framelines and all-in-all it will cost you less than USD 300 if you look out for one a bit. If that solution is still too much, forget about a Leica backup at all - I never had a Leica fail on me until now. Rather get another camera like a stylus epic or a T4 or a Rollei 35 and be happy.