Jupiter 12 question

[rpj]

There seem to be conflicting opinions on the use of an LTM Jupiter 12 on some LTM cameras, such as the Bessa and the Canon P. Sometimes they work, sometimes they don't seems to be the conventional wisdom.

But what happens if you put an LTM to M adapter on a Jupiter 12? Will it "work" on a Leica M, RD-1, or Hexar RF body?

What about a Jupiter 3 for those of us that cannot swing a Zeiss 50/1.5 sonnar lens?

 

[payasam]

A J-12 worked happily on my M2, and the only 50mm lens I have for the camera is a J-3. The bulbous rear of the J-12 will interfere with the metering on those M bodies that have it.

 

[brachal]

The J-3 should work on any LTM body. If it's in good working order, which can take some luck or work, it's a very, very nice lens.

AFAIK, the J-12 should not be put on a Bessa body; the rear element can hit the shutter. I don't know how it reacts on the Cannon P. They do seem to fit on Leica M and LTM bodies, although the rear element blocks the meter on bodies that have one -- as Payasam noted.

 

[mackigator]

Works on my Hexar RF. Seems to meter ok, at least in daylight (the only conditions I've shot it in). Does not work on my CLE or Bessa R2.

This is a lens to mount carefully on any camera as the rear element will press directly against the shutter on many and on the rest it is a hair's width away.

 

[oscroft]

My J-12 works fine on my M2 and M6 with an adapter - but it does stop the meter working on the M6.

The reason they can hit the shutter on a Bessa is, I believe, because the Bessa has a double-shutter, with the front shutter further forward than the cloth shutter on a Leica (or FED/Zorki).

 

[Mablo]

Newer J-12 models - the black version - can be used with Canon P.

 

[Tim Murphy]

Dear Board,

I'm only resurrecting this thread because it explains a question I had about why the meter on my Bessa L and Bessa R read totally different using a Jupiter J-12 vs a Canon LTM 35mm f2.8. I thought it had something to do with the deeply recessed from element on the J-12 as it always reads 2 or 3 stops low. It never occurred to me that rear element was causing that problem.

I can say that in my use, the rear element does not contact the shutter on either my Bessa's, or if it does, I can find no evidence that it is happening as the rear element is perfect.

Regards,

Tim Murphy

Harrisburg PA 🙂

 

[MarkWalberg]

Dear Board,

I'm only resurrecting this thread because it explains a question I had about why the meter on my Bessa L and Bessa R read totally different using a Jupiter J-12 vs a Canon LTM 35mm f2.8. I thought it had something to do with the deeply recessed from element on the J-12 as it always reads 2 or 3 stops low. It never occurred to me that rear element was causing that problem.

I can say that in my use, the rear element does not contact the shutter on either my Bessa's, or if it does, I can find no evidence that it is happening as the rear element is perfect.

Regards,

Tim Murphy

Harrisburg PA 🙂

Well , explain to us who have no Bessa. What is the issue, Tim.

 

[Tim Murphy]

Well , explain to us who have no Bessa. What is the issue, Tim.

Dear MarkWalberg,

The issue is supposed to be that due to the bulbous rear element on the J-12 it can possibly or potentially contact the shutter mechanism on the Bessa cameras. It is said that the shutter design on the Bessa's makes that a probability. I haven't seen it. It is also said that it can also possibly contact the shutter mechanism on certain Canon rangefinders. I've also used it on a Canon 7 with no issues. After research on the internet, other people have reported no issue on a Canon P, and some have reported no issues at all on Canon cameras.

The rear element does however greatly affect the light meter on my Bessa's. Apparently, the rear element somehow limits the view of the meter sensor. I'm not sure how it does, but I can report that on both my Bessa's it reads 2 to 3 stops low with amazing consistency. With 400 speed film and using sunny F16 rules an exposure on a slightly overcast day that should be f8 @ 1/250 comes up f8 at 1/60 or even 1/30 with my Bessa's. With my Canon 35 f2.8 on my Bessa's I get f8 1/250.

I'm still trying to figure out the RF world and only resurrected this old post because it explained the metering problem, otherwise I would have asked a question about why my meter is off when using the lens on my Bessa's.

Regards,

Tim Murphy

Harrisburg PA 🙂

 

[MarkWalberg]

Dear MarkWalberg,

The issue is supposed to be that due to the bulbous rear element on the J-12 it can possibly or potentially contact the shutter mechanism on the Bessa cameras. It is said that the shutter design on the Bessa's makes that a probability. I haven't seen it. It is also said that it can also possibly contact the shutter mechanism on certain Canon rangefinders. I've also used it on a Canon 7 with no issues. After research on the internet, other people have reported no issue on a Canon P, and some have reported no issues at all on Canon cameras.

The rear element does however greatly affect the light meter on my Bessa's. Apparently, the rear element somehow limits the view of the meter sensor. I'm not sure how it does, but I can report that on both my Bessa's it reads 2 to 3 stops low with amazing consistency. With 400 speed film and using sunny F16 rules an exposure on a slightly overcast day that should be f8 @ 1/250 comes up f8 at 1/60 or even 1/30 with my Bessa's. With my Canon 35 f2.8 on my Bessa's I get f8 1/250.

I'm still trying to figure out the RF world and only resurrected this old post because it explained the metering problem, otherwise I would have asked a question about why my meter is off when using the lens on my Bessa's.

Regards,

Tim Murphy

Harrisburg PA 🙂

Thanks for clarifying that Tim. I’ve made some good pictures without using a viewfinder, and can do without a meter much of the time. I can imagine how the deep back element of the J12 or Biogon could affect some meters. Thanks for clarifying.

 

[rick oleson]

I have no problem with it on a Canon P. I’m sure it would not be happy on a CL or an M5 because of the meter cell in front of the shutter. The Contax Mount version will not fit on postwar Contax IIa and IIIa.