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PA-Curtagon vs. R9


swamiji

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Well, I did the search, I checked my PA-Curtagon 1:4/35 for cams, and found none. I looked in Leica Compendium. The Forums Wiki, has one entry and talks about a cam that was added later, but mine does not appear to have that cam. Its an older unit Ser #245XXXX

 

So the basic question is... Will the PA-Curtagon 1:4/35 for Leicaflex work on a R9? Or will it destroy the contacts?

 

This is one case, where the M240 caused me to look at R, as I still shoot film as well.

Edited by swamiji
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For the R8 and R9 you need three cams. I think the ROM contacts don't matter, though I could be wrong. Due to the 7 degrees axis shift the lens does not stop down automatically, but since photographers use it on cmaeras atop tipods taking their time getting everything lined up, that should be of no practical concern.

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I have both the PA-Curtagon and the 28mm PC-Super-Angulon. Although I am not home now, and do not have the lenses to look at directly, I do remember that they have a "fake CAM", whatever that means and whatever function it serves.

 

Just meter at working aperture, and with the lens centered. The meter does not take well to off-center rays. After metering, shift as wanted and shoot. That advice is for film; I have not used the lenses on my DMR. I do not think that the "fake cam" makes much of a difference. Just shoot some pictures and see!

 

And the PA-Curtagon is "safe" on the R9, no risk of damage. Just mount it on and shoot!

 

I'll look at my lenses when I return home and post pictures of the "fake cams".

 

Until then ...

 

Guy

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For the R8 and R9 you need three cams. I think the ROM contacts don't matter, though I could be wrong. Due to the 7 degrees axis shift the lens does not stop down automatically, but since photographers use it on cmaeras atop tipods taking their time getting everything lined up, that should be of no practical concern.

 

Stuart, I hope you don't mind my correcting you here, but R cameras, that is, R3-R9 inclusive, only need the third R cam, and not "three cams". (Indeed, before the advent of the ROM chip, several of the later R lenses were manufactured as "R cam only".) For the R8 abd R9 the ROM chip information adds icing to the cake in terms of focal length information for zooming flash guns, aperture closure dynamics and so on. ROM lenses have the third R cam and the ROM chip.

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They are called null cams and used to provide info to the meter.

 

It hangs down like a stick and does not neatly fit around the edge.

 

Meter stopped down with the lens centered, recompose and shift. Do no change exposure first obtained from lens centered.

 

For fun, Ser whatever is specified is 60mm . If you want to use a pola ser 8 in the shade, only a Leica ser 8 rim is sized so the wheel in the shade will rotate it. You can not just stick any old ser 8 in and expect it to work. Or just use 60 mm and shade with hand.

 

Works well on Nikon with conversion mount.

 

Pretty nice lens with good color.

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If I understand things correctly, the purpose of the R-cam is to tell the camera the maximum lens aperture, and the difference between the maximum aperture of the lens and the actual aperture being used. The camera normally meters at full aperture, for maximum sensitivity, so that this information enables the camera to make the necessary adjustment for the actual aperture being used. With a lens with no aperture coupling, you have to meter stopped down" and the purpose of the null cam (or "static cam" depending on which book you read) is then to give the camera an accurate indication to make a necessary adjustment of zero.

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Well this is all good and useful, but my PA-Curtagon has no cams...

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Edited by swamiji
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Well that is very interesting. But to answer your original question, I would not have thought that the absence of cams would have harmed the camera. (Whether it would then meter properly is another matter. In the Forum discussion pointed to by the Wiki entry, lct shows pictures of a PA Curtagon which clearly has the static cams. The little thing sticking up out of the lens is the R static cam. Your sample appears not to have this, so maybe is an earlier one pre-dating the R range.) So far as the use on an M240 is concerned, there shouldn't be a problem, since the adapter conveys no information, other than, for the Leica branded adapter, that an R lens is in use, and stop down metering is intrinsic anyway.

Edited by masjah
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The camera in question is the R9, not the M240. I am using on the M240 with either the Novoflex or Leica adapter, without issue. Hence the thread title. I wouldn't be concerned except the lens element does move a fair piece within the housing, and the R9 contacts are in the path while using it in portrait.

Edited by swamiji
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Apologies for misunderstanding.

 

I would have thought it would have been OK from the viewpoint of the moving lens element. The later version shown in lct's illustrations has the R static cam, which means that it should be OK for R all cameras, and I wouldn't have thought that the lens had undergone a complete re-design when the R static cam was added. Perhaps you could mount it on the R9 with the lens unshifted, and then very gently shift it towards the camera's rom contacts. if there was going to be interference you should be able to feel it, and back off before any damage was done. On the other hand, the instruction maual does counsel generally against using one or two cam lenses on the R9 and other R cameras. I've never understood how this could cause damage to the camera though.

Edited by masjah
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There is the dilemma, the camera is in route to me as we speak, but the Manuel warns against using 1 & 2 cam lens... It doesn't talk about 0 cam lenses...

 

So I decided to get the counsel of my esteemed forum members, before destroying my new R9...

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There is the dilemma, the camera is in route to me as we speak, but the Manuel warns against using 1 & 2 cam lens... It doesn't talk about 0 cam lenses...

 

So I decided to get the counsel of my esteemed forum members, before destroying my new R9...

Actually, looking closely at the third of your pictures, the black circumferential ring just inside the bayonet appears to have a step in it. Now in Bower's book "Leica Reflex Photography" it is said (page 144 New Edition) that "Static cams 1 and 2 may appear to be a continuous surface on some items". So, I wonder if it is possible that this stepped ring is in fact the combined static cams 1 and 2 alluded to by Bower, so that you have a 2 cam lens? Just a possibility?

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Possibly, but there is no thickness to them, just slight impressions. When I had my SL2, the cams had some substance. Maybe ghosts of cams past?

 

So far, this does seem the best explanation.

 

It's times like this, I wish I brought my library to China with me...

Edited by swamiji
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The reason that 1 and 2-cam lenses should not be mounted on a ROM R body is that one of these cams, cam 1 if I remember correctly, is exactly where the ROM contacts are and would damage the ROM contacts on the R8/R9 body. So, don't try to mount a 1 or 2-cam lens on your R9; Not only would it not meter properly, but it would damage your R9.

 

Your PA-Curtagon without cams is perfectly safe to mount on your R9. I know, it can be difficult to take my word for it as we have not met off this forum, but there is nothing I can do about it ;)

 

I just got back home and I am still terribly jet lagged. I'll post pictures of both the PA-Curtagon and the PC-Super-Angulon soon!

 

Guy

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Guy, what puzzles me is that pre-ROM R lenses equipped with cams 1,2 and 3 (as well as 3rd cam only R lenses) are specified to be perfectly safe with the R8 and R9, but the R9 manual cautions against using 1 and 2 cam lenses without the 3rd R cam. So how can cams 1 and 2 damage the ROM contacts on 1 and 2 cam lenses, but not on 3 cam lenses?

Edited by masjah
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John,

 

You are right!

 

I misquoted information I thought I had!!! I do have 3-cams lenses, as well as 3rd-cam only and ROM lenses, and do use them on my R9 without destroying it (the R9).

 

Although I do not have any 1-cam or 2-cam lenses, their cams have to be in the same positions as the 1st and 2nd cams on 3-cam lenses and, therefore, they cannot damage the R8 or R9 ROM contacts!

 

The R9 manual states:

 

"LEICAFLEX SL/SL2 lenses without

R control cam

 

Leicaflex model lenses and accessories (without the

R control cam) may not be used on the LEICA R9, as

they can damage the camera. If they are to be

used on the LEICA R9 or other Leica R cameras

(from the LEICA R3), they must be fitted with the

R control cam.

 

It is generally possible to modify these lenses;

the Leica Camera AG Customer Service department

will be happy to advise you (see p. 203 for

address).

 

As long as the LEICAFLEX SL/SL2 control cams

are retained, the modified lenses and accessories

can still be used on all Leicaflex models.

Contact strips for data transmission to the LEICA R9

cannot then be added."

 

I can only conjecture that actuating the shutter release of the R9 with a 1-cam or 2-cam lens mounted might damage the inner works of the camera, because of the LACK of the 3rd cam, or else, would it just result in a wrong exposure? But that the simple act of mounting the 1-cam or 2-cam lens on the R9, and NOT triggering the shutter release, should be safe.

If the lack of a 3rd-cam can damage the R9, then can the lack of the "null-cam" also damage an R9???

 

One more Leica mystery!

 

Guy

Edited by gvaliquette
clarification!
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Guy, it is indeed a mystery, and your explanation had also crossed my mind.

 

The only other possibility that I can imagine is that, when the Minolta based R3 body was introduced, perhaps it was necessary, as well as adding the third cam, to "slim down" cams one and two to avoid interference with the Minolta mechanism, and that this "slimming down", as well as still managiing to maintain Leicaflex and SL compatibility, also fortuitously avoided hitting the future ROM chip. But that is total speculation, borne out of a desperation to find an explanation, and may be utter nonsense!

 

What would be nice would be an opportunity to compare cams one and two on a one or two cam lens, with cams one and two on a three cam lens

 

Ho hum!.

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Swamiji,

 

Here are the pictures of the "null-cam", first on the PC-Curtagon, then on the PA-Super-Angulon. The "null-cam"s are both approximately at the 12:00 position and are nothing more that a simple rectangular projection just inside the lens mount.

 

Guy

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