PDA

View Full Version : Diaphram ( iris ) for Protar 14cm lense lost by machinists Jim Gavlin



John Wagoner
12-Mar-2013, 16:19
Years ago, apparently a few years before Jim Gavlin died, I had him mount A Carl Zeiss Jena Protar 14 cm lens in a copal shutter, In the hope that someday I might be able to do some photography with the lens. At the time I did not closely inspect his work. Now, years after his death, I have discovered he did not incorporate an iris into the lens mount. He did not return any spare parts either.

My question is, is there any one who could mount an iris in this lens? Is there a viable work around such as an iris mounted in back or in front of the lens ? Or will I have to search for a similar lens with lousy optics for parts ? The serial number is 78416. Or should I just give up and not spend any more money on this project ?

coisasdavida
12-Mar-2013, 16:28
Protar Series V, f/18? Was it front mounted or split?

John Wagoner
12-Mar-2013, 17:31
Hi: Thank you for your interests. The lens elements screw in the the front and back of the shutter. The Lens does not say what series it is. It looks a lot like an f18 now for sale on ebay. I may have the old lens barrel deeply buried in the stuff I have accumulated in the last 20 years. A good excuse to get organized. John

Dan Fromm
12-Mar-2013, 17:45
John, if the shutter the lens is in has no diaphragm, get another shutter of the same size (and if cock-and-shoot, cock-and-shoot, if press, press), screw the cells into it, and have the diaphragm scaled for the lens. Not very expensive at skgrimes.

I can't imagine that Jim would put cells in a shutter with no diaphragm unless you supplied the shutter. Might you mean that the shutter has a diaphragm and is not scaled for the lens?

John Wagoner
12-Mar-2013, 22:19
Well, I did supply the shutter. I might be remembering wrong about not having the lens barrel returned. Now that I think about it, I do seem to remember a barrel with an iris in it. He did attach a scale on the front the the shutter with F stops associated with a lever, but nothing happens inside the lens when an f stop is selected. Is it possible get an iris type of light reduction and increase in depth of field by having some type of iris immediately behind the lens ? We may have mis communicated. Its a little to late for a clarification from Jim. I will start looking for the lens barrel.

Kirk Fry
12-Mar-2013, 22:36
He may have left the iris out because there was not enough space for both the shutter and the iris between the front and back elements????
Protar V's when they came in shutters were in a special shutter (I can't remember the name, the frilly French jobs) that were really thin so that the elements could be close together. I think I read that copal shutters don't work. Try to find your old barrel and work from there.

Tracy Storer
13-Mar-2013, 07:30
John, does your shutter have one cable release socket or two? Some press shutters have a second socket which, when used, opens the aperture all the way for focusing......if yours DOES have two, try the other one, then try adjusting the aperture.

coisasdavida
13-Mar-2013, 10:21
A picture would help a bunch.

IanG
13-Mar-2013, 10:55
What size shutter is it in ? I have a Ross 141mm f16 these were Zeiss Protars made under licence, mine is a AM (Air Ministry) model and doesn't have the Zeiss patent no, it covers 10x8 with room for slight movements.

Ian

John Wagoner
13-Mar-2013, 17:18
Thank you Tracy you have helped solve the mystery.

I posted this thinking that it was possible for Jim Galvin to had had a senior moment, and it not occur to me that l could be That ignorant. It was Me who had the senior moment !! When the lens is opened for viewing the iris is not visible, even when reduced to F45. If the back cell is unscrewed under these conditions no iris mechanism is obvious. However, if the viewing lever is closed, the shutter stopped down, and then the shutter released, then an iris is visible as it should be. My mistake, and apologies to the memory of Jim Galvin. I enjoyed meeting the man,. At the time he did not express much confidence in his future health, saying I better get anymore machining done soon, so I suppose that put me in the mind set to think he could have made some kind of error. How presumptuous of me. Once again my apologies to the memory of Jm Galvin. I am much relieved to know the shutter works. Looking forward to someday taking a picture again. John Wagoner

Jim Graves
13-Mar-2013, 22:49
John ... where are you located ... we should be able to get you out there for some picture taking.

Jim in Sacramento

coisasdavida
14-Mar-2013, 02:06
What size shutter is it in ? I have a Ross 141mm f16 these were Zeiss Protars made under licence, mine is a AM (Air Ministry) model and doesn't have the Zeiss patent no, it covers 10x8 with room for slight movements.

Ian

A have two of these 14cm f/18 Zeiss in barrel. It barely iluminates 12x16". On 11x14" you can have a sharp image corner to corner.

IanG
14-Mar-2013, 03:06
A have two of these 14cm f/18 Zeiss in barrel. It barely iluminates 12x16". On 11x14" you can have a sharp image corner to corner.

Well I know mine covers 10x8 with room for movements but they are designed for whole plate at f36.

Ian

Tracy Storer
14-Mar-2013, 12:18
John, glad I was able to help, now get out there and make some negatives !