Help with stuck iris in Prontor Professional 1

[StuartR]

Hello all,

I just received a lovely 150mm APO Sironar W in the mail, mounted in a prontor professional 1 shutter. The lens and shutter appear in good shape, though a bit used (they look like they were sitting in a corner somewhere for a few years/decades, but otherwise just fine). The speeds seem accurate and when I got the shutter, the aperture was moving somewhat freely. However, when I tried the secondary cable release port for opening the shutter and iris for focusing, the iris first would close very slowly, and then not at all. Currently it is stuck wide open, and I cannot find a way to bring it back into position. It does not respond to the movement of the ring, nor the shutter. I can see a small lever with a post on the inside of the lens that moves in relation to the secondary cable release, but it moves freely...it does not pull the aperture back into place as it appears it should.

I called SK Grimes, and they were not able to help, and the service bureau they recommend (Flutot's) seems to be closed. Does anyone have any advice? Or perhaps a service manual? I do not think the issue is severe...probably just a bit of oil or gunk in the system or a disengaged connection in the iris mechanism.

[Dan Dozer]

Hello all,

I just received a lovely 150mm APO Sironar W in the mail, mounted in a prontor professional 1 shutter. The lens and shutter appear in good shape, though a bit used (they look like they were sitting in a corner somewhere for a few years/decades, but otherwise just fine). The speeds seem accurate and when I got the shutter, the aperture was moving somewhat freely. However, when I tried the secondary cable release port for opening the shutter and iris for focusing, the iris first would close very slowly, and then not at all. Currently it is stuck wide open, and I cannot find a way to bring it back into position. It does not respond to the movement of the ring, nor the shutter. I can see a small lever with a post on the inside of the lens that moves in relation to the secondary cable release, but it moves freely...it does not pull the aperture back into place as it appears it should.

I called SK Grimes, and they were not able to help, and the service bureau they recommend (Flutot's) seems to be closed. Does anyone have any advice? Or perhaps a service manual? I do not think the issue is severe...probably just a bit of oil or gunk in the system or a disengaged connection in the iris mechanism.


In Ed Romney's 2001 soft bound book called Revised Basic Training in Camera Repair, he says a little about the Prontor and Pronto shutters and that they are very similar to the Compur Shutters when it comes to repair. He doesn't go into detail about repairing the Protor's, but there is detailed info on the Compur Shutters. There is also a diagram of the Pronto shutter. Not sure if this is what you are looking for - hope it helps.

Dan

[David Lindquist]

I suggest Bob Watkins/ Precision Camera Works: https://www.precisioncameraworks.com

I haven't sent anything there myself, at least not yet. He does mention the Prontor among the shutters on which he works. And he is an Authorized Service Center for Linhof and Arca Swiss

David

[Bob Salomon]

In Ed Romney's 2001 soft bound book called Revised Basic Training in Camera Repair, he says a little about the Prontor and Pronto shutters and that they are very similar to the Compur Shutters when it comes to repair. He doesn't go into detail about repairing the Protor's, but there is detailed info on the Compur Shutters. There is also a diagram of the Pronto shutter. Not sure if this is what you are looking for - hope it helps.

Dan

It isn’t.

[StuartR]

Thank you for the suggestions. I am talking to Precision Camera Works. Truth be told, however, sending it to another continent is something I was hoping to avoid. Is this something that a competent repair technician might be able to address, or is it something that requires very specific tools and knowledge? I understand that it would be better done by an experienced technician, but if I have to send it out, the minimum cost will likely be at least 300-500 dollars given the shipping costs and tax climate here (expressed, tracked shipping starts around 50-80 dollars, plus 35 dollars for an customs inspection and export form to avoid tax on the item itself upon return, and then I have to pay 24% VAT on the cost the repair and return shipping. Basically, shipping anything out from here is expensive and a huge hassle. All of which adds up). At that point, it is likely cheaper to just salvage a Copal 1 shutter from somewhere.

[Bob Salomon]

Thank you for the suggestions. I am talking to Precision Camera Works. Truth be told, however, sending it to another continent is something I was hoping to avoid. Is this something that a competent repair technician might be able to address, or is it something that requires very specific tools and knowledge? I understand that it would be better done by an experienced technician, but if I have to send it out, the minimum cost will likely be at least 300-500 dollars given the shipping costs and tax climate here (expressed, tracked shipping starts around 50-80 dollars, plus 35 dollars for an customs inspection and export form to avoid tax on the item itself upon return, and then I have to pay 24% VAT on the cost the repair and return shipping. Basically, shipping anything out from here is expensive and a huge hassle. All of which adds up). At that point, it is likely cheaper to just salvage a Copal 1 shutter from somewhere.

Any experienced camera repair shop should be able to fix it.

Or, since you are in a European country couldn’t you take a trip to the mainland with your camera and just have it fixed on the trip? You could arrange an appointment before hand to make sure parts are available, if necessary.

[StuartR]

Thanks Bob. I will see what I can do. Europe is closer of course, but it is still a three hour flight and we are not in the EU so the same shipping/tax issues apply. I have a trip coming up to the US, I will see if I can get it done in time while I am there if I can't find someone here to do it. I have two people in mind who might give it a shot, but no one that I am aware of is actively servicing large format stuff...just too small of a market here, unfortunately.

[Oren Grad]

I have two people in mind who might give it a shot, but no one that I am aware of is actively servicing large format stuff...just too small of a market here, unfortunately.

One would think that the key capability in this case is the ability to service mechanically-governed leaf shutters. Just thinking of leaf-shutter non-LF equipment that historically has been widely used by professionals, is there anyone local who can still handle Rollei TLRs, or the Hasselblad V-series Zeiss lenses?

[Bob Salomon]

Thanks Bob. I will see what I can do. Europe is closer of course, but it is still a three hour flight and we are not in the EU so the same shipping/tax issues apply. I have a trip coming up to the US, I will see if I can get it done in time while I am there if I can't find someone here to do it. I have two people in mind who might give it a shot, but no one that I am aware of is actively servicing large format stuff...just too small of a market here, unfortunately.

Where will you go in the US?

[Sanford]

Here is a link to a couple of Prontor repair manuals that might be helpful https://www.dropbox.com/sh/703h4whlazrl9in/AAAktoXo3zylV50oPOCVXwaMa?dl=0

[cp_photo]

I have this exact same problem with a G Claron 150mm in Prontor shutter - iris stuck open - I sent it to one repair person who sent it back to me untouched saying they didn't have the parts or knowledge. I ended up searching for and finding a nice copy of the same lens in a Copal 0 shutter and still have the one in the Prontor, but I am not certain how to proceed.

[Bob Salomon]

I have this exact same problem with a G Claron 150mm in Prontor shutter - iris stuck open - I sent it to one repair person who sent it back to me untouched saying they didn't have the parts or knowledge. I ended up searching for and finding a nice copy of the same lens in a Copal 0 shutter and still have the one in the Prontor, but I am not certain how to proceed.

Did you try Bob Watkins?

[StuartR]

Thank you all. I talked to one of the local repairmen, and he is going to take a look at it. He said he was familiar with Prontor Professional shutters. I should know more this week. If he does not work, I will send it to Precision Camera Works, who might hopefully be able to finish it before I leave the US. Fingers crossed.

[StuartR]

Just as a resolution, the local repairman CLA'ed the shutter, and all appears to be working properly again. He said it was just in need of cleaning and lubrication. I am sorry for all the questions. Living in such a small place, I am so used to not being able to get specific services that I just took it for granted that no one here would be willing or able to fix it. I am glad that did not turn out to be the case. Now on to testing the lens!

[David Lindquist]

Thank you for the good news, very glad to hear this.

David