Prontor 1 Polaroid 4.7 press shutter and a nice gift from Prontor :)

[eumenius]

Hello friends,

I want to tell you a story of good marketing. I bought recently on APUG a nice set - a Prontor Press size 1 shutter, beginning from f/4.7, and Tominon 127/4.7 barrel lens. I wanted to have a good lens for close-ups, so thanks to the kind advices of Jim Galli I've got it. When I unscrewed the old delaminated 127/4.7 Ysaron from the shutter, I found a strange thing - the rear cell of Tominon didn't want to screw in, stopping at 1 mm at least before the proper position! When I looked in to see what's wrong, I noticed a round "light baffle" inside the shutter, entering the special groove on Ysaron old cell, and preventing any other glass from being mounted! Wasn't it just a nice gift from Prontor, eh? The guys really didn't want anyone to mess up with their shutters. The shutter was a bit sticky, so I disassembled it for CLA, opened the diafragm, and removed the goddamn baffle (filed out the peens that kept it in place). This baffle was not needed there for anything, and its opening was even larger that the one of the diafragm ring, so it was made apparently to make people's life more difficult. Now my Prontor accepts any Copal 1 sized glass, and works just fine - as well as Tominon, a very good lens. If anyone has such a shutter, don't be afraid to remove this baffle - it's a marketing trick, nothing more.

Cheers, Zhenya

 

[Donald Qualls]

Thanks, Zhenya -- I've got one of those Prontors, also, that came to me without the Ysaron glass, and a Skopar 13.5 cm f/4.5 that fits the threads -- now all I need is time to take it apart (and recalibrate the aperture scale) and I'll be able to use that lens!

You had to open the diaphragm -- is it reasonably possible to do that without having to reassemble the blades?

 

[eumenius]

Donald,

I had to reassemble the blades in both shutter and diaphragm - that's what I do every time when I CLA the shutter, just to make sure that it would run without troubles another thirty years But to remove the baffle, all you need is to disassemble/reassemble the diaphragm blades (though if you do it carefully, you can avoid even this). There are only five blades, to a bit of patience and non-magnetic tweezers would help The Prontor has a "jumping" diaphragm - one socket for cable release opens the diaphragm and shutter fully respectless to the aperture set, and another socket is for taking a picture.

To do the job, remove the aperture setting lever (three screws with the shims under, rear side), take away four small screws with black heads. Carefully lift off the rear part of shutter (strangely, the access to its guts is from rear, not front as usual). Notice that the diaphragm plate (to which the baffle is peened) is spring-loaded, and there's a lever that sets the aperture - you have to reassemble it back this way, putting the spring's end under the pin on the underside of said ring, and the lever's end under another pin. The normal position of diaphragm now is "closed". Make a mark on one side of the plate and shutter's body to re-align it back later. Remove three screws securing the plate, and very carefully lift it (there's a spring, so be careful). If you didn't shake it, the blades would be in place. Remove the peened heads on the baffle with needle file, throw away the baffle and four pins. Reinstall the plate, loading the spring and putting the lever in right place. If the pins on diaphragm blades have shifted somehow and don't enter their hole on the plate easily, you can shift them a bit with some needle - very carefully. Fasten the screws back, check the diaphragm - if you have done it right, it should open fully if you lift the actuating pin on the rearside setting lever, and snap back when you take your finger off the lever. Reinstall the rear assembly and diaphragm ring (putting the pin of the lever on the profiled part of the ring). Enjoy your cured Prontor!

Cheers, Zhenya

Thanks, Zhenya -- I've got one of those Prontors, also, that came to me without the Ysaron glass, and a Skopar 13.5 cm f/4.5 that fits the threads -- now all I need is time to take it apart (and recalibrate the aperture scale) and I'll be able to use that lens!

You had to open the diaphragm -- is it reasonably possible to do that without having to reassemble the blades?

 

[Donald Qualls]

Mine isn't quite identical to yours -- it's a Prontor Press, and has only a single cable release socket, but I can see the four little pins around the baffle, and it looks like it'll be much easier (because no press focus -- it has a T setting instead) to get the aperture setting ring out and take the baffle off it. I've got a nice set of Swiss needle files I bought 20-some years ago, and every few years they earn back what I paid for them, over and over -- looks like they're about ready to do it again.

And only five blades I can handle -- I reassembled the shutter blades in a smaller press shutter a while back, five blades plus a sixth overlapping one (to keep everything moving smoothly, I gather). Not even tweezers, just fingernails and a tiny screwdriver tip to push them around; no sweat. There's a project for the weekend...

 

[eumenius]

Oh, if your shutter is a Press variety, it should be relatively easier to fix - no auto aperture, etc., and if you lift the rear cover of the shutter with a real care, the shutter blades won't spill There are indeed five blades, and one extra under the first one (that's one on the top when looking from the rear side) - a good design, quite a lightproof one. So you would need to reassemble the aperture blades only, and the easiest way to realign them with the holes in an aperture plate is to shift it back and forth a bit, and to use a needle to push them a bit here and there by side. Just take out the plate, and file away the heads of the pins - don't mind damaging the baffle, it's a rubbish anyway Gently pry the baffle away from the plate, the pins would be easy to remove too. Good luck, and let me know how would be the result! Looks like it's a good way to get a functional Copal 1 equivalent for next to nothing

Cheers, Zhenya

Mine isn't quite identical to yours -- it's a Prontor Press, and has only a single cable release socket, but I can see the four little pins around the baffle, and it looks like it'll be much easier (because no press focus -- it has a T setting instead) to get the aperture setting ring out and take the baffle off it. I've got a nice set of Swiss needle files I bought 20-some years ago, and every few years they earn back what I paid for them, over and over -- looks like they're about ready to do it again.

And only five blades I can handle -- I reassembled the shutter blades in a smaller press shutter a while back, five blades plus a sixth overlapping one (to keep everything moving smoothly, I gather). Not even tweezers, just fingernails and a tiny screwdriver tip to push them around; no sweat. There's a project for the weekend...

 

[Donald Qualls]

Since I don't care about the baffle, I might use a Dremel to remove the pins -- MUCH faster than a tiny file... I'll try to remember to post back here after doing the work. Would be nice to have that Skopar in a shutter.

 

[eumenius]

A Dremel would do it in a moment - I just didn't happen to have it on my workplace And the baffle is not a valuable thing, so damaging it a bit won't be a bad idea. Just grind away the pins with your Dremel not too close to your open shutter, just to keep it safe from metallic dust.

Good luck, Zhenya

Since I don't care about the baffle, I might use a Dremel to remove the pins -- MUCH faster than a tiny file... I'll try to remember to post back here after doing the work. Would be nice to have that Skopar in a shutter.

 

[Frank R]

Zhenya, I think you have stumbled on something quite helpful to a lot of LF photographers out there.

I have two of these shutters myself. It is nice to know that I can now use them for something other than close-up work.

I am posting a picture for others to see what we are talking about.

 

[eumenius]

Yeah Frank,

equip yourself with a Dremel tool or a hand file, a screwdriver and some patience, and remove this baffle - voila, you got a shutter that would prefectly accept the Copal 1 glass!! I'm unsure about wide-angles (as with all press shutters, the iris is a bit closer to the rear cell, about 0.75mm) - but all other glass designed for Copal 1 should fit. You have to re-do the aperture scale for each glass, but that's not a real trouble.

Have fun, and good luck - seriously, I wonder why nobody before me didn't apparently get rid of this annoyance.

Cheers, Zhenya

Zhenya, I think you have stumbled on something quite helpful to a lot of LF photographers out there.

I have two of these shutters myself. It is nice to know that I can now use them for something other than close-up work.

I am posting a picture for others to see what we are talking about.

 

[cperez]

On the topic of Prontor shutters:
Does anyone know of a reliable resource for parts? One of my Prontors lost it's angled tab off the aperture arm. I need a replacement.

 

[eumenius]

Ahem, is there such a place? Does Prontor still exist at all? I just don't know it... maybe it's easier to attach some other thing in place of broken tab, or find a "parts" grade shutter?

On the topic of Prontor shutters:
Does anyone know of a reliable resource for parts? One of my Prontors lost it's angled tab off the aperture arm. I need a replacement.

 

[Donald Qualls]

Just grind away the pins with your Dremel not too close to your open shutter, just to keep it safe from metallic dust.

Having recently cleaned up a Bantam RF shutter that was just chock full of aluminum shavings (from where? No idea), I'm very sensitive to the harm metal filings could do inside a shutter. Fortunately, my usual working area for grinding is well away from where I work on my shutters.

More by Monday, I hope...

 

[eumenius]

These aluminium shavings are usually coming from some drilling of assembled lens/camera, no doubt I well remember one Kiev-88...

Good luck, and write back how it's going - Zhenya

Having recently cleaned up a Bantam RF shutter that was just chock full of aluminum shavings (from where? No idea), I'm very sensitive to the harm metal filings could do inside a shutter. Fortunately, my usual working area for grinding is well away from where I work on my shutters.

More by Monday, I hope...

 

[Donald Qualls]

Okay, I got the baffle out of my Prontor Press today. I took a few pictures in the process (they're digital -- sorry, but that's the only kind I can get back this quick, other than Polaroid, and I didn't even think about loading my Pola 350 and installing the close-up kit; probably would have gotten better shots!).

On mine, I had to remove the entire diaphragm assembly from the back plate, and then separate the moving and fixed plates to get the moving plate out and remove the baffle. This necessitated reassembling the (ten) aperture blades, but fortunately after a few minutes of thought it turned out to be a fairly easy process -- I'll be less apprehensive next time I need to perform this operation (which I might do on this shutter at some point, to widen the available aperture -- which will require milling or filing the stop on the "wide" end of the operating slot in the backplate, and boring the hole in the fixed plate larger; pretty simple, as modifying complex devices goes).

I found that it was simplest to remove the baffle by using my drill press with a 3/32 (appr. 2 mm) twist drill to drill out the small ends of the pins; both pins and the moving plate are brass under the blackening, and drilled like butter. Even better, the operation left the moving plate's surface perfectly smooth right up to the edges of the holes, so no snags after reassembly.

Removing the baffle left an area on the moving plate that was natural brass colored, but a pass with a Sharpie (permanent black marker) nicely blackened the exposed brass (to reduce flare and reflections).

After all was completed and the shutter reassembled, the back group of my Skopar mounts perfectly. Unfortunately, the front group won't mount -- I hadn't tried it before, because the back group was interfering with the baffle, but I now see the threads in the shutter and the threads on the front cell are both too short and won't engage before the cell's shoulder meets the shoulder on the shutter's mounting sleeve. Sigh. Now I'll have to see about swapping shutters with my Componon, and have to recalibrate *both* aperture scales...

 

[eumenius]

Donald,
Your shutter seems to be older that mine - and the diaphragm is made in different way... but the baffle is exactly the same in both models The drilling can be a better solution that filing away the head, but I just didn't happen to have a micro drill machine in my lab The area under the baffle in my case wasn't colored differently, too - it was the same black surface.

I can't understand what's wrong with your set - why the front cell doesn't mount? Maybe it was just designed for something else? My Tominon cells fit perfectly... the threading in my Prontor on its front begins from about 2.3 millimeters from its shoulder, making it exactly the very same as Copal 1. Maybe this Scopar glass was made for a very special shutter? Another nice gift, this time from Voigthlaender

 

[eumenius]

Well, some new information - today I've finally managed to get this 150/5.6 Symmar-S in Sinar DB ($125, glass is truly perfect, ligth bluish old MC(?)). I unscrewed it from that DB thingie (the cells are originally Copal 0, yes, with some bushings made to fit Copal 1), and put directly in my healed Prontor Polaroid. The aperture scale is 1/3 stop "slower" than the scale of Tominon 127/4.7 - the Symmar 5.6 is located between 4.7 and 5.6 marks on the shutter. The whole set works perfectly and takes fine pictures, I tried it today

 

[Donald Qualls]

I can't understand what's wrong with your set - why the front cell doesn't mount? Maybe it was just designed for something else? My Tominon cells fit perfectly... the threading in my Prontor on its front begins from about 2.3 millimeters from its shoulder, making it exactly the very same as Copal 1. Maybe this Scopar glass was made for a very special shutter? Another nice gift, this time from Voigthlaender

The Skopar I have wasn't designed for anything exotic; it came off a Voigtlander plate camera, pre-WWII (uncoated) and was mounted in a #1 rim-set Compur (which, when I received it, had been partly disassembled, had springs sticking out and bent over and clipped off, and has been designated as a parts mine).

However -- the front group cell has a relatively short thread, which is fine on the Compur, where the threads reach all the way to the front end of the sleeve. On the Prontor Press, there's a recess inside the sleeve for about 3-4 mm before the threads start -- and the Skopar front cell threads are less than 4 mm long. The lens drops into place, registers perfectly on its shoulder -- but without engaging the threads.

I suppose I could ask around whether anyone wants a Prontor Press converted to accept standard #1 size lenses, and will trade a working #1 Compur for it... Folks with a Speed Graphic and Grafmatic might consider this an improvement.

Nah, it'll be easier to swap shutters. The Componon is in a #1 Synchro Compur, so I should be able to take the aperture scale off the original Compur that came with the Skopar, and then only have to recalibrate one scale (on the Prontor Press) for the two or possibly three focal lengths available with the Componon.

I'll get there...