View Full Version : Prontor SVS from Polaroid Pathfinders, are they standard?

4-Jul-2010, 19:43
I see quite often on sale on Ebay the Prontor SVS shutters used on a few Polaroid cameras. Sometimes there is the shutter only, sometimes it comes with a Rodenstock Ysarex, or Tominon/Yashinon lenses.
I have a few lens cells that would fit on standard No. 0 shutters, and i am guessing if those Polaroid Prontors could work.
I have asked around and searched the forum for infos about Polaroid Press No. 1 shutters (Copal and Prontors), but direct experience made me learn much more about them! I purchased four of them, all came quite cheap, but only two proved to be useful so far.
Tha's what i have learnt:
- most of the shutters used for 75mm close-up lenses are not worth buying, they have a very small iris hole (enough for f4.5 for a 75mm lens), because the diaphragm is very a simple one, composed by very few blades. The aperture is round only when fully opened (by means of a "reducer", that decreases the available aperture of a No. 1 shutter by a great margin, and that allows for a coarser diaphragm construction), the "hole" gets fairly round again when stopped down to an almost complete closure.
- not all the shutters are made the same way, there are some, used for the same focal length, that have a decent diaphragm construction, allowing for the used of longer focals, keeping the maximum aperture of the lens.
- to be fully sincere, not one of the four i have is like another one. Everyone is made in a different way! Even shutters with the SAME optic cells and of the same brand, and looking the same from a distance, are somewhat different. After purchasing two shutters that were almost worthless, i started to ask for the exact measures, expecially the diameter of the max aperture. If no answers are given, best to get shutters that are fitted with (or were used for) longer focal lengths, as 105mm or 127mm. The shutters fitted with a Tominon 180mm are rare, and command a higher price, cause the 180mm is less diffused and more sought after.
- i have found a reference to the non-standard spacing of Polaroid shutters, and a hint that the cells have a spacing 2mm bigger than standard. Given the great variance between different models, albeit very similar, i expected to find also different spacing values. So it was, the shutter that is already fitted with lens cells (G-Claron 240mm) has a spacing that is only 0.46mm greater than the standard. That is what i found comparing the lens length on the original Schneider barrel, rim to rim, to the length of the lens mounted in shutter. I took the measures with a good, zeroed caliper, with digital reading.

The other usable shutter was quite dirty, and unfortunately one diaphragm blade came out after operating a lot the shutter, during the cleaning operation made with lighter fluid. The shutter now works perfectly, but one iris blade is misplaced, so it needs to be fixed. I gave the shutter to a friend, who's very good at this kind of jobs, but i still haven't got the shutter back, cause i gave him plenty of stuff. So far only a Linhof Compur No. 00 has been done. It came with a Super Angulon 65mm sold for very cheap on Ebay because of the stuck shutter: it was a pro vendor, maybe he got too lazy, or has got too much stuff on sale, because with a fixed shutter the price would have doubled! :)
When i get the shutter back i will take all the measures, and if somebody is interested, i am more than willing to share my findings.
All in all, for the money i spent on all four shutters, i would have got just one stardard shutter. Maybe not...
From the feeling i got from cleaning and operating all the four shutters, my preference goes towards the Copals. The Prontors need a lot more force and don't work as smoothly, at least for my (limited) experience. They tend to be dirtier also, because they come from old MP-3 cameras, while the Copals are stripped mostly from scientific cameras, that are no so old, and often used in cleaner environments.

If somebody has got he same kind of infos about No. 0 Prontor SVS shutters, i'd be very happy to learn something without having to shell out some money for wrong purchases...:rolleyes:

have fun


- i have read that
done something similar

Rick A
6-Jul-2010, 04:04
I have a Ysarex 127 in Pronor SVS shutter that is excellent. Its just as smooth and clear as my Caltar S 135. I get good use of movements in my 4x5 with it. It surprised me, due to the condition of the Polaroid I stripped it from, you would have thought it was destined for the scrap bin. The camera was toast, loads of dirt, rust and bellows crumbling(and I always thought them indestructable), but the lens and shutter were in pristeen condition(aside from dirty glass)shutter functions perfectly, and all speeds accurate. I have a couple of folders with Prontor SVS shutters and they function perfectly as well.

6-Jul-2010, 10:17
Thanks for your answer.
I have found other positive comments about the quality of the 127mm Ysarex.
I am also happy to understand that, notwithstanding its shorter-than-normal focal length, the coverage is good.
But i'd prefer to separate the lens from the shutter, and use the latter with other lens cells. The Polaroid lens is in a "bundle" with two other large format optics, so it comes as a "plus". I have already THREE lenses in the "normal" range (for 4x5"), and one more is coming... So i have to sell a couple of them, bot getting another one! One of those lenses is a convertible Symmar 135mm, eagerly waiting for a standard No. 0 shutter, to be able to show off its qualities.:)
I even got one Componon-S 135mm, in standard No. 0 barrel, a very convenient size, that offers the chance to reverse the front and back cells when you go past 1:1 reproduction ratio.
That's why i'd be more than happy to learn that the Prontor SVS was made in standard size, but i have more than a few doubts about it!
I'd be more than enough to have at least standard threads, a slight difference in spacing could be easily overcame with a small shim, or (not so easily) dismantling the shutter and doing a little bit of lathe work.

I'm sure that out there must be somebody who did that kind of tests.
And that i'm not the only one who's interested.
If happen to read this message, please share your knowledge.

have fun


17-Jul-2010, 19:03
I have purchased three Prontors SVS sold as broken, i hope that a friend of mine, who's very good at repairing shutters, would bring back to life at least one of them.
If one comes back alive, i will take a few measures and compare it with a standard No. 0 Compur.
If somebody have some interest, just ask, and i'll report my findings.

A nice addition to this very nice forum would be a comparative table of shutters, with quotes.
The infos about standard shutters (from No. 00 to No. 3) are quite easy to find, but some press shutters have a different diaphragm position.
I could also find the measures of Compur No. 2 shutters (three version), and of some of the most recent US shutters. But many are missing, and there is no chart available with at least the most diffused ones.
Probably it's just my fault. If that is true, please post a link/s to the most important informations.
Unfortunately many informations are not easily available. It's a pity, because many people would find very useful to learn if a No. 0 Seikosha shutter used on an old Mamiya Press could be used as a cheap replacement for a No. 0 Compur or Copal.
I have learn some informations the hard way, for example i have never read that pre-war Compurs, as those used on Ikontas and similar cameras, have a standard thread only at the front, the rear is smaller than standard!

Another small example:
Browsing through lots of posts i have learnt that the Meyer Aristostigmat 16cm. (wide angle for 8x10) i just bought, can be fitted on a Compur No. 2, the "thinner" one of the three versions that were made.
I would be a lot happier if only i knew if other shutters shared the same dimensions/spacement. Is there any difference between "Compur No. 2" and "Prontor II"? Were "Prontor II" shutters made with different tube lenghts as well?

Probably somebody out there has all the relevant data, but a single easy-to-read chart is still missing, AFAIK. A real pity!
Of course i'd be very happy to learn that i'm plain wrong:)

have fun


Dan Fromm
18-Jul-2010, 01:53
CJ, here's a project for you. Start with Benoit's list, published here http://www.suaudeau.eu/memo/pratique/Les_obturateurs_centraux.html, and collect the information needed to fill in the gaps in his list.

In other words, instead of begging other people to do work whose results you want, do the work yourself.

18-Jul-2010, 19:51
Thanks for the link. Probably i didn't find it because usually i don't search for french pages. I will review the data and see if i have something new to add to the list, from the documentation i have saved.

BTW, i was not "begging" for anything, and i had already in mind to volunteer for bringing all the available infos together. Now that i have got your "kind advice", i find my goodwill somewhat deflated... Thank you very much for your encouragement!
I have come across very few acid and unwelcoming posts on this forum, but the majority had your signature.
In spite of my not-so-gren age (going for 53), i still find age-induced rudeness quite disturbing. Everybody has his own taste, and probably you can't stomach some other thing. I hope that you would agree at least on this: the forum is definitely the wrong place to show off one's bad nerves!
Enjoy your life and be cool, after all, it's everything about fun!