Copal or Compur-Which is the Best?

[tgtaylor]

Last week I purchased a lens with a Compur 3 shutter. All my other lens are in Copal shutters. Although I searched online, I could find no real comparisons between the two except that some people (at least one) believe that it is harder to work on a Compur than a Copal. Other than that the only difference I have been able to determine is that the Compur 3 weighs more than the Copal 3. The lens, a Schneider 360mm Symmar-S, was offered in 4 different shutters when new but I haven't been able to find any comparisons of the benefits of one shutter over the others. Anyone with any insight on this?

Thomas

[Walter Calahan]

The one that works correctly. I've never noticed a difference.

[Ole Tjugen]

Personally, I like Compound shutters in those sizes.

But there isn't much difference. Except for the Compur Electronic; I think I may have one in a drawer somewhere.

[Greg Lockrey]

My really old Copals work better than my really old Compurs. That's all I can say.

[Emmanuel BIGLER]

Hello from Europe

Copal or Compur-Which is the Best?

The Euro-patriot's answer : Compurs are the best : Natürlich !

Compur shutters, made in Munich, Germany, existed long before Copals arrived on the market.
Before the second wolrd-war, there were many independant European manufacturers of shutters for the camera industry. And there existed shutters made in the USA, that can still be found on graflex lenses (the Ilex, the Acme, ...)

The two most respected shutter brands in Germany were Prontor (the company is named : Gauthier and still exists) and Compurs (the company was origially named Deckel, their core business was fabrication of precision machine-tools, eventually Deckel created a separate factory for shutters named Compur Werke).
As of the fifties, Gauthier and Deckel were controlled by the Zeiss Foundation, and with the collapse of most consumer-grade German cameras after 1970, Zeiss closed the Compur Werke in Munich and transferred everything to the Gauthier factory in the Black Forest (the place is named Calmbach).
Hence there exist several generations of compurs !
The last Compur models described in Schneider's and Rodenstock's brochures of the nineties were made by Gauthier. The premium you had to pay for a Compur vs. a Copal was about $300.
From a user's point of view, this premium was difficult to justify. Copals of the nineties had no click-stop, and that was almost all that could be said except of course the deserved reputation of the compurs. After the demise of Compur production, Schneider added in their factory some click-stops to the Copals in order to emulate what had been one of the standard Compur feature.

But the mounting threads and important dimensions are exactly the same for most modern (post-1950) shutter brands, in fact Prontor and Compur had set the de-facto industry standard for #0, #1 and #3 shutters. Hence Copals comply with this standard and (with some subtle restrictions in the case of top-class wide angle lenses that have to be carefully factory-mounted and adjusted on the shutter) you can formally swap a compur for a copal and vice-versa.

So the story is exceedingly simple, compurs were the best but were costly, and like most of the European camera industry, dissapeared due to the pressure of Japanese competition. And Copals are excellent products, otherwise they could not push Compurs out of the market !!
I do not know when the American Ilexes and Acmes dissapeared, but the story is probably similar ...

Compurs are so good and reliable that they will survive for years if properly maintained. May be, only the Compounds with their pneumatic system could live longer than compurs (ask Ole for a primer about Compounds shutters ;) )

I have many compurs at home on several cameras, including last generation of compurs made in Calmbach on recent view-camera lenses. I also have recent Prontor Professional shutters, built in the same tradition as the Compurs, but they are self-cocking and with some additional features not offered by copals.

Compurs are designed to operate with a minimum of oil lubrication at some critical parts.
Exactly like a mechanical watch. Compurs have to be cleaned, lube'd and adjusted (CLA'ed) from time to time, but there expected lifetime is something like a century if you take care of them properly.
I offered my brother-in-law a Voigtländer Avus fitted with a compur shutter of the 1920's (on a skopar lens). This old shutter works perfectly 90 years after being fabricated.

Copals apparently can operate on longer periods of time than compurs without being CLA'ed, but I have little experience with them, the only Copals I have are less that 10 years old, they are youngsters if compared with my 1936 Bessa rangefinder 2x3" camera equiped with a Compur-rapid ;)

[Bob Salomon]

One of the big differences is that Copal are still made and Compur and all other mechanical shutters from Prontor Werke have been out of production for many years/decades.

[Frank Petronio]

All things being equal, I prefer a Compur to a Copal, with the understanding that like a fine German car, it will require shorter service intervals than its Japanese counterpart. I just like the design and feel of Compurs, and knowing the history helps.

Likewise, I'll get the Linhof- or Sinar-selected German lenses over fine Fujinons and Nikkors. Nothing is wrong with a rebranded Caltar in a Copal, I am sure many finer photographers than me use them far better than I could. It's just my snooty personal preference.

Besides, I never keep anything long enough that it requires service, lol.

[E. von Hoegh]

Compur.

[Ole Tjugen]

Maybe what forced Compur out of business wasn't Copal, but Compur? The main sizes were settles in the 1920's, and on one occasion I found that the shutter on a fairly new (1990's) lens had gummed up and was slow, so I unscrewed the cells and put them in a 1924 dial-set Compur I had just checked and found accurate. Admittedly that was a #1 and not a #3, but it seems to me that someone who makes something that works well for a century is going to sell very few replacements.

[Bob Salomon]

Compur had many features that Copal did/does not have. Click stops have been mentioned, 1/3rd increments on the 1 and 3 and 1/2 stop on the 0. But they also accepted accessory controllers that would let you select the aperture from behind the camera and some would also let you select the shutter speed. That is what the small gear wheel on the back of later Compur shutters wwas for. While these add-on sticks had to be scewed onto the back of the shutter Prontor later added this fature to the Prontor Professional series but those accessories were added to the shutter without tools. The 0 sized Compur did not have this feature though.

[Leigh]

The Compur is a much more rugged product than the Copal.

As a repair tech I've worked on both, and prefer the Compur for long-term reliability.

- Leigh

[edp]

Compound > Compur > Copal > Lens cap > Hat.

And then, trailing far behind, all the misshapen rusty pressed steel junk that it was a miracle it ever worked in the first place.

[tgtaylor]

Thanks for the enlightened discussion everyone and especially to Emmanuel BIGLER for the wonderful history of the Compur!

I have the lens mounted on a 110mm Toyo board (I have the adaptors) so I don't yet know if this shutter has that gear that would allow you to view the f stop that Bob mentioned. The serial number is 14,086,xxx so according to the Schneider web site the lens was manufactured between October 1983 and January 1985.

The lens itself appear to be in mint condition with a very light sprinkling of fine dust on the inside element which I imagine got there as a result of removing the rear element, and not a hint of Schneideritis which kind of surprised me. The caps, as is the glass, are pristine and show none of the typical scuffs one would expect from being handled much and I really like the piece of felt placed in the center of the front cap to prevent accidental scratches or smudging of element. I also like the 1/3 stop aperture click stops. The only thing that I don't like about the lens is that it requires a cable release that has a long throw to trigger the shutter. Luckily 2 of my 3 cables have that.

I bought this lens to use with the Toyo 810G but to date haven't any photos with it yet. Although the rear element is too large to fit the throats of my field cameras, this lens will also work well on my Toyo ROBOS with the standard bellows. With a huge image circle - 491mm - I should be able to get all the movements both cameras provide. It's going to be fun using it!

Thomas

PS: With respect to CLA, how often should this be performed on shutters?

[IanG]

Compur, my oldest is pre-WWI approx 1913 with a 165mm CZJ f6.3 Tessar and still working perfectly as are all my other Compur's around a dozen Rim set and about 9 or 10 Dial set.

Of my Copals 2 need a CLA, and two repair, they may be more modern but they'll wear out faster, they just aren't as robust.

Ian

[Frank Petronio]

The gizmo that Bob mentions - which allows you to set the shutter from behind the camera - is cool for the studio but a bit bulky and fragile for field use. I've removed them when I've gotten lenses with them installed.

I don't think they are less robust than a Copal, but perhaps a Copal has looser tolerances and can withstand some old grease and grit a bit better? Think of it as a tightly-fitted Panzer tank versus a sloppy Russian tank in WW2. The Panzer performed better but the Russian tank started in the cold when the Panzers' seized up.

[rdenney]

I don't think they are less robust than a Copal, but perhaps a Copal has looser tolerances and can withstand some old grease and grit a bit better? Think of it as a tightly-fitted Panzer tank versus a sloppy Russian tank in WW2. The Panzer performed better but the Russian tank started in the cold when the Panzers' seized up.

Yes. I've had Pentacon Sixes opened up and compared them with the internals of a Kiev 60. The former are finely made and engineered, but perhaps too finely engineered for the quality of the manufacture. The Kiev 60's are like Ilex shutters--designed to be functional in the way that a cheap alarm clock is functional. Not as precise, and not as pretty, but once they work they tend to keep working despite abuse.

On subject, I would rather have a newer Copal in good condition than an ancient Compur that was worn out. All my Copals tend to be newer than all my Compurs, and they tend to be in better running condition as a result. Maybe that would reverse if I had them all CLA'd.

Rick "who tries to replace shutters with the same brand so that the aperture scale can stay with the glass" Denney