Copal vs Compur

[Bob Salomon]

Hmm. I thought Wollensak, or Ilex, invented the 'modern' leaf shutter in the early 20th century, and Prontor/Compur licensed the design and perfected it. But if so, it was long before my time... and I have no reference to back that statement up. However, based on much personal experience, I'll say this: if your Compur or Copal is in good shape, ain't no difference 'tween the two. They're both excellent shutters.
And a data point- on my recommendation, my then employers bought a Schneider 150/9 G-Claron in 1988; it came in a Compur shutter. That shutter was still working just fine the last time I used it, six months or so ago.

Sorry Mark but Valentin Linhof introduced the between the lens leaf shutter and by 1899 Kodak was selling a camera using this shutter. So were Zeiss and Dallmeyer. After Linhof's death in 1929 the shutters were sold to the Deckel company in Munich which became part of the Zeiss group of companies and the shutter became part of Prontor Werke and eventually became the Compur shutter.

And there was a big difference between Compur and Copal shutters. Compur shutters (later ones) had click stops for the aperture (1/3rd stops), Copal didn't. And on some of the very late ones the click stops could be disengaged. In addition Compur shutters could be equipped with aperture and shutter speed sticks that let you control the aperture or the shutter from behind the camera. If you have a Compur shutter with exposed gear wheels on the back of the shutter then you have a model that would accept these sticks. Copals never had this ability. But, of course, Copal shutters were a good deal less expensive then Compurs. So most lenses came in Copal afetr the 60's.

[Kerry L. Thalmann]

And a data point- on my recommendation, my then employers bought a Schneider 150/9 G-Claron in 1988; it came in a Compur shutter. That shutter was still working just fine the last time I used it, six months or so ago.

As a backpacker and nut for saving weight, I always favored the late all-black Compur 0 as it's about 30g lighter than a Copal 0. Hey, every ounce counts.

Oddly, the Compur 1 is heavier than a Copal 1. In the size 1, I prefer the Copal Press shutter as it is a size 1 shutter that weighs the same size as a standard Copal 0. So, size 1 shutter at a size 0 weight. That's a savings of about 2 oz. per lens. And, I also liked the set and forget aperture feature of the Copal Press. No more forgetting to stop down to the working aperture after compasing and focusing.

Kerry

[tbeaman]

Aside from everything that's been said already, one thing I know is that most Compurs have more than the silly 5 blades in Copal diaphragms, and most of them have classy, beautiful chrome accents. I have an irrational hatred for all-black photographic gear. I'd really like to know who started that awful trend.

There are three types of photographers. Ones who like wood and brass, ones who like black and chrome, and ones who like all-black plastic amorphous blocks.

(I'm being incendiary, but try not to take it too seriously; I'm just having fun).

[Vaughn]

...There are three types of photographers. Ones who like wood and brass, ones who like black and chrome, and ones who like all-black plastic amorphous blocks...

I do like my wood and brass 5x7 Eastman View and 8x10 Zone VI. The marks that end up on them out in the field are badges of honor.

My all-black PocketView is a cool lightweight photo ninja in 4x5, a monorail ready to follow me anywhere...down to the bottom of the Grand Canyon or up to the top of Mount Ngauruhoe.

But my first camera was the classic black and chrome Rolleiflex TLR. A beauty in its own right. The fit into the hands is perfect. Form follows function follows form. A classy machine.

But then I even like the cardboard box pinhole cameras I have made, not to mention my fun all plastic Diana! Getting close to a Space Age camera -- I am using a wood and carbon fiber 7"x17", incredibly well designed and built be Richard Ritter. Weighs about 60% of my 8x10. I seem to like any camera I can use.

My normal lenses are in the Copal shutters -- all modern plasmats. I do not own anything in a Compur. I have a TR convertible in a Betax, and a 6.25" Wollie in an Alphax. And of course, barrels with no shutters. I have a front-mounted Calumet/packard shutter affair I'd like to adapt to my 8x10. Whatever works!

At work we have a couple lenses in Compur shutters -- they don't work at the present time. Maybe early next school year when we have the money for repairs.

[Kerry L. Thalmann]

Aside from everything that's been said already, one thing I know is that most Compurs have more than the silly 5 blades in Copal diaphragms, and most of them have classy, beautiful chrome accents. I have an irrational hatred for all-black photographic gear. I'd really like to know who started that awful trend.

There are three types of photographers. Ones who like wood and brass, ones who like black and chrome, and ones who like all-black plastic amorphous blocks.

(I'm being incendiary, but try not to take it too seriously; I'm just having fun).

I have a few lenses in the older chrome ring Compur 3 shutters (one of the last 165mm Angulons ever made, it was part of a small production run Schneider did for Sinar in the late 1970s and a 360mm Schneider APO Artar). They still purr as smoothly as the day they were made close to 35 years ago.

The one problem I have with those shiney chrome rings is they can reflect light sources and cause hot spots on the subject if you aren't careful when shooting backlit subjects.

I'll have to check and see how the weight of the late all-black Compur 3 compares to the current Copal 3. I've never bothered to check the weight becuase I figure any lens that comes in a shutter this large isn't exactly an untralight lens to begin with. Although, it's all relative. Relative to the coverage, lenses like the 240mm, 270mm and 305mm Computar, the 450mm Nikkor M and 600mm Fujinon C could be considered ultralight lenses for the ULF formats.

Kerry

[Emmanuel BIGLER]

Any idea when Schneider stopped offering Compur shutters?

As Bob says, Prontor Werke, a company controlled by the Zeiss Foundation, stopped manufacturing compurs and prontor professional mechanical shutters around ~ Y2K.
I bought two new lenses mounted on the prontor professional in 2001 ; one Schneider and one Rodenstock. At the time, the option was still offered between the compur, the prontor, the copal, the copal press, and several electronic shutters : the Rollei and the Horseman ISS (not International Space Station, but out of reach for me, though ).
The premium you had to pay for the compur or the prontor over the copal was in the range of 200 to 300 euros. No surprise then to learn what happened afterwards : those beloved German mechanical shutters were discontinued.
In 2003 or so the stock of compurs/prontors was about to get depleted at Schneider and Rodenstock, I still could get a new apo-grandagon 55 on the prontor pro.

I have one apo-Symmar on a last-generation, Calmbach-made, compur#1, bought used. I would certainly never swap this compur for a copal !!
Once, I a had an exchange with Swiss photographer who wanted to swap his Prontor Professionals against Copals for some unknown reason. The shutters fitted some modern high-performance wide-angle view camera lenses. I told him that if he had his prontor professional shutters available for sale, I would buy them from him immediately, but I warned him against the fact that on a top-class modern wide angle lens, for a complete shutter exchange (and not only swapping lens boards, which is not critical) he should return the whole lens to the factory so that tiny adjustements in the new shutter fitting could be performed with the utmost precision in order to retain the full original performance of the lens. Being Swiss, hence born in a precision country, he followed my advice and asked for a quotation for a new copal and subsequent fine adjustments & calibrations ; eventually, he found the price really dissuasive, and he kept his prontors.... (too bad for me..)

I am not sure that the last generation of compurs for view camera lenses made at prontor Werke in Calmbach (in the Black Forest) is exactly the same mechanism as the beloved synchro-compur shutters fitting millions of "alive-and-well" Rollei-TLR or Hasselblad lenses before ~ 1976, when the Deckel-Compur factory in Munich closed down, the Compur brand & fabrication being transferred to the Prontor Werke (both companies had actually been controlled by the Zeiss Foundation for decades)

[Frank Petronio]

The wide chrome ring and later black ring Compurs and Prontors were all five-blade apertures - these were from the late 1960s on. The last "circular" aperture Compurs (using many blades) have the narrower chrome ring (early 1960s).

Being the discount version, Copals never had circular apertures. American Acmes, Illexes, Wollys and the like were circular.

Note that the aperture blades and shutter blades are separate. I'm not sure whether it was the lens company or the shutter company who built the aperture, but I assume the lens designer specified it.

I prefer the rounder apertures but I also like the later shutters... everything is a compromise. But if you shoot wide open, the aperture blades never close so it is always circular. I end up doing this more often than you might think, at least in backlit situations.

I also like the newer Copal and Compur 3s because they have higher shutter speeds. The older large shutters, like the Acme #5, have a hard time firing at a 1/40th (real time). The compromise is that the older shutters seem smoother firing to me, sometimes the modern #3s feel like a gun going off.

The Prontors, which are self-cocking, are as well made as the Prontors except they are always short of the Prontor's top speed (they are slower - 1/250th on the smaller size Prontor versus 1/500th on the Compur/Copal - I think the Prontor 3 tops out at 1/125th) and the self-cocking mechanism requires extra force to fire the shutter, which I don't care for in spite of the convenience of not having to cock the darn thing (I fear it adds to vibration too).

All things considered, a late model Compur is probably the best. I wouldn't pay a lot extra for one over a Copal but I probably would choose the Compur first. Consider it like buying a Linhof- or Sinar-Select lens... it can't hurt ya.

[Phil Hudson]

I haven't come across a Schneider lens with that high serial in Compur shutter before. It might be at the very tail end of the Compur stock (IIRC you could order Schneider lenses in either Copal or for a premium in Compur) or more likely it is a remount in an older shutter (black face Compur shutters have been around for 20+ years).

The Compur 3 is a very smooth running machine with a faster 1/200 sec speed (versus 1/125 on Copal 3) although the printed aperture scales have a tendency to wear off with use and can't be replaced or interchanged (like Prontor Professional and Copal) to my knowledge......

[Richard K.]

I haven't come across a Schneider lens with that high serial in Compur shutter before. .....

I guess that's part of what I'm wondering about. Did you have a choice of shutters back in 2001 when the lens was made or was this lens remounted? If remounted, I guess there's no problem since Copal and Compur are interchangeable, without shims etc.?

[Phil Hudson]

All the new lenses I have bought in the past 10 years have has Copal shutters but I do have a more recent price list that shows both listed. It's unlikely that you'll have a problem even if remounted (assuming that the shutter is from a 300mm f/5.6) but shims of varying thicknesses are used (or not used) as determined by the manufacturer when they are bench tested.

I guess it is conveivable that small differences in the thickness of Compur and Copal shutters, even between batches of them, along with small variations in the machining of the barrels and lens seating, means that small adjustments are needed to tune the performance of a lens. This is always an unknown factor in buying used lenses - but I've never bought a used lens that was "bad" in that respect.