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View Full Version : Which would you buy, Synchro Compur or Copal



Ed Bray
20-May-2012, 14:45
If you have a choice of the same lens, in the same condition, and a similar age and selling for a similar price, which would you buy?

Would you go for the slightly newer Copal shutter or the slightly older Synchro Compur with it's extra blades in the iris (which purportedly gives better bokeh)?

Just curious as I am looking at buying a 240mm Symmar S f5.6 and the supplier has two in stock, one in a Copal shutter and the other in a Synchro Compur, price is very similar as is the condition and the serial numbers.

BrianShaw
20-May-2012, 14:55
Either, with no preference except condition.

Old-N-Feeble
20-May-2012, 14:58
FWIW, I'm in the process of buying some old Compur shutters (very round apertures) to test my late-model lenses with. From what I've seen, after much research, the shape of the iris has as much to do with "blur quality" as lens design. If I like what I see I'll have the shutters CLA'ed, new aperture scales made, and will mothball the new Copal shutters. That's a BIG "IF" though and YMMV.

Leigh
21-May-2012, 07:00
The Compur shutters are of much more robust design and construction than the Copals.

Of course, they're also older, since they've been out of production for some years now, and Copals are current production.

Copals are excellent reliable shutters, but if I wanted a shutter that would outlast me, I'd get a Compur.

Some people worry about getting them repaired, but there are still lots of parts available. I have a large stock of parts.

- Leigh

E. von Hoegh
21-May-2012, 07:02
Compur.

Frank Petronio
21-May-2012, 07:33
I prefer Compurs but I think they require more frequent maintenance than Copals. Like a fine German automobile versus a Toyota ;-p

Ed Bray
21-May-2012, 07:37
That's all good, I was a little concerned about the bokeh issue, and all being similar, age, price and condition I would personally have expected the Compur to give better Bokeh with it's multiple bladed iris.

The two lenses I was looking at were both Schneider 240mm f5.6 Symmar S in Exc++ condition, one in a Copal 3 shutter ser 14,300,000 for 225 and one in slightly better condition in a Compur 3 ser 13,800,000 for 240.

Another reason for me to be happier with the one in the Compur, is that it comes in a Sinar lensboard, so even more reason to for me to be happy.

As both lenses are exactly the same I would expect the bokeh to be better from the shutter wih the more rounded aperture blades.

E. von Hoegh
21-May-2012, 07:41
That's all good, I was a little concerned about the bokeh issue, and all being similar, age, price and condition I would personally have expected the Compur to give better Bokeh with it's multiple bladed iris.

The two lenses I was looking at were both Schneider 240mm f5.6 Symmar S in Exc++ condition, one in a Copal 3 shutter ser 14,300,000 for 225 and one in slightly better condition in a Compur 3 ser 13,800,000 for 240.

Another reason for me to be happier with the one in the Compur, is that it comes in a Sinar lensboard, so even more reason to for me to be happy.

As both lenses are exactly the same I would expect the bokeh to be better from the shutter wih the more rounded aperture blades.
The number and shape of aperture blades will influence the shape of the out of focus highlights. Nothing else.

E. von Hoegh
21-May-2012, 07:42
I prefer Compurs but I think they require more frequent maintenance than Copals. Like a fine German automobile versus a Toyota ;-p

And like fine German cars, the frequency of maintenance has much to do with how that maintenance is performed.

Ed Bray
21-May-2012, 07:50
[QUOTE=E. von Hoegh;889875]The number and shape of aperture blades will influence the shape of the out of focus highlights. Nothing else.[quote]

Quite, and that can make quite a difference at wide apertures on a portrait lens.

Ivan J. Eberle
21-May-2012, 09:57
Number of blades also influences how sun stars and specular highlights are rendered.

IanG
21-May-2012, 10:05
The early rimset Compur, Rapid Compur and then Synchro Compur are by far my most reliable shutters, I find the earlier dial set Compurs accurate as well but they unfortunately weren't made to the modern size standards.

Ian

Lynn Jones
21-May-2012, 13:16
I don't know about right now but after WWII, Compurs failed at very high rates, 10% or more in warranty. Most of my heavy experience with LF lenses was 60's, 70's, and 80's. The most reliable shutters I have ever seen were Seikosha, followed by Copal, and Rapax. Late Ilex shutters (mid 1960's through early 80's) were very reliable until the company started to fail due to the loss of the brilliant Pres. M. Kiner. My considerable experience with lenses and shutters tells me than ALL self cocking shutters will fail early in their lives.

Lynn

domaz
21-May-2012, 15:51
Don't forget about cold weather performance when testing/examining shutters. I had a Synchro Compur stop functioning in cold weather, while my newer Copal is fine. Does this mean the Copal is better? Who knows, but it does mean that you should keep this in mind when buying and do a test (put it in a freezer in a plastic bag) before using in the field.

Kevin Crisp
21-May-2012, 15:53
Flutots will tell you Compur parts are a problem since they were discontinued. For that reason I'd prefer Copal, but I've never had one that she can't get right without new parts.

Leigh
21-May-2012, 16:06
I had a Synchro Compur stop functioning in cold weather, while my newer Copal is fine. Does this mean the Copal is better?
No. It means somebody put the wrong lubricant in the Compur escapement.
The Copal probably had the original factory lube, which I expect is designed for a wide temperature range.

There are a few different lubricants suitable for shutters, some of which work better at low temperatures.

We used to set up Nikon F2 cameras for use in Antarctica using special low-temperature lubricants.
I did that to my wife's F2 when she went to Antarctica. (You best do it right when SWMBO is involved!)

- Leigh

Frank Petronio
21-May-2012, 17:32
The number and shape of aperture blades will influence the shape of the out of focus highlights. Nothing else.

Yeah I tend to call all that bullshit bokeh myself, no matter what the technical definitions are. If I shoot into the trees and sun, I want circles - not hexes. Bokeh smokeh otherwise.

Of course if you shoot a modern shutter with only seven blades wide open, it is a round aperture.

BTW later Compurs had penta and hex openings, bummer.

Old-N-Feeble
21-May-2012, 17:36
No BS, Frank. Not in my opinion. I've researched this quite a bit and, although I've little understanding of lens design (controlled chromatic aberration), there's no denying the advantage of apertures that are more round. But I've some specific image qualities that I'm looking for.

Any aperture wide open is definitely "round". I don't usually shoot wide open.

Frank Petronio
21-May-2012, 17:48
I don't mean BS I guess, I've had the Aero and the Verito and go out of my way for round apertures too. Plus I fool around with exotic 35mm lenses sometimes. But I don't think most photographers know what good or bad bokeh is - look at how they gush over Aero Ektars just because they are short depth of field photos. Or get all excited about swirling backgrounds and other cheap party tricks like that ;-p

I gave up worrying about it, I just don't like cheap hexagonal sunspots in my photos, otherwise the subtleties are lost on me.

Old-N-Feeble
21-May-2012, 18:03
Frank... I agree. All I intended to state is that round apertures seem to make prettier images in the out-of-focus regions... as do some types of optical designs. Everything is a compromise but angular apertures (stop signs) are not one of those "technically necessary" compromises... other than cheap offerings. It's a compromise by the latest shutter manufacturers being -- "CHEAP". ;)

Are we going through yet another Renaissance?

Corran
21-May-2012, 18:35
I prefer my Copals because they have 7 straight blades so they make specular highlights and the sun have nice 14-bladed stars. This assumes I have everything in focus.

When I've gone for shorter DOF in my LF stuff, so far, I haven't seen any really ugly bokeh caused by aperture shape. I think the blur characteristics in these cases have tended to be acquired by the lens design. Now, in my Nikon 35mm system, the older AF-D lenses often have 7-bladed apertures, and those would in fact show ugly bokeh effects from the shape of the iris. But I feel like that's more due to the larger DOF of the smaller format. But I could be wrong.

I honestly would like to have a complete set of lenses on my 35mm DSLR with nice round apertures for portraits/people and one set with 7 or 9 bladed diaphragms for landscapes with specular highlights or the sun. If I was that crazy anyway (of course usually I use primes for landscapes and zooms for people so it all works out).