Shutter replacement for Color Skopar 105mm 3.5 on Horseman VH 2x3

@DrHSTGonzo · Jul 10, 2020

Hi everyone,
I picked up a Voigtlander Color Skopar 105mm 3.5 in a Synchro-Compur-P (No 0) for my Horseman VH. The shutter has quit working but the optics are in great shape, so I've been looking for a newer Copal No 0 shutter. I've found several Copal 0 shutters on fleabay but am unsure as to which would be best suited. Mainly I'm unsure about the aperture portion of the shutter. Retaining the 3.5 opening is one of the reasons for keeping this lens & installing a new shutter. Is the aperture for a shutter variable to the specific lens? On some of the shutter's for sale there are the aperture markings on the barrel but left blank on the facing (some of the aperture markings only go down F8) - is this left blank to label the corresponding aperture opening to the lens? Or does the marking need to go down to 3.5 to make use of this lens? Thank you for any helpful input - I mostly can find the answers to questions in old forums, but have been wanting to participate more in active forums. Thanks in advance.
Best,
~ Ryan

shutterfinger · Jul 10, 2020

Aperture is a function of the lens in use and its entrance pupil.
Aperture is lens measured focal length divided by the diameter of the aperture opening as viewed through the front of the lens.
As long as the cell thread, cell opening and spacing between the front and rear cells are correct then the shutter will work. A new aperture scale will need to be made or possibly the one from your Compur will fit the Copal.

Dan Fromm · Jul 10, 2020

Cells that work properly in a Compur #0 will work properly in a Copal #0.

If you swap the cells into a replacement shutter, you'll have to make an aperture scale that's correct for the lens. If I recall correctly -- I'm feeling lazy, don't want to waddle upstairs to check -- Copal #0s all have linear aperture scales. This means that the distance -- angular and linear measured around or across the shutter's rim -- between stops is constant. Also, IIRC, the distance between stops is 4.5 mm. You can check both assertions when you have a Copal #0 with aperture scale in hand.

When you start to make an aperture scale, put the f/3.5 mark where the pointer is the aperture indicator points when, with the front cell in the shutter, the diaphragm leaves just disappear/just begin to be visible, looking at the shutter from the front.

ic-racer · Jul 10, 2020

The shutter has quit working

I'd try to repair the shutter.

@DrHSTGonzo · Jul 10, 2020

Thanks everyone for your helpful responses!

shutterfinger said:
As long as the cell thread, cell opening and spacing between the front and rear cells are correct then the shutter will work. A new aperture scale will need to be made or possibly the one from your Compur will fit the Copal.

Okay great, I was assuming that was the case but you know what they say assumptions.

ic-racer said:
I'd try to repair the shutter.

It may be repairable, the only speed it will remain cocked is on bulb. Otherwise the shutter speeds seem accurate & the catch for holding it open to focus still works. Does it sound like a relatively simple fix? I have not worked on these before so it would probably have to be sent off. Perhaps I could do the repairs myself, but a newer shutter would also allow me to use a cable release.

shutterfinger · Jul 10, 2020

A Compur shutter is a rough way to learn shutter repair on. They are complicated compared to Copal. It just needs a CLA. I can do it as can others on this site and several good repair shops.
https://learncamerarepair.com/productlist.php?category=2&secondary=20

ic-racer · Jul 10, 2020

You should be able to get a new 105mm lens in a good working shutter for less than a new shutter with no glass.

@DrHSTGonzo · Jul 11, 2020

I have been considering that option as well ic-racer. Copal shutter's are going for around $100 - $125 + shipping. I could pick up a Topcar lens for a little more, but how do the optics on a Professional 3.5, Super 4.5 or ER 5.6 105mm lens compare to the Color Skopar? The few rolls I took with the Skopar turned out quite pleasing. But If I bought another lens/shutter combo I could always attach the Skopar Cells to the shutter & be able to compare the results no? In the meantime I may remove the 75mm Caltar II 6.8 lens from the Copal shutter I just picked up & see how it looks/works.

Dan Fromm · Jul 11, 2020

@DrHSTGonzo said:
I could pick up a Topcar lens for a little more, but how do the optics on a Professional 3.5, Super 4.5 or ER 5.6 105mm lens compare to the Color Skopar?

The Topcors are sharper and have better coverage. The /3.5 is a tessar type, the /4.5 has six air-spaced elements. I'm fascinated by the f/4.5 but am more than full up with normal lenses for 2x3. I'm not sure you can get an /4.5 for little more than a naked Copal #0.

However, I'm speaking from general principles, not from personal experience. I don't have a 105/3.5 Color Skopar.

I do have an 80/3.5 Color Skopar on a Perkeo II. I've never got a satisfactorily sharp shot from it. Satisfactory, yes, sharp, no. I've discussed this with the late Charlie Barringer (co-author of the Zeiss-Ikon Compendium, google him), who had a Perkeo II that shot no better than mine. And I've discussed this with Eric Beltrando (visit his site dioptrique.info), who tells me that the Color Skopar is not a particularly good Tessar type.

@DrHSTGonzo · Jul 11, 2020

Dan Fromm said:
The Topcors are sharper and have better coverage. The /3.5 is a tessar type, the /4.5 has six air-spaced elements.

Thanks Dan for the info, I don't mind spending a little more to get a sharper lens. Especially since it's for the 2x3 negative. I would like the ability for movement's, from what I've read the 105 professional is limited in that regards. I appreciate the helpful input & research.

ic-racer · Jul 11, 2020

I use the f3.5 105mm mostly with the rangefinder, where I like the extra speed and lighter weight and I'm not using movements. That lens also folds up in the camera. . The f4.5 105mm is the largest lens in the Horseman Technical system. Its main advantage is that it is very sharp right up to the edge of the image circle. The image circle is a good match for the movements of the camera.
The f4.5 lens is noteworthy for its massive rear elements. Maybe Dan can comment on that design feature, for example how it looks like a backward version of the Nikon W 100/5.6 with similar image circle

Dan Fromm · Jul 11, 2020

Ic, I don't know where I got the idea that the 105/4.5 Horseman has six air-spaced elements. The picture you posted shows a sort of plasmat type. The ones I've seen offered are engraved 158 mm. That's the diameter of the circle covered.

The 105/3.5s I've seen are engraved 125 mm.

ic-racer · Jul 11, 2020

Horseman and Nikon have some similar lens. The minimal coverage Horseman f3.5 105 3/4 is like the Nikkor 105 3.5 3/4 and the wide-coverage Horseman f4.5 105 6/4 is like the Nikkor-W f5.6 100mm 6/4 but in reverse. In the Nikkor, the large component is in front, whereas the Horseman the large component is in the rear. (The diagram in post #11- above the large component is toward the film.)

@DrHSTGonzo · Jul 11, 2020

ic-racer said:
Horseman and Nikon have some similar lens.

I knew different manufactures use similar design feature's, it's interesting to learn how they intersect. While looking for lenses I came across a Fuijinon W 105/5.6, under the detail info the design is listed as Series: Rodenstock Sironar N. Guessing they are of similar design?
The Caltar II N 75/6.8 I ordered was listed as the same design as Rodenstock Grandagon-N.

Dan Fromm · Jul 12, 2020

Most modern LF lenses that aren't telephotos or wide angles are plasmat types. Most, not all.

Most current, well, not too ancient, wide angle lenses for LF are of two design types, six elements/four groups like the f/8 Super Angulon and eight elements/four groups like the f/5.6 Super Angulon. Most, not all, there are exceptions. As far as I know the first 6/4 to market was the f/8 Super Angulon. The first 8/4 to market was probably the 58/5.6 Grandagon, unless it was the f/5.6 Super Angulon.

Calumet didn't manufacture lenses. They bought lenses and had them badged Caltar. II Ns are rebadged Grandagon-Ns made by Rodenstock. Not the same design, the same lens. Other Caltars were made by Ilex, Topcon and Schneider.

ic-racer · Jul 12, 2020

Yes, some Caltars and Topcors share identical glass in different housings. Important for Horseman users is the f5.6 90mm lens. In the Caltar housing, the lens won't fit on the camera. The Horseman branded housing allows for a protective ring to be removed, thus allowing the lens to be mounted through the limiting hole in the front standard.
The picture shows a lens group with separation from a Horseman branded lens being swapped with mint condition glass from a Caltar lens.

Dan Fromm · Jul 12, 2020

Ic, I understand that the Caltar's rear cell won't pass through the front standard's lens throat. I don't understand it can't be unscrewed from the shutter/board assembly and reattached through the rear of the camera. Will it not fit in the bellows?

I ask because I have a couple of w/a lenses that have to be mounted on my 2x3 Graphics that way and one w/a lens that fouls the bellows.

Shutter replacement for Color Skopar 105mm 3.5 on Horseman VH 2x3

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