short on shutters

[Joe Smigiel]

I've recently acquired several lenses with faulty shutters of the same size that have me wondering if a DIY casket set could be made from certain cells.

For example, the old convertible Symmars in focal lengths of 150mm/265mm, 180mm/315mm, and 210mm/370mm apparently all fit into a #1 shutter. I have also seen these lenses for sale mounted in Sinar DB mounts or in barrel for considerably less money than those mounted in shutters like Compurs or Copals.

Is there any difference in mounting threads between the above lens cells intended for #1 shutters vs. Sinar DB mounts or standard barrels? Or, if they can be mixed, is there some combo that would produce 240mm or 300mm to round out the standard progression?

[IanG]

You'd need to check specific lenses because some lenses in Sinar DB mounts aren't standard threads.

The idea of an ad-hoc casket set is not as odd-ball as it might seem as Schneider did sell something like this based on Symmar cells in the past 50's/60's, I can't remember the exact date offhand but it wasn't available/advertised for very long. I thought it was based on 135mm/150mm/180mm cells in a Size #0 shutter but that maybe what I was thinking of trying :) I maybe able to check later today as I know it was in one of my BJP Almanacs.

Ian

[Len Middleton]

Joe,

Wisner had a convertible set he offered at one time; might that be the same thing you are looking at building (abet much less expensive)?

For a copy of an old Wisner catalogue including a listing of the Wisner Convertible Plasmat set, see: http://www.largeformatphotography.info/cameras/wisner-expedition-technical/WisnerCatalog300dpiMonoChrome.pdf

Hope that helps,

Len

[Dan Fromm]

Joe, Mr. Galli has shot with unequal cells from dagor type G-Clarons, says they work well. I b'lieve that the Symmars Ian referred to are also dagor types. Several makers -- Berthiot and Boyer come to mind -- have offered casket sets that contained unequal dagor type cells.

You asked about plasmat types. Some, far from all, plasmat types have been offered as convertibles. I've put unequal plasmat type cells together; they've passed light and formed images.

The focal length of a pair cells depends on their focal length lengths and the spacing. The best way to find out what unequal cells will do for you is to put them together and try them out.

If you have them, try it. If you don't have them, think hard about why manufacturers of modern plasmat types didn't and don't offer casket sets. My guess as to why is that they don't perform as well as users now want them to.

[IanG]

I b'lieve that the Symmars Ian referred to are also dagor types.

I've been busy (making parts to restore two cameras) so haven't checked all the BJP Almanacs yet (I've looked through about half) but I was under the impression the Schneider multi focal lenght set was the series after the Dagor type and was the 60's era splitable Symmars.

It's often forgotten that when Schneider multi coated their lenses (and marked as such) they quietly dropped the convertible aspect. I never met anyone who used the Symmars split for commercial/professional work and the Schneider multi focal lenght set was extremely short lives and is extremely rare second-hand, I did see one on Ebay a few years ago.

So I agree with Dan that while there's an image formed on the screen you'd need to see what you get on film, it's fair to say that with huge improvements in film emulsions peoples expectations became very much higher in the 60's and 70's.

Ian

[domaz]

I've used a lens consisting of a rear element of a 100mm Apo-Sironar-N and a front element from a 150mm Apo-Sironar-N. The overall focal length seems to be about 100mm and the coverage and speed seems to be the same as the specs on a 100mm Apo-Sironar-N. Quality seems quite good. Don't ask me how this lens came to be- it was one of those "bought for the shutter only" deals. I guess the morale of the story is don't be afraid to experiment if you end up with mismatched lens cells.