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jp
24-Jun-2010, 14:14
I'm evaluating my options for a shutter for a large flanged soft focus lens roughly 5" rear glass, 5.5" front glass diameter.

I would like some variability of speeds for outdoor use, and flash sync would be a plus for indoor portrait use (I'm not into hot lights, and we don't have much natural light here). Cost is of course important, but not the only consideration.

So far my options seem to be:

* Double-darkslide shutter. Cheapest, but no flash sync and kinda awkward as I'd need 2 8x10 darkslides in my hand.

* Packard shutter; would be monstrous (8.5" square) and $5xx dollars. Would provide one shutter speed?

* Homemade Guillotine shutter as recently shown on here by a Japanese constructor. Inexpensive. Flash sync could be added by putting a NC microswitch abutting the slide, or via a reed relay and magnet mounted on the opening. Downside; physical size; I'd be looking at something about 18" tall. It might get in the way of aperture adjustment.

* Gut a Speed Graphic and put it between two lensboards for the focal plane shutter. Cheap enough ; maybe $100-200? Lots of shutter speed options, flash sync depending on the model chosen. Downsides; might need to brace the front standard. Would restrict light slightly at the top and bottom where the shutter is not quite as big as the rear glass of the lens. (4x5 opening instead of 5x5 opening) Would this alter the image quality any at wide open by in effect by probably creating an odd shaped aperture?

Am I overlooking any options? What would you choose?

Dan Fromm
24-Jun-2010, 14:25
If you want timed exposures, the Speed Graphic approach will probably work. If you want to sync with electronic flash it won't; this because the only speed at which the entire gate is exposed at the same time is "T."

You may want to consider a big leaf shutter. FWIW, I have a Compound #5 in the drawer. Max aperture 64.5 mm. Fastest speed 1/50. Not too useful for flash without very slow film, tiny aperture, or heavy ND filtration. It might be possible, but not cheap, to remount y'r lens from barrel to a large Alphax, Betax, Compound, or Ilex but all of these have relatively slow fastest speeds.

Jim Galli
24-Jun-2010, 14:34
I don't think sync is an option on the guillotine. They use a continuously smaller slit opening to get the different speeds possible. If sync is important the Packard is likely your best option. They appear cumbersome but they are light and work well. See my Packard Shutter (http://tonopahpictures.0catch.com/Article_About_Packard_Shutters.html) page for how to get everything from 1/10th (giant ones are less fast than smaller ones) to multi seconds. I may have an extra used giant one laying around here somewhere.

James E Galvin
24-Jun-2010, 14:42
I have seen a very large shutter for an aerial camera, for instance for the 40" f/8 lens. It might have been 5" diameter. Be careful with such a shutter, stainless steel blades and a big spring, could cut your finger off. Somebody used one for trimming cigars.

jp
25-Jun-2010, 10:34
Did a bit more research. Dan is right about the speed graphic, it's focal plane shutter only works with flash bulbs as the slit as "T" is the only setting that exposes the entire film at once. I was hoping some of the slowest of timed speeds would work, but it's not so.

I could make a guillotine sync if the slowest speed blade opening is as large as the lens.

IanG
25-Jun-2010, 13:16
There were some large Thornton Pickard shutters, they only have one slit and it is fully open. exposing the entire frame at on point during an exposure. Speed is only governed by tension.

While these larger ones were often designed for rear mounting between camera and back they could like the smaller TP shutters be front mounted on the lens or between lens & standard. Rigging up synch would be very simple.

Also the bellows type studio shutters made by the Altrincham Rubber company would work with flash sync and would be even easier to synch as well. Kodak also sold these shutters in the UK. I copied a page from a Kodak 1940 Catalogue I'll post images tomorrow,

Ian

Steven Tribe
25-Jun-2010, 16:55
Norka shutters were made in up to 16cm lens opening, Guerry up to 14.5cm, and Grundner (which I think is the same system as Ian's Altrincham (sic?) Rubber) also up to 16cm. None of the front T-P type curtain shutters seem to have been made wider than 10cm. Norka and Grundner are easily made OK for flash sync.

IanG
25-Jun-2010, 22:35
The Altrincham Rubber Co (A.W.S Sanderson) made very similar shutters to Thornton Pickard, also based in the same town, Altrincham just outside Manchester. There may have been some connection.

The bellows studio shutter may not be fast enough though. See below from the Kodak catalogue,

Ian

Steven Tribe
26-Jun-2010, 02:02
Yes, this is exactly like the Grundner shutter which was made from at least 1910!
Mine still works perfectly. The top speed is about 1/10 sec. Fitting can be difficult as it sticks out behind by the radius dimension when closed. Thus the 16cm size opening needs almost 10cm of camera bellows space behind the mounting plate. Unlike the Guerry/Norka "barndoor" shutter type (see homemade project mentioned by Gandolfi earlier this year) the "bellows/hemisphere" do not seem suitable for modern replicating.