View Full Version : wanted: diy focal plane shutter

03-02-2012, 11:39 AM
I was given an aerial reconnaissance camera recently. It contains a beast of a lens that I want to build into a camera. The lens is designed to shoot at a fixed focal length of 6 inches on 5.5 inch wide aerial film. The image area is 4.5 x 4.5 inches. The lens is manufactured by Pacific Optical, and it's big and fast - f2.8. The lens has a built in variable aperture. The shutter in the camera is a very complex electro-mechanical focal plane shutter capable of shutter speeds as fast as 1/3000th of a second. Unfortunately, I do not possess the electronic control panel, nor do I have any diagrams or manuals for the camera. I doubt that I will be able to use the shutter in the camera.

Do any of you guys have experience at building a fast focal plane shutter for large format (4x5)? I know that I could probably use the shutter from a Speed Graphic, but I have yet to find one in my price range. I would like to find one without a lens that I could get for not too much money. But it would also be fun to try to build the fastest moving slit shutter that is possible to do yourself.

Design requirements - it has to be able to be fully open for focusing on the ground glass, and it would be nice to be as fast as 1/500th or even 1/1000th of a second.

Any ideas, designs, or commercially available focal plane shutters? Attached files http://f295.f295.org/uploads/aeriallens_122.jpg (http://f295.f295.org/uploads/aeriallens_122.jpg)

03-02-2012, 11:40 AM
Another view of the beast.

Attached files http://f295.f295.org/uploads/aeriallens2_3108.jpg (http://f295.f295.org/uploads/aeriallens2_3108.jpg)

03-02-2012, 11:43 AM
front view

Attached files http://f295.f295.org/uploads/aeriallens3_8884.jpg (http://f295.f295.org/uploads/aeriallens3_8884.jpg)

03-02-2012, 05:23 PM
I have a somewhat similar lens, a Fujinon Xerox lens that lacks any kind of variable aperture (fixed at F/4.5), and which I've used in my 8x10 box camera but, lacking a shutter, I can only use it with paper negatives or Harman direct positive paper under subdued lighting with a lens cap shutter and prolonged exposures.

The shutter being the real problem, and lacking any other option, I've taken to mounting my lens into my 4x5 Speed Graphic, using the curtain shutter. I'd recommend this as the best option. Think David Burnett and his Aero Ektar lens mounted to his Speed Graphic, which he's used for photo-journalism. You could use some of the Harman direct positive paper and get some real nice, narrow depth of focus direct positive fiber prints this way.

I have not come up with a workable design for a reliable DIY focal plane shutter, but the concept is of course like the Speed Graphic, with a traveling slit of variable width. The challenge is the mechanics of such a mechanism shrunk down sufficiently to fit in front of the film plane, within the confines of the camera body, while having the speeds reliable enough for practical use. You may remember the DIY rotary shutter (http://f295.f295.org/uploads/Blah.pl?m-1282773633/) I fit to the front of my 8x10 box camera, it was a mammoth kludge of a shutter, considering it was meant to mimic the functionality of a simple leaf shutter. Hence the reason why I use the Speed Graphic's curtain shutter for these types of lenses.


PS: The lens mounted to my Speed Graphic via a DIY wooden bracket:

The lens:

03-04-2012, 08:10 PM
The camera I'm working on also needs a shutter, and I have been thinking maybe a metal guillotine type shutter could work.

Jimmy G
03-19-2012, 09:43 AM
Any luck with a shutter Earl? Consider using some ND filters and or paper and doing some long exposures. I'd love to see the results from this thing.