Sinar Auto-Aperture Shutter

[Scott Davis]

What's the diameter of the shutter opening in a Sinar Shutter? I have a lens I'd like to use with one so I can sync a flash with it, but I don't know if it would vignette the lens.

[Keith Pitman]

I measured 82mm at the front of the opening and 75mm at the back. I don't know if different shutters will have different measurements. There have been several versions.

[Scott Davis]

I measured 82mm at the front of the opening and 75mm at the back. I don't know if different shutters will have different measurements. There have been several versions.

Thanks! It gives me a starting ballpark. I know that will work for at least one of the lenses I'm looking at. But I might have to rig some kind of spacer as their rear element sticks out behind the lens board by more than a few millimeters.

[mhayashi]

Scott, my thread would help with a similar issue.
https://www.largeformatphotography.i...-swiss-cameras

My solution is making a custom mounting ring.
Your solution also depends on whether you mount the lens in the normal direction to the sinar shutter,
or in the reverse like my example which has a less clearance between the lensboard and the shutter blades.

[Daniel Unkefer]

Peco Profia to Norma Shutter Adapter by Nokton48, on Flickr

A friend (he's a clockmaker/camera tech) made me this Norma Shutter to Plaubel Peco Profia Adapter which works great. Some day I will paint it Norma green.

[Bernice Loui]

Rear lens element does not fit into the front of the Sinar shutter? Done this many, many times works no problems.


Basically make a collar out of aluminum to move the lens position away from front opening of the Sinar shutter.



Bernice

Thanks! It gives me a starting ballpark. I know that will work for at least one of the lenses I'm looking at. But I might have to rig some kind of spacer as their rear element sticks out behind the lens board by more than a few millimeters.

[Keith Pitman]

Here’s another one: The aluminum ring was machined by a friend. It was necessary because the back of this lens would have extended into the Sinar shutter. The Sinar shutter is mounted in reversed position using a Luland adapter so it would fit on the Chamonix camera.

[Daniel Unkefer]

I should mention that Sinar mentions in the Norma Shutter Manual that the rear cell of the lens should ideally be within 1mm of the front of the shutter blades.

In this way mechanical vignetting can be avoided in some situations/certain lenses. I have always tried to adhere to this, of course impossible if the lens diameter is bigger than the shutter opening

[peter brooks]

If you don't have access to metal working facilities you can always use wood and a large hole saw. This is 25mm (1") plywood, you could layer thinner pieces to get the correct thickness.

You would need a robust drill press, plenty of patience, and to clamp everything very securely. A fire extinguisher might come in handy on thicker pieces.



There are also all sorts of Sinar 'top hat' boards that can be altered to suit.

[Scott Davis]

If you don't have access to metal working facilities you can always use wood and a large hole saw. This is 25mm (1") plywood, you could layer thinner pieces to get the correct thickness.

You would need a robust drill press, plenty of patience, and to clamp everything very securely. A fire extinguisher might come in handy on thicker pieces.



There are also all sorts of Sinar 'top hat' boards that can be altered to suit.

The problem is that I no longer have a drill press nor do I have easy access to one (I don't think the woodworking club in my area is open at this time). I'm looking into 3D printing as an option. Still doing some investigating- I've had some wildly varying recommendations on how to approach it so I'm still just as confused as I was before.