Sinar DB shutter systems: Need some help

[Daniel Stone]

hey guys,

I've been gearing up to sell my 8x10 camera(which is still listed in the classifieds btw).

but I've been thinking about building a new camera, of my own design.

having seen that some people have adapted the sinar db shutter system to the front standard, I thought this a nifty idea 1. because the lenses are quite plentiful, and 2. they're pretty cheap compared to in-shutter lenses, even the same type of lens cells

so, having given my fingers, and my brain some excercise over the last hour or so before writing this, I've come to realize there is a number of different variants to these shutters. Some have digital-type contacts(gold plated I'd assume), some don't. I'm looking to use this in the field, so reliability is key, and I'd like to use a wide assortment of lenses, from 90mm for the 4x5 red. back on the camera, to a 360 or longer for the 8x10(what's the longest db-mounted lens you've seen?)

so anyhow, my point is this: what variations of shutters are out there, how reliable are these things(one piece of sand/grit fudge the whole thing up, etc...).

I'm a college student, but I come from a family of engineers, so rigging this shutter system to the camera isn't the hard part, but finding the right one for the right lenses is what I'm after.

thanks

-Dan

[Steven Tribe]

I think there are two basic models.
The first is without the adjustment of iris - usually called the the Sinar Norma sinar copal. The second is with the side adjustment thingey (A system I have never used!) for iris control. A believe there are a couple of generations of this type.
I'm into old lenses and have an adaption system were I can use these on a sinar norma and a cambo master (larger lens board).

But if you are into modern lenses - these are nearly always with Copal 1/3 or Prontor Prof. And the prices of these are very low as there are multitudes of them on the market. So, unless you are bent towards oldies, it doesn't make sense.

Sinar copals have a good reputation - just remember to withdraw the leaves into the body of the shutter for transport/fitting adaptors etc. When buying, remember the shutter cable throw is very loooong so only original sinar/copal cables work. Expensive to buy separately.

[uhner]

Take a look at this thread: http://www.largeformatphotography.in...ighlight=sinar

[Joshua Dunn]

I use the Sinar shutter on my F2 and P but not with any DB lenses. I have mounted on either a flat board or one with a cone that will allow the entire lens to be forward of the lens board. This is important because DB boards are designed to be used in the same manner, with all of the elements being forward of the lens board itself. This is only for clearance reasons, it actually makes front tilts and shift a little more challenging.

Mostly I have old brass lenses and Apo Ronars that I use in this configuration, ranging in focal lengths from 90mm to 600mm. The largest DB mounted lenses I have seen are 480mm. But the important part is this; all of my lenses (at least ones I wish to stop down) have internal apertures in them. I don’t use the Sinar shutter to stop down the lens, only to control the time of the exposure.

Hopefully the images below explain it better than I can in words. The first image is of the shutter itself so you have an idea of how little clearance you are working with. Images two and three are of a brass lens (around 8”) and images four and five (see the bext post, I can only upload a maximum of four images) are a 600mm Apo Ronar. Obviously this better illustrates how you have to keep the entire lens in front of the shutter. In the case of the 600mm Apo Ronar this makes for a very awkward setup but it does work.

Just out of curiosity why make a camera when there are so many capable used ones on the market? No camera does everything but you can buy ones relatively cheap that come close. I am actually having my 5x7 back “modified” to work with a K.B. Canham 6x17 roll film holder rather than buying a whole new camera.

[Joshua Dunn]

Additional Pics of the 600mm Apo Ronar

[mhulsman]

Daniel,

I have mounted a shutter in front of my B&J 8x10.
Make sure youre front standard can make enough movements after the shutter is mounted.
The shuttercable can stuck against the front standard and than limit the movements.

[bbauer]

one advantage of using the sinar shutter for multiple lenses is that you've only got the one shutter to keep track of actual speeds vs. what's on the dial, especially if you're shooting chromes.

[Ken Lee]

It has many advantages. One of them is that it is self-cocking. Another is that a small red pin is visibly raised, when the shutter is open. This helps prevent you from pulling back the dark-slide while the lens is open, and you can see it from behind the camera, whether your ground-glass has corners or not.

[David McNiven]

Hi Daniel, I use Sinar Copal auto shutters on Sinars and use DB mount lenses among others.
The shutter fits between the front standard and the bellows, the lens board fits to the front of the front standard as normal. 4.5 and 5.6 models of shutter are available. Electronic versions too.
The DB mount has a diaphragm cammed for its specific lens and the shutter unit drives it by a pin moving through a 1/4 circle (more on the 4.5, rarer version). Aperture control is on the shutter.
A cable is available connecting a Sinar back to the shutter - inserting a DDS closes the blades & primes the shutter to be cocked & released by the release cable. You don't have to use this linkage though. Flash socket is not the usual PC fitting.
Release cables are hard to find and expensive but essential - normal ones won't work.
Adapters are available to use the shutter with other cameras but if you're an engineer...
Because of their size a little sand doesn't stop them, gravel might. Also removing 4 screws each side lets you clean the whole thing.
They don't feel or sound much like normal shutters - be prepared for a shock!
Lots of info is available online at http://www.image2output-support.com/sinar/
Blades are vulnerable and do need to be retracted when not in use.

[David McNiven]

Oh yes, meant to mention this.
The Sinar front standard's "septum" separates the shutter from the lens board by 1.8mm.
For the DB lenses to have the diaphragm controlled from the shutter any adapter should meet this condition. Obviously a Sinar standard or its frame would make a good front standard for your camera.
Reversing the shutter is possible if nothing projects behind the lens board and you don't need the DB control.