Conversion to Sinar Auto Shutter

[lbenac]

Hello,

I am awaiting my XPO and started reading a little bit about Sinar shutters.
I am not sure that I get the whole picture so I wanted to ask for some clarification.
For now all the lenses I use are in Supermatic shutters (Ektar 135mm, 207mm and maybe soon 100mm) and Copal (Fujinon-NW 125mm, Nikkor-M 200 and 300mm).
I do not think that any of the Copal shutter would die on me any time soon, but the Supermatic might after 50 years of loyal services.
If I wanted to convert this lenses to a Sinar shutter it would be quite expensive unless of course I am mistaken.

1) Purchase a Sinar auto shutter with cables >$600
2) Have SK Grimes to convert the lens into DB mount lens (Front element/adapter/rear element) $? x3
3) Have SK Grimes to mount the lens on a DB compatible lens board $? x3

My sense is that would set me back $1,500 or more plus the time at SK Grimes.

Am I missing anything or did I get it?

Thank you for your insight.

Cheers,

Luc

[Mark Woods]

Hello Luc,

It's much cheaper and easier than what you outlined. If you have the universal shutter, you don't need to have the lenses DB mounted. I shoot a number of lenses that are in a shutter with the Sinar universal shutter. Use the lens on the Time setting, or set it open. Just open the lens to the F/Stop you want (once you've focused, etc.), close the Sinar shutter, and fire when ready. You don't need both cables, only the shutter release. I bought one on eBay for about $75 that works fine.

Hope this helps.

[LF_rookie_to_be]

What Mark said. Just make sure the rear element of the lens doesn't extend beyond 18mm from the rear side of the lens board. Otherwise the shutter blades will hit the lens, and your expensive Sinar shutter may or may not be fried.

[Ken Lee]

If a lens will fit into a standard Copal shutter (0,1,3) then it will fit into a Sinar DB board, since Sinar DB boards are made in those sizes. For those lenses (your Fujinons and Nikkors) you need to get a board and then adjust the diaphragm to match the focal length. George Brown knows how to do that: he did that for me.

Putting lenses like those into a Sinar Shutter (and being able to taken them out and return them to their original Copal shutters) is a nice option, but not a necessity of course. If those are lenses are on Sinar DB boards, you can operate the camera entirely from the rear like a giant SLR. That's nice but not a requirement of course.

You'll have to ask George or some other expert about the Ektar lenses.

The Sinar Copal Shutter is an initial investment: it saves money when you purchase barrel-mounted lenses, or lenses mounted in DB boards, because they are more affordable. It lets you use barrel-mounted lenses without paying someone like SK Grimes to mount them. For example, I got a 150mm APO Nikkor for $100 and I mounted it on a cardboard lens board. I use it with the Sinar Copal shutter. It's a superb lens for shooting close, and the price was very attractive.

[lbenac]

Thank you all for the answers.
I just realized how little I know about the subject.
It is clear that I already missed the boat on the cost saving aspect but some of the lenses I like might not even exist mounted on Sinar DB board already. Anyway too late :-)

Assumption #1 - The Sinar automatic shutter will do what any shutter does:
1) set the aperture (f4 to f90)
2) set the time (1/60 to 8s)
3) close or open the curtains for image preview
4) and of course fire...
Or is the aperture set on the DB board and the shutter only operate the "curtain"?

Assumption #2 - you can put any lens in front of the shutter provided:
1) its rear cell is less that 18.5mm deep from the back of the lens board (but the closer to the aperture blades the better)
2) it is mounted on a lens board of shape and size that fits the front standard of the XPO or any Sinar camera

Assumption #3 - you can mount the lens cells on a flat board?
This is where I get loss
1) when a lens is mounted on a Copal shutter, there is a certain space between the back of the front cell and the front of the rear cell. I assume that this distance is accounted for in the geometry/formula of the lens and cannot be changed.
So how to you get this distance on a flat Sinar board?
2) likewise the front and rear cells have both male thread that screw in the female thread of the Copal shutter. While the thread are a known size, how do you "couple" the front and rear cell on a flat board?

Based on my lack of knowledge, I should probably stick with mounted lenses :-)

Cheers,

Luc

[pierre506]

Please remember:
Sinar Auto shutter is not Almighty.
Its fastest speed is 1/60 s.

[lbenac]

Please remember:
Sinar Auto shutter is not Almighty.
Its fastest speed is 1/60 s.

Agreed. That said, I do not use flash so I can count on my fingers the times I shot faster than 1/60s.
I am more worried about the report of vibration?

Cheers,

Luc

[Mark Woods]

The shutter (and shims) establish the space between the front lens group and the back group. One doesn't just screw the lens elements onto the board. The DB mount has the capability to correctly place the two groups in relationship to each other.

[lbenac]

The shutter (and shims) establish the space between the front lens group and the back group. One doesn't just screw the lens elements onto the board. The DB mount has the capability to correctly place the two groups in relationship to each other.

So it does require a DB board not a flat board. I will ask the contact recommended by Ken regarding each specific lens.

Cheers,

Luc

[Ken Lee]

I am more worried about the report of vibration

I made a pair of test negatives with a 450mm Fujinon C, using its Copal 1 shutter and then leaving it open and using the Sinar Copal Shutter. I could not detect a difference. Perhaps under a microscope or with a drum-scanner a difference would be evident, but for my purposes the Sinar Copal Shutter has been more than adequate.

Although its top speed is "only" 1/60 second, it was designed for the studio: it and also gives times of 1,2,3,4,6 and 8 seconds.