Help: Seiko shutter hole diameter for lensboard fujinon 250 f/6.7

I can't find any information on the diameter hole I need drilled to mount this lens on a board. It is an older Seiko shutter marked LS24 for a Fujinon 250 f/6.7; more specifically this lens for reference:

http://www.ebay.com/itm/110907896470...84.m1497.l2649

I would appreciate any help on this so I can use it asap!

Have you applied a ruler to the threaded part of the shutter?

I'm not being snarky... only trying to sincerely help.

No Brian, I don't have this lens yet, it is on the way from Japan. I wanted to get the board done asap, so I was hoping someone had one and could help.

Thanks for the idea though.

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Originally Posted by David Brunell

No Brian, I don't have this lens yet, it is on the way from Japan. I wanted to get the board done asap, so I was hoping someone had one and could help.

Thanks for the idea though.

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Measure it and update the "lensboard hole size" document on the main page :)

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Originally Posted by ic-racer

Measure it and update the "lensboard hole size" document on the main page :)

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Will do.

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Originally Posted by BrianShaw

Have you applied a ruler to the threaded part of the shutter?

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On shutters that use a retaining ring, the mounting hole diameter is significantly larger
than the major diameter of the thread.

The retaining ring has a shoulder that protrudes into the hole.

- Leigh

Seiko 0 shutters are the same diameter as Copal 0, so I would think the 250 6.7 is in a Seiko 1 and is the same diameter as a Copal 1 .

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Originally Posted by Neal Chaves

Seiko 0 shutters are the same diameter as Copal 0, so I would think the 250 6.7 is in a Seiko 1 and is the same diameter as a Copal 1 .

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Not all of them! The shutter for the Fuji 250/6.7 needs a slightly larger hole than a Copal 1. I don't have this lens now, so can't give any exact figures.

Kumar

I have a Linhof type board drilled for a Seiko.....it wasn't the same as my Copal spec boards...long ago sold the lens but I still have the board.. pm me!

Just a bump. I recently got a Fujinon WS 250 6.7 from the bay. I'm curious what size of the hole needed for lensboard since the shutter is Seiko 1 i think. Anyone?

Thank you!

I don't have the flange/retaining ring for mine so I can only give you the thread diameters. A Copal/Compur 1 has a 39mm flange thread while the Seiko shutter on mine has a 46mm flange thread. I'm guessing you would need a 50mm hole in your lens board.

Note that the front cell on a Copal 1 is a 40mm thread while the rear is a 36mm thread. On the 250/6.7 WS both the front and rear cells have a 42mm thread. While I'm at it, the largest aperture diameter is 30mm and the length between mount faces is 26mm. It is a decidedly non standard shutter, but more like a large Copal 1 than a small Compur 2 or 3.

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Originally Posted by tenderobject

Just a bump. I recently got a Fujinon WS 250 6.7 from the bay. I'm curious what size of the hole needed for lensboard since the shutter is Seiko 1 i think. Anyone?

Thank you!

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A Seiko 1 shutter will fit in a Copal#1 lens board hole. At least mine does.

thanks paul. i will look for more info. i need exact diameter because i'm planning to buy one for my KMV which is abit expensive for error! :)

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Originally Posted by Paul Ewins

I don't have the flange/retaining ring for mine so I can only give you the thread diameters. A Copal/Compur 1 has a 39mm flange thread while the Seiko shutter on mine has a 46mm flange thread. I'm guessing you would need a 50mm hole in your lens board.

Note that the front cell on a Copal 1 is a 40mm thread while the rear is a 36mm thread. On the 250/6.7 WS both the front and rear cells have a 42mm thread. While I'm at it, the largest aperture diameter is 30mm and the length between mount faces is 26mm. It is a decidedly non standard shutter, but more like a large Copal 1 than a small Compur 2 or 3.

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It might be best to wait for the lens to turn up and then measure it just in case there are two versions of the lens. I'm confident that my one is not a Seiko #1 but that doesn't mean that the 250/6.7 wasn't redesigned to fit in a regular #1 shutter. The aperture diameter of 30mm is the same as in a #1 shutter, so it would still have an f6.7 max aperture. When the Compound #4 shutters went out of production Schneider was able to rejig the 360/5.6 Symmar to fit into the smaller Copal 3 where it became the 355/6.8 Symmar. Apart from the max aperture it was the same lens, both versions had an actual f/l of 358mm.

thank you paul. i think that would be better. my lens is in transit now. i will try to have my friend measure the diameter of the lensboard that comes with it.

my fujinon 250 is WS not the usual W. not sure what is the difference between these versions.. anyone can chime in?

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Originally Posted by Paul Ewins

It might be best to wait for the lens to turn up and then measure it just in case there are two versions of the lens. I'm confident that my one is not a Seiko #1 but that doesn't mean that the 250/6.7 wasn't redesigned to fit in a regular #1 shutter. The aperture diameter of 30mm is the same as in a #1 shutter, so it would still have an f6.7 max aperture. When the Compound #4 shutters went out of production Schneider was able to rejig the 360/5.6 Symmar to fit into the smaller Copal 3 where it became the 355/6.8 Symmar. Apart from the max aperture it was the same lens, both versions had an actual f/l of 358mm.

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Here is the answer few years later: The diameter of the hole of the lens board for the Seiko shutter that comes with the Fujinon WS 250mm f6.7 is 50mm, which very approximately matches the hole required for the Ilex shutter (50.52mm) that usually came with the Kodak lenses. You are welcome.

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Originally Posted by B.S.Kumar

Not all of them! The shutter for the Fuji 250/6.7 needs a slightly larger hole than a Copal 1. I don't have this lens now, so can't give any exact figures.

Kumar

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EXACTLY, the shutter for the Fujinon WS 250/6.7 is a bit larger than Copal #1. You cannot put it in a Copal 1. However, the Fujinon W 250/6.7 does come in a Copal 1. I guess the S stands for SEIKO.

Interesting...

what year that shutter is ?

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Originally Posted by Pere Casals

Interesting...

what year that shutter is ?

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I don't know. I sent my shutter to have a CLA, due to lagging slow speeds. It should be coming back in a week.

It was still WS in the Copal shutter model.

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Originally Posted by Chuck Pere

It was still WS in the Copal shutter model.

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. Interesting, live and learn. I tried to put my WS in a Copal 1 and did not fit. My WS is couple of millimeters wider to fit. I guess they made several types. According to the D.O. Industries, it is possible that the latest version (after return) could have been placed in a Copal 1.

Here is a copy of the the W only:

I happened to find a Fujinon lens in one of these Seiko shutters that looks like a #1 but isn't, and I took some measurements, in the hope that it helps future perplexed people.

The lens is a Fujinon-WS 210/5.6 (older kind with inside writing), not the 250/6.7, and it's in a Seiko shutter that is the same body diameter as a Copal #1, but both the mount threads and the lens threads are different. It had no retaining ring, so this could have been a PITA, but turns out the mount thread is M46x0.75, which is the same size as a 46mm filter. So I got a 49->46mm step-down ring to make a retaining ring. This screws right on, but is too deep to clear the rear element, so I'll have to file it down a little. I'm sure skgrimes.com could make a true retaining ring for this size.

Dimensions comparing Seiko (measured) to Copal #1 (from skgrimes table):

Dimension	(Fuji)Seiko	Copal #1
front thread	M42-0.75	M40-0.75
back thread	M42-0.75	M36-0.75
thickness	~21.8 mm	20 mm
front to shutter	~12.2 mm	10.75 mm
mount thread	M46-0.75	M39-0.75
lensboard hole	~48 mm or larger	41.6 mm
iris diam	30 mm	30 mm
body diameter	73 mm	73 mm

Here's a pair of photos where I compare it (left) to a Nikkor 210/5.6 in a standard Copal #1 shutter (right). The photos have some distortion, but you can see how the Fuji lens has larger elements that fit into the larger threads of the Seiko shutter.

Attachment 195389

Attachment 195390