Want to Buy Seiko #1 f/5.6 shutter

[pdccamerqs]

HI all,

I am looking for a working Seiko #1 shutter set up for an f/5.6 lens - preferably unmounted, with mounting ring so it could be mounted in a Linhof-style board or similar. If you've got one you would like to part with, please PM me with a price and shipping info to 06260 in the USA, etc.

Thanks for reading!

Paul

 

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[reddesert]

I suggest a couple of words of caution:
- LF shutters don't come set up just for a particular max f-stop. They might have a aperture plate engraved for that max f-stop, but that will depend on the lens. One might find #1 shutters used for a 210/5.6 and a 240/5.6, but these will have somewhat different aperture number plates, even if the threads are the same.
- There is a Seiko shutter that is the same outer size as a Copal #1, but has larger lens cell mount diameters. (I have one of these with a Fuji 210/5.6; not for sale). Maybe that is what you want, but I don't know if there are also different Seiko #1 that has the same size lens cells as Copal #1.

To get exactly what you want, it might be helpful to say what lens focal length you need it for, and what lens cell mounting thread. Otherwise you may wind up with something that doesn't work.

 

[Ian Grant]

There is a Seiko #1 on eBay with an f5.6 scale. But why specifically a Seiko it would be easier finding a cheaper Copal #1. Reality is often a lens in a #1 shutter may well be cheaper than a shutter on it's own. Don't worry if the retaining ring is missing, they are cheap & post free on eBay

Ian

 

[pdccamerqs]

Thanks Ian and Red - good advice!

I have the lens cells from a Fuji GX680 80mm f/5.6. The lens cells are in great condition - the glass is spotless. I bought the entire lens assembly for a very low price in broken condition to salvage parts to make a LF lens adapter for my GX680. This project is working out fine, but I thought why waste the lens elements if a Seiko #1 shutter could be had for a reasonable price. The GX680 lenses are mounted in Seiko #1 shutters and research I have done on-line regarding re-shuttering GX680 lenses seems to indicate that the lens cell screw threads on the Seiko #1 shutters are not compatible with similar Compur or Copal shutters.

I agree that buying a whole LF lens in shutter can sometimes be less expensive than buying just a shutter alone - so that is fine for me as well.

All the best,

Paul

 

[Ian Grant]

If you have a caliper you can check the mounting screw thread diameters. I have a NIB Copal #1 here's a scan of the specs.

Rimset Compur #1, Ibsor (late versions), Prontor,#1 shutters are all compatible. What that scan doesn't include is the retaining ring is M 39 mm P 0.75. There are Seiko #1 M 46mm P o.75 retaining rings.

If the 80mm cells are not compatible, check with a seller as there may be some variation in Seiko shutter, some #1 were compatible with Compur/Copal.
Your best source might be Mamiya (& Polaroid) Press and C series TLR lenses.

Ian

 

[Rick A]

I have a Fujinon 180/5.6 lens on a Seiko #1 shutter, it definitely DOES NOT fit my Prontor or Copal #1 shutters

 

[reddesert]

For reference here are the measurements for a Seiko LF shutter that looks like a #1, versus the standard Copal. This is from the Seiko on my Fujinon 210/5.6, which may not be the same as the Seiko on the GX lens, so measure to be sure. The columns will get messed up when I post this, but the Fuji-Seiko numbers are first and the Copal are second.

I believe the Seikosha shutters on Mamiya Press and TLR lenses are closer to the standard size and you should not expect them to transfer over.


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 blades ~12.2 mm 10.75 mm


mount thread M46-0.75 M39-0.75


lensboard hole ~48 mm 41.6 mm


iris diam 30 mm 30 mm


body diameter 73 mm 73 mm

 

[pdccamerqs]

Thanks Red!

Your dimensions match the Seiko shutter on the GX680.
Here is what I measured:

front thread	m42x0.75
rear thread	m42x0.75
thickness	22.8mm
front to shutter blades	12.25mm
mount thread	M46x0.75
lens board hole	48mm
iris diameter wide open	30mm
body diameter	73mm

I looked at the Seiko shutters on my Mamiya Press lenses (the later black ones) and on a few Mamiya RB67 lenses (earlier ones) and none of those match. I am not sure about older chrome Mamiya Press or Mamiya C2/3,22/33,220/330 types. I think the kind of Seiko LF shutters that would work would be like this one.

Thanks all!

Paul

 

[B.S.Kumar]

Seiko #0, Seikosha #0 and Copal/Compur #0 shutters are compatible with each other, meaning the lens cells can be mounted freely among these shutters.

Seiko #1 shutters have larger lens cell and flange mounting threads than Copal/Compur #1 shutters. Lens cells from Seiko #1 shutters cannot be mounted in Copal/Compur #1 shutters.

Seiko #1 shutters were mostly used for Fujinon 210mm f/5.6 (single-coated, inside writing) and 250mm f/6.7 lenses. Mamiya RB, Fuji GX680 and Bronica SQ lenses can all be re-mounted in Seiko #1 shutters.

Kumar

 

[pdccamerqs]

Great info, Kumar, thank you!

Paul