Cell spacing for 12" Commercial Ektar

[Charles D. Ewen]

I recently picked up a set of cells for an f/6.3 12" Kodak Commercial Ektar, sans shutter. I'd like to mount them into a Copal 3. Does anyone know the proper spacing for the cells?

[Mike Gudzinowicz]

The 12" f/6.3 Commercial Ektar usually was mounted in a #4 Ilex shutter. You can find

the shutter specs at http://www.skgrimes.com/ilex/index.htm, and use those to

determine spacing.

Specs for the Copal shutters may be found at http://www.skgrimes.com/products/index.htm.

I'd suggest that you acquire an Ilex shutter after measuring the cells thread pitch and diameter.

[Charles D. Ewen]

Mike:

Thanks for the suggestion, but I do have an Ilex #4 already. The Ektar cells have a different thread than the Ilex, thus I'd still need to know the cell spacing to mount them.

[Mike Gudzinowicz]

Well, so much for the simple approach.

Perhaps someone (Richard?) can post the lens length (put it on a flat surface,

place a sheet of glass over the lens, and measure the distance between surfaces

- you don't need to take it off the board). With that information, and the

distances the front and rear outside groups are recessed in the cell, one should

be able to get the front to rear (glass) length of the combined cells. Then you

could transfer those numbers to your cells even though the cell design is different.

That should get you close. Then I'd check the lens for obvious abberations using

a window glass replacement for the GG, 20 to 40 x microscope (Radio Shack may

have them) and a distant light filament on which to focus. Most abberations are

very well corrected. Try to minimize spherical abberation if it's apparent.

[Russell Autry]

The Kodak Ilex #4 is different than a regular Ilex #4.

[Rico Obusan]

64mm from cell-to-cell, measured from outside edge of front lens cell to outside edge of rear lens cell, according to my trusty caliper. That's when the cells are mounted on an Ilex No. 4 Acme Synchro. Hope this helps.

[Charles D. Ewen]

Rico:

That sure does help - it's exactly what I was hoping someone would be able to do. Speaking of exactitude, did your caliper really read exactly 64.00mm? Thanks.