spacers for 15 inch (375mm) Caltar

[lenser]

I just acquired a beautiful set of lens clusters for a 14 inch Caltar. I already have a 250mm WF Ektar in an Ilex #5 shutter, the same shutter as needed for the Caltar elements, so I had just planned on swapping the sets of elements as needed since the f stops are the same for both lenses. I had hoped that they would require the same thread diameters as the Ektar, but that's not the case....they need a larger diameter. That leads to the assumption that that I will need spacers, not only for the diameter, but also for the offset distance, but I have not been able to locate any schematics that show the sizes needed for both front and back sets. Can anyone out there in Large Format genius land help with the needed data or better yet, with an actual set of spacers?

I've got a brilliant machinist locally who can create these, but we need the actual measurement data first so we can be sure of getting the precise required distance between the two sets of elements.

Many, many thanks.

Tim

[Jon Shiu]

I have heard that they go right into the Ilex 5 without any adapters, ie 75mm, 75mm. Apparently the shutters for the Kodaks are slightly different.

Jon

[Jason Greenberg Motamedi]

Kodak had their own version of Ilex shutters made, so as you guessed you will have to get someone to provide the measurements and then have them machined. I can't help with the measurements, but is it worth it? The 375mm Caltar is a decent lens, but not a very valuable one.

[lenser]

I had no idea that there were different versions of the shutter.Sounds like the only solution is to either find a version for Caltar lenses, or pass these on to someone who has a shutter that works. Machining spacers would apparently work physically, but not optically as they would have to mount outside of the shutter instead of within it.

thanks for the expertise.

[Brian C. Miller]

c.d.ewen on the forum will have the measurements for both. Earlier this year I sent him a #5 Kodak shutter to have a lens adapted for it.

[Mark Stahlke]

...the f stops are the same for both lenses.

Careful there, the aperture scales for the 250mm won't be accurate for the 14 inch (355mm) due to the different focal lengths.

[c.d.ewen]

c.d.ewen on the forum will have the measurements for both. Earlier this year I sent him a #5 Kodak shutter to have a lens adapted for it.

Brian! You narc, you!

Tim:

Read this article on SKGrimes' site, and note what they say about Ilex shutters made for Kodak. Have your machinist use the dimensions listed on the bottom of that page - they are for the non-Kodak Ilex shutters.

I have an Ilex 5 that used to have 375mm Caltar cells in it; it still has the f/stop scale on it. I'll see if I can get it out and take a picture of it. If you pick up another Ilex, you can use it to make yourself a scale.

Charley

ps: Need a spare set of 375mm Caltar cells?

[lenser]

Thanks for all the very helpful answers.

Brian, I'll contact Mr.Ewan today.

Mark, I had guessed there would be a difference and planned on adapting a temporary aperture scale by testing the exposure levels on the ground glass with my Minolta III and the ground glass probe.

Charley, I would appreciate the photo of the scale. That would be very helpful. The odd thing is that the shutter I have (unlike the one in the Grimes illustration), has no mention of Kodak at all. It just has the Ilex Universal #5 label but is most certainly dedicated to the 250mm cells. The diemnsions I found on their site don't seem to relate to the front to back spacing which is the critical dimension if this can even be made to work.

[c.d.ewen]

I would appreciate the photo of the scale.

Tim:

Yeah, I get it now - "Show Me" I hadn't noticed before.

Attached are some photos of the original scale, with the aperture lever in the max open and closed positions.

Because I swop a couple of different lenses into the Ilex 5, I put a scale marked in millimeters onto the side of the shutter. I've included photos of that, also. When the right side of the aperture lever is on the carat, the aperture is open approximately that many mm. Sorry, I don't kern well on the label machine, so don't treat the measurements as perfect.

Here are the approximate openings for the 375mm Caltar:

f/6.3__51mm
f/8___41
f/11__30
f/16__20
f/22__15
f/32__10
f/45___6

Charley