Som Berthiot Eidoscope 375mm f4.5 - Coverage?

[Craig Tuffin]

I've recently acquired this lens in terrific condition and was wondering if anyone could tell me if it will cover 8x10. I have heard that coverage doesn't increase as you stop down on these lenses, that the iris/aperture primary affects the soft focus (please correct me if I'm wrong )
It unfortunately didn't come with a flange, and as I'm in Australia it's a little more difficult to send to Grimes etc. It looks to be about a 98mm flange size. Can anyone give me more information or somewhere I might find one to purchase?

Cheers

[carverlux]

I've recently acquired this lens in terrific condition and was wondering if anyone could tell me if it will cover 8x10. I have heard that coverage doesn't increase as you stop down on these lenses, that the iris/aperture primary affects the soft focus (please correct me if I'm wrong )
It unfortunately didn't come with a flange, and as I'm in Australia it's a little more difficult to send to Grimes etc. It looks to be about a 98mm flange size. Can anyone give me more information or somewhere I might find one to purchase?

Cheers

Craig,

Congratulations! The Eidoscope is a fantastic lens. It performs very well under a variety of situations, including both portrait AND landscape - which is actually not true of many soft focus lenses.

Attached is a catalog page showing the f/5 No. 2 covering 18 x 24 at Portrait distances so you are probably tight to OK if that is your question. You are also quite right that coverage will not significantly increase as you stop down, especially with the f/4.5 lens. But there is a little leeway and given the tolerance that these antiques are built to, YMMV.

I am sorry I am no help on the flange but good luck with exploring this lens. I just did some work last week with my f/4.5 No. 1 and was reminded again that I am still not as good as the lens is.

Best,
Carver

[Marko Trebusak]

Congratulations on your eeeeeem new lens!

As for flange, your best bet would be local machine shop with lathe and technician willing to work what you would like. Finding the right flange is probably the best approximation to "needle in the haystack" saying in LF world.

Cheers,
Marko

[Dan Dozer]

Hi Craig,

As the others have said, this is a beautiful lens to work with and, for portraits, it works fine on the 8 x 10 with no vignetting. I haven't tried it at infinity before shooting landscapes but that is something that I want to try. I have the exact same lens and find it a very interesting lens, but one that you are going to have to work with to get used to. As you probably already know, you need to focus it at about F10 and then open up to get the soft look.

If you don't have a flange but want to do it yourself, you might try the method I use if you use wooden lens boards.

Cut a hole in your lens board about the size as the threads on the lens. Use a dremmel tool to widen the hole to about 1/16" or more larger than the threads of the lens. Get from your local craft store a sheet of 1/16" black craft foam (costs about 1$). Cut a strip of foam the thickness of the lens board. Line the hole in the board with double stick scotch tape and put the strip of foam on the tape all around the hole in the board. Then screw the lens into the foam lined hole in the lens board and you're all set.

[Craig Tuffin]

Thanks for all the replies Some great information and tips to get this exciting lens to work. I'll give your technique to get it on a board Dan...cheers. The foam doesn't pull out with a heavier lens? Thankfully the aluminium barrel keeps this one quite light.

[Dan Dozer]

Hi Craig,

The double stick tape keeps the foam in place. I'm not sure what you have available in Australia. The stuff I use is spongy but solid (if that makes any sense). With the foam in place, you want the hole of a size where you have to really work to screw the lens into the foam. If it pushes in somewhat easily without screwing, the hole is too large and you need to put a little more foam in place. I've used this method with my 360 mm Heliar and it's much heavier than the Eidscope is.

Good luck.

Dan

[Louis Pacilla]

never mind

[Jason Greenberg Motamedi]

In a minority report, I find that the no. 2 Eidoscope works perfectly with 6 1/2 x 8 1/2, and only so-so with 8x10. Sure, it illuminates the corners on 8x10 at portrait distances and even infinity, but I find that it sort of "stretches" the corners. Aperture has little effect on the size of the illuminated circle, but it certainly controls softness. f4.5 is soft (but not as soft as other SF lenses), sharpening up by f8 or thereabouts. I use mine around f6.3 for a medium soft effect, and a nice glow in the background.