I am a french amateur photographer trying to get into large format. Recently a lenses has picked my attention. It's old Schneider Symmar lens with Compur shutter, a convertible 240mm f/5,6 from 1968-1970. By removing the rear elements it seems to become a 420/12.

I didn't find any information on this forum. Thanks in advance and regards from France

-- Raphael Zeiher (rzeiher@hotmail.com), January 15, 2001

Answers

Hi Raphael. Try here:

Convertible lenses

These lenses are generally only just useable in the converted state.

-- Pete Andrews (p.l.andrews@bham.ac.uk), January 15, 2001.

I think it's a great lens, but the Compur that mine is mounted in doesn't have a press focus feature. To focus I must set it on "T" and then reset the shutter speed before every exposure -- a pain in the tusch. I have no problems with using it as a single element on 4x5.

-- bill mitchell (bmitch@home.com), January 15, 2001.

It helps to use a strong monochromatic filter when using the lens in its converted form. That's because you lose some correction when you remove the front element and using a strong monochromatic filter can reduce the chromatic aberrations. Cheers, DJ.

-- N Dhananjay (ndhanu@umich.edu), January 15, 2001.

Actually many photographers mantain that it is the front that you have to remove, somewhere on old threads in this forum you can read several entries concerning this. It is a notorios thing, Half int the Whole thing so what do you actually espect, unless you have a lens which conbines different elements arranging it into a new lens like the Plasmat all you are going to have is less than half a good lens!

-- Andrea Milano (milandro@multiweb.nl), January 15, 2001.

Thanks all, I appreciate everyones input! I think it will be better to have a combo Fujinon 240/9 and Fujinon 450/12 or Apo Ronar 360/9 on my Linhof Master Technika... I need an extension ring for the 450/12 on my Linhof, but it's the only way with the Master Technika with a "normal lens", non tele.

In France it's very difficult to get informations from the field! Thanks for sharing information.

-- Raphaël Zeiher (rzeiher@hotmail.com), January 16, 2001.