On 2007-10-22, Stephan Goldstein wrote:
On 21 Oct 2007 00:20:32 -0700, murrayatuptowngallery
wrote:

I just read a 10 year old post about using a G-Claron as a 'pseudo-
convertible' by using one cell; performance would probably be better
than 'vintage' convertibles.

I had previously wondered about splitting plasmats but wrote it off as
'sacrilege' on already decent lenses, but seeing the post made me
realize it's been done.

Anyone actually try this with a G-Claron 150 and does it have any
unique qualities, or just 'work'.

Thanks

Murray

I have a saved post from long ago that suggests using a yellow filter
when using it as a convertible (assuming you're shooting B&W). This
was to reduce the chromatic aberration that would otherwise be
corrected by the front cell. The same poster claimed the focal length
was about 300mm for the rear cell only.

Sorry, I've never tried it myself.

Ron Wisner recommends using a strong yellow filter (I imagine any
monochromatic filter would do as well) when using single cells of
his Convertible Plasmat set. This is to solve the problem of uncorrected
lateral color in a single cell. Now I do not use a #15 filter for that,
but I do use B&W filter 58ES MEDIUM YELLOW (022). Note that, when using
a single cell, the focal length tends to be quite long compared with
using a pair together.Of course, this would work only with black and
white film where blue light was not too important.

He presumably makes a corrector lens that has zero power but all the same
distortions so that it corrects a single cell. I ordered one when he first
announced it over 10 years ago, but he is yet to ship me one, so I cannot
say how well it works.

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