Archived posting to the Leica Users Group, 1998/08/06

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] color separation via three exposures
From: Harry Haige <haige@compuserve.com>
Date: Thu, 6 Aug 1998 09:49:19 -0400

Hello all,

Calling upon any expertise out there to help me avoid reinventing
the wheel.  I have one of the old Leitz three filter turrets
(14116) and a bunch of the E43 filters and empty E43 rings that
fit it.  Also most of the Kodak gelatin filters in 2" size that
are easily cut for fitting into the E43 frames.  Also a stable
enlarger, the old Focomat IIc.

My project is to develop an easy way to make three successive
exposures through three different color filters onto very fine
grain B/W film.  In theory, the end result will be images that are
perhaps 2-5x higher resolution than conventional color films which
can be combined to make high quality color prints.  Also, the B/W
negatives should keep better over a long period.

I realize that this only works with stationary subjects and that
it may involve some difficulty.  Some potential problem areas that
come to my mind follow and any comments would be much appreciated.

1)	Color separation.  One possible set of red, green, blue
filters is #25, #58, #47B.  Would wider or narrower spectral bands
be better?
2)	Exposure.  I had thought of individual through the lens
readings of a gray card and manually setting shutter speed to that
value when shooting actual subject.  =

3)	Registration.  I see this as the biggest problem.  Any
easy way to align film image to sprocket holes or punch film in
an M camera a la NATRA?  In practice, could I just try to align
the corners of the three successive images at the same points on
the enlarger baseboard at maximum magnification?
4)	Is it at all practical or not worth the bother?  =


Ciao, Harry =