Thursday, 17 April 2014

Recent three colour process images

Three colour process, separation negatives shot on Ilford Delta 100 with Zodel Baldalux,
colour RGB image composited in Photoshop CS2
In my post last year, 'An Experiment with Three Colour Photography', I described the technique of using three black and white photographs to produce a colour image. For that experiment I used large format film, which meant the taking of each separate shot was inherently slowed down by the process of shooting sheet film. I also had problems when scanning the negatives to create the colour image, as I had to scan each in two halves, leaving problems with both alignment and balancing the colours in the three RGB channels. I subsequently took the tri-colour filter set with me to St Petersburg last September, but only used them for one medium format shot. By necessity this was hand held, and not much quicker than shooting large format, with the problem of holding the camera and the gelatin filters in front of the lens and then pressing the shutter button with two hands (while a stiff breeze threatened to blow the filters into the Neva river). Despite the results needing a good deal of cropping as each shot was not very well aligned through being hand-held, the very distinctive qualities of the three colour technique made me wish I had used it for a few more shots on this journey.

Hand held three colour process, separation negatives shot on HP5 Plus
with Zodel Baldalux, colour RGB image composited in Photoshop CS2
For the above image, a tripod would have ensured a better alignment of each colour. Using roll film rather than large format means that each shot can be taken with quicker succession, although I was still using a manual camera which required cocking the shutter and advancing the film using the red window between each shot. Anything moving in front of the camera shows the time taken between each frame, such as the figures and waves in the shot above, and the clouds. Recent good weather has provided the opportunity to take some more three-colour images. I had hoped for some cloud-free days, as these are the one aspect of the landscape shots which highlight the brief time discrepancy between each shot, but entirely cloudless days are rare. The image at the top of this post was the best of the recent shots; the photograph immediately below shows some problems with shooting into the sun with the filters held in front of the lens causing reflections. The tri-colour filters I have been using are unmounted squares of gelatin, which have the tendancy to pick up fingerprints very easily, and are difficult to clean and this particularly shows up when the sun hits the filter surfaces, and a slight soft-focus effect results.

Three colour process, separation negatives shot on Ilford Delta 100
with Zodel Baldalux, colour RGB image composited in Photoshop CS2
Three colour process, separation negatives shot on Ilford Delta 100
with Agfa Record I, colour RGB image composited in Photoshop CS2
Three colour process, separation negatives shot on Ilford Delta 100
with Agfa Record I, colour RGB image composited in Photoshop CS2
As the 6x9 format gives eight images on a roll of 120 film, this meant that I could shoot two sets of three colour separations, with two frames left on the film. On some of the films I used these frames to shoot second versions of some colours, but I also tried a two colour separation, shooting just through the red and green filters. When making the RGB composite I used the green filtered negative in both Green and Blue channels, essentially giving a red/cyan colour image. This effect was intended to mimic the two colour bipack systems used in the early part of the twentieth century for colour motion pictures (see the Wikipedia article on Bipack Colour).

Two colour process, separation negatives shot on Ilford Delta 100
with Zodel Baldalux, colour RGB image composited in Photoshop CS2

2 comments:

  1. Nice experiments with Trichromy. I've done experiments with this myself and enjoyed it. There's something about the Harris shutter that doesn't appeal to me so I have a tendency to shy away from scenes with moving components. Here are some of mine on flickr:

    https://secure.flickr.com/search/?w=9093035@N06&q=trichromy

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    1. Thanks for your comment and for the link.

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