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This topic comprises 3 pages: 1 2 3
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Topic: Ilford (film manufacturer) goes bust
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Stephen Furley
Film God
Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002
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posted 08-26-2004 02:35 PM
I did experiment wth Cibachrome A when iit first came out, but II had two problems with it. Firstly, it was very contrasty, and secondly, the fumes were evil when processing in dishes, in a very small, unventilated, darkroom.
A few years ago II had a lab print a couple of 5x4 shots for me, and they look really something.
I was never very impressed with any of the other reversal printing processes, these days I tend to scan the sliide, and have an RA4 print made. I no longer do any colour printing myself.
The idea wasn't new when Cibachrome was introduced, There was a motion pictrue process which was based on the same idea. It was called Gasparcolor, and was used for a while in the '30s. It was printed from separations, rather than colour positives, and I don't know if any features ever used it, but several animated shorts and advertisments did.
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Stephen Furley
Film God
Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002
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posted 08-26-2004 02:36 PM
I did experiment wth Cibachrome A when iit first came out, but II had two problems with it. Firstly, it was very contrasty, and secondly, the fumes were evil when processing in dishes, in a very small, unventilated, darkroom.
A few years ago I had a lab print a couple of 5x4 shots for me, and they look really something.
I was never very impressed with any of the other reversal printing processes, these days I tend to scan the sliide, and have an RA4 print made. I no longer do any colour printing myself.
The idea wasn't new when Cibachrome was introduced, There was a motion pictrue process which was based on the same idea. It was called Gasparcolor, and was used for a while in the '30s. It was printed from separations, rather than colour positives, and I don't know if any features ever used it, but several animated shorts and advertisments did.
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Mark Gulbrandsen
Resident Trollmaster
Posts: 16657
From: Music City
Registered: Jun 99
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posted 08-26-2004 08:25 PM
"Does Ilford work with all the dyes being present and selectivly bleaching them?"
Yes, thats what the sulphuric acid does thats in the bleach step. I believe the dyes used are Azo type dyes. They are basically permanent after processing. All of my older home done Ciba prints that I made over 20 years ago look just like they did when I made them. BTW: Ilfochrome paper is gray in color is you look at a sheet conforming the presence of the three color dyes. If you tear a sheet(hard to do but possible) you can actually see the three color layers at a ripped part of the paper.
I found this stuff on the web....... its a much better description that I can pull off so here it is:
"ILFOCHROME (also known as CIBACHROME) was developed by the Ciba-Geigy Corporation of Switzerland in the 1960s. It is a positive-to-positive color printing process which takes an original positive *transparency and creates an original positive print image while retaining a first generation sharpness without the need for an *internegative. Other processes such as negative printing processes, "Type R" processes offered by Kodak, Fuji and others, are often referred to as chromogenic processes. These processes use color dyes that are in the chemistry. These color dyes then interact with the developer to form a color image on the paper. With the Ilfochrome Classic the dyes are built into the paper and are bleached out selectively in processing. These dyes are called AZO dyes and are known for their vivid color, stability, and longevity.
Ilfochrome Classic prints are renown for their archival qualities, rich colors, and sharpness. This sharpness is due to the fact that the dyes are in the paper, not in the chemistry, and the dyes in the emulsion act as an anti-light scattering layer. Because of this, the projected image does not spread out as it penetrates and exposes the emulsion.
Unlike chromogenic processes, which create greater quantities of toxic dyes, this process is also more environmentally friendly as it does not waste chemistry. The fixer is conventional and processed after use for silver removal while the developer used for the Ilfochrome process is similar to that used in black and white processes. In the bleach step any sulfuric acid used is neutralized with sodium bicarbonate before disposal and contains no toxic substances after it has been treated.
The most common of the two printing surfaces use in Ilfochrome Classic is the glossy. This surface contains no paper but is made entirely of plastic with a polyester backing. This is also the paper that is used in all archival tests. The second type of paper, called Pearl, has more of a matte surface. It is made of a resin-coated paper material, and though it still has the same emulsion and characteristics of the glossy paper, the Pearl is not considered archival. Therefore, archival in this case has nothing to do with fade-resistance as the same emulsions are use by both types of paper. What it means, in extremely rare cases, is a possibility that the emulsion can separate from the backing. With this in mind, most professional photographers will prefer to print using the glossy paper.
It is important to note that this process is different from the Ilfochrome Rapid method. Ilfochrome Rapid is a faster process and has very different printing characteristics. Therefore, when a lab does your developing be sure to specify which process you want. If you're not sure or you are having difficulty finding answers ask what chemistry they use in the processor. P3, P3X, P30, and P30P are the only chemicals that can be used with the Classic material. If you are told its P4 then the lab is using the Rapid material. If you are considering the purchase of a photographic work of art be sure to look carefully at the print and ask the photographer about what processes were used."
Link: http://artisticforum.com/ArtFacts-WhatisIlfochrome.html
Mark
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John Pytlak
Film God
Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000
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posted 08-26-2004 08:31 PM
http://www.lightroom.com/lr_pages/ilfo_info.html
quote:
What is Ilfochrome Classic (and why isn't it called Cibachrome anymore?) Cibachrome (we'll get to the name change in a moment) was developed by the Ciba-Geigy Corporation of Switzerland in the 1960s. It is a color print material for printing directly from color transparency film, without the need of an internegative...
...The dyes used are called AZO dyes and they are known for their exceptional stability and color purity. Ilfochrome Classic prints are known for both their archival qualities and their rich, saturated colors. When you compare them to other prints, they are also noticeably sharper and this is directly due to the dyes being in the paper, not in the chemistry. By incorporating the AZO dyes in the emulsion, they act as an anti-light scattering layer, keeping the projected image from spreading out as it penetrates and exposes the emulsion.
http://www.freelanceperceptions.com/html/htmlcommon/lanceilfochrome.htm
Kodak Kodachrome film likewise does not have dye forming couplers in the film itself. The couplers are contained in three separate processing solutions, making the K-14 process rather complicated, but with the film having a somewhat simpler formulation:
http://www.pbs.org/wgbh/amex/eastman/peopleevents/pande19.html
quote:
The Kodachrome name was revived, and on April 15, 1935, Kodachrome motion picture film went on sale. Shortly after that, Eastman Kodak introduced Kodachrome film for color slides. The process by which this film was developed was -- and still is -- maddeningly complex, but as with everything else at Kodak, the amateur did not have to worry about that, since developing was handled by the company. Vivid color photography for everyday use had become a reality.
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