AshigrainColour print · Print film
Du Pont Color Release Positive Type 275
A gelatin-free colour print from three separations.
Du Pont Type 275, a gelatin-free separation release print reconstructed from its 1950 paper: the model derives three separation records from the negative and prints each at a contrast of 2.5. Original vs Ashigrain.
At a glance
- Introduced
- c. 1949
- Process
- Du Pont Type 275 coupling colour development (p-aminodiethylaniline developer; develop, wash, first fix, bleach, second fix)
- Maximum density
- ≈ 4.7
About the film
Du Pont Type 275 was a colour release positive that was never exposed in a camera: it was printed in a register printer from three black-and-white separation negatives, each through a narrow-pass filter.
Engineers of Du Pont's Photo Products Department in Parlin, New Jersey, presented it to the SMPE convention in Hollywood on 11 October 1949, and their paper was printed in November 1950. Colour development by coupling went back to Rudolph Fischer's 1912 patent, but Du Pont replaced gelatin altogether: each layer's binder was a synthetic polymer, an acetal of polyvinyl alcohol, that carried the colour-forming groups itself, so the coupler could not wander. The paper presented this as removing gelatin from a commercial photographic product, and three different binders were needed, one for each subtractive dye. From the top, a blue-sensitive layer formed magenta from the green record, a red-sensitised layer cyan from the red record and a green-sensitive layer yellow from the blue record, with a yellow dye keeping blue light from the lower layers. The layers were designed for a print contrast of 2.5 from separation records of equal contrast, and an antihalation backing was decolourised in development and dissolved off in the washes. Sound could be carried as a magenta dye track or a silver sulphide track, and the paper reported a signal-to-noise ratio slightly better than black-and-white release positive. The Timeline of Historical Film Colors dates DuPont Color Film Type 275 to 1949 to 1953, and the paper names Type 875 as the version on safety base.
Sources for this history
- Synthetic Color-Forming Binders for Photographic Emulsions (Journal of the SMPTE 55, November 1950, pp. 455–476), A. B. Jennings, W. A. Stanton and J. P. Weiss (Du Pont), Internet Archive
- DuPont Color Film Type 275, Timeline of Historical Film Colors, University of Zurich
The look
Du Pont Color Release Positive Type 275 was a colour release print film of about 1949, printed in register from three black-and-white separation negatives rather than from a colour negative. Its three layers used synthetic colour-forming binders in place of gelatin. Ashigrain's version is reconstructed and shown after Ansco Color Negative 843.
Best for
- Late-1940s release-print colour
- Printing from separation negatives
- Comparing separation and negative printing
Compare print films
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film. On this two-colour print (a labelled surrogate) every colour falls between blue-green and red-orange: how deep the blacks go, how the highlights roll off and which lights keep their hue.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film. On this blue-sensitive black-and-white print the colour negative turns grey: how deep the blacks go, how the highlights roll off and how dark the reds and greens print.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film. On this blue-sensitive black-and-white print the colour negative turns grey: how deep the blacks go, how the highlights roll off and how dark the red neon and skin print.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film. On this black-and-white print the colour negative turns grey: how deep the blacks go, how the highlights roll off and how the coloured lights and skin translate to grey.
The same Vision3 500T night frame on each print film. On this blue-sensitive black-and-white print the colour negative turns grey: how deep the blacks go, how the highlights roll off and how the coloured lights and skin translate to grey.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Vision3 500T night frame on each print film. On this two-colour print (a labelled surrogate) every colour falls between a blue and a red dye: how deep the blacks go, how the highlights roll off and which lights keep their hue.
The same Vision3 500T night frame on each print film: how deep the blacks go, how the highlights roll off and how the colour separates.
The same Kodak Vision3 500T night frame, printed on each film.
- Kodak Vision Premier Color Print Film 2393
- Eastman Color SP Print Film 5383
- Eastman Color Print Film 5384
- Fujifilm Eterna-CP 3521XD
- Du Pont Color Release Positive Type 275
- Fujifilm Eterna-CP 3523XD
- Kodak Vision Color Print Film 2383
- Fujifilm Eterna-CP 3513DI
- Eastman EXR Color Print Film 5386
- Eastman Color Print Film 5381 (1972)
- Eastman Color Print Film 5385
- Agfa CP30 Colour Print Film
- SuperCinecolor
- Cinecolor (two-colour)
- Gevacolor Positive 953
- Gevacolor Print 9.85
- Gevacolor Print 986
- Gevacolor Print 982
- Ferraniacolor Positive
- 3M Color Positive 650
- Fujicolor Positive F-CP 3510
- Fujicolor Positive F-CP 3519
- Fujifilm Eterna-CP 3512
- Eastman Color Print 5381 (1950)
- Eastman Fine Grain Release Positive 5302
- Ansco Color Print 848
- Kodak B&W Print Film 2302
- Svema TsP-11
- Svema MZ-3
- ORWO PF 2 Positive Print Film
- Technicolor Dye Transfer (1997 revival)
- Svema TsP-8R
- Shostka Colour Positive (1950s)
- Technicolor Dye Transfer (Process IV)
- Gasparcolor Print
- Trucolor Print (two-colour)
- Kodak Vision Color Teleprint Film 2395
Science & sources
A separation print, reconstructed rather than measured, shown after Ansco Color Negative 843. Its curves and dyes are traced from Du Pont's 1950 SMPTE paper and its spectral sensitivities are named shapes on the paper's spectrogram. The model derives three black-and-white separation records from the negative and prints each at the paper's design contrast of 2.5.
Response curves and the evidence behind the model
Compare manufacturer data with Ashigrain’s response on the same axes. These curves show how the model is calibrated to its sources; they do not establish a match to photographed film.
Characteristic response
Model limits
These images show the film model in use. Spectral response, lighting and viewing conditions include approximations. Halation, bloom, grain size, weave and flicker are not fully measured for each film. The look of real film also depends on development and print timing.
- This is a reconstructed model of Du Pont Type 275. Its layer curves and dyes are traced from the 1950 paper, which prints densities at each dye's wavelength of maximum absorption, not Status A densities; reading them as equivalent neutral densities is an approximation.
- The paper's spectrogram has no sensitivity axis, so the three spectral sensitivities are named shapes on its printed peaks (440, 550 and 710 nm), with assumed edges at 360 and 760 nm.
- The model prints Type 275 from a colour negative: it derives three separation records from the negative and prints each at the paper's design contrast of 2.5. The neutral scale as drawn in the paper has a gradient of about 2.24.
- The traced layer toes part below an equivalent density of about 0.55, so a neutral separation set prints green-cyan highlights.
- The dyes are printed only from about 415 to 680 nm; the model holds the edge values outside that range.
- The layer order, synthetic binders, narrow-pass printing filters, antihalation backing and sound tracks are recorded but not modelled. No MTF or granularity is printed for it.
- The source gives no printer lamp or filter spectra. Their spectral response is approximated.
- The available sources do not measure veiling flare during projection. The model approximates its contribution to lifted blacks on screen, so the result is not a measured projection contrast.
Reciprocity: not modelled. Exposure time has no effect on this film.
Film guide: assumptions and practical choices
This preview combines the print film with the named camera negative. In this comparison, the print has no separate exposure index or measured grain response.
Sources
- Characteristic curves: Jennings, Stanton and Weiss: Synthetic Color-Forming Binders for Photographic Emulsions (J. SMPTE 55, Nov. 1950) in Journal of the Society of Motion Picture Engineers vol. 55 (Jul-Dec 1950), archive.org item journalofsociety55socirich, file journalofsociety55socirich.pdf (Prelinger Library scan, 680 pages), p. 470
- Process: Jennings, Stanton and Weiss: Synthetic Color-Forming Binders for Photographic Emulsions (J. SMPTE 55, Nov. 1950) in Journal of the Society of Motion Picture Engineers vol. 55 (Jul-Dec 1950), archive.org item journalofsociety55socirich, file journalofsociety55socirich.pdf (Prelinger Library scan, 680 pages), p. 470