Pseudo solarization

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Pseudo-solarization on a black and white negative
  • Comparison of pseudo-solarizations

  • original

  • Real pseudo-solarization through intermediate exposure with 1000 W.

  • Simulation with Photoshop (stylization filter solarization)

  • Gradation curve bent to U

Pseudo-solarization , also known as the Sabattier effect, is a phenomenon in the photographic darkroom when the film ( negative ) or the photo paper ( positive ) is diffusely post-exposed during processing and then developed. Often, the term solarisation is reduced by the solarization and the technique of making it means solarise . However, the real solarization effect that occurs in the camera with extreme overexposures is not related to pseudosolarization.  

The pseudosolarization, like many photo effects, arose from an error. High image contrasts and clearly defined details favor the creation of appealing effects. Only pictures that inherently have good contrast and clear lines as well as large, clear shapes are suitable for the process.

From the 1960s, pseudo-solarization was a popular stylistic device. From publications from the 19th century it is clear that this phenomenon was "discovered" by many photographers as it often occurred when the light was accidentally turned on. In 1931 the famous Dadaist Man Ray perfected this technique for alienation. The effect was "discovered" by his colleague and lover Lee Miller when she switched on the light because of a mouse or rat that ran over her foot while working in the darkroom.

In early 1860, the pseudosolarization was introduced by De la Blanchère L.M. Rutherfurd and CA Seely described separately and in successive issues of the American Journal of Photography and Associated Art and Science. In the same year, Prince Schouwaloff published a report on the effect in the French magazine Cosmos. The method for obtaining direct positives, published by the French scientist Armand Sabatier on October 26, 1860, had nothing to do with the Sabattier effect, according to the description. At first he did not describe in any way that the collodion layer was exposed after the development. In this publication A. Sabatier probably mentions Prince Schouwaloff and ALPoitevin . Since the printing error in this publication, the name of the author and the effect erroneously named after him have been written with a double t in the specialist literature. It was not until 1862 that A. Sabatier reported again, and here correctly, about the effect named after him. But he does not find an explanation for the phenomenon.

In the digital photography solarisation is not due to the system possible, but can in response to the post-processing images are simulated. To do this, it is necessary to bend the gradation curve from the diagonal into a U-shape. Modern image processing programs allow not only the alienation of the overall brightness, but also the separate processing of individual color components ( RGB or CMYK ).

A picture effect similar to the pseudo-solarization could be achieved with the Agfacontour Professional Film and Developer, which is no longer available .

Explanatory models

In contrast to many photographic effects which have been largely clarified, views on the mechanism of the Sabattier effect are still very divided.

However, there is agreement on the following points:

  • The fact that the Sabattier effect is based on solarization can be rejected
  • The view that interprets the sabotage effect as a mere copying effect of the silver formed during the first development onto the underlying layers is insufficient to clarify the effect.
  • Oxidation products that arise on the first developed grains during the first development cannot be the reason for desensitizing the unexposed grains.
  • The resulting to the erstentwickelten grains bromides may not be sufficient reason for desensitization of not erstbelichteten grains.
  • It was hard to imagine that the silver produced during the first development would have a desensitizing influence on the first developed grains. This point should be explained in more detail.
  • Several authors have assumed that the formation of a latent internal image during the first exposure, which can compete with the second exposure, with the surface nuclei activated during development can partially explain the Sabatation effect.
  • Although the development speed of the second-exposed latent image is greater than that of the first exposure with commercially available films and photo paper, this cannot be the decisive reason for the sabatoid effect.

literature

  • Katja Wedhorn: Light and Shadow: New Design Methods in Photography from 1920 to 1960, Tectum-Verlag 2012, ISBN 978-3828829435
  • John Beardsworth: Digital photography / black and white: Step by step to a great picture !, Markt + Technik Verlag 2006, ISBN 978-3827240590
  • Werner Wurst: Photo book for everyone, VEB Fotokinoverlag Leipzig, 16th edition 1989, ISBN 978-3731100768
  • Solf, Kurt Dieter (February 1973). "Photography; Basics, Technology, Practice". Frankfurt am Main: Fischer Taschenbuch Verlag GmbH. Pages 26-27; 112; 362, ISBN 3-436-01453-2
  • Agfacontour Professional in Photography, Agfa-Gevaert AG Publication no. 151
  • Agfacontour Professional in Science and Technology, C. Sauer, Agfa-Gevaert AG Publication no. 152

Individual evidence

  1. ↑ Ilford: The Sabatier Effect ( Memento from December 28, 2016 in the Internet Archive )
  2. ^ R. Rössing: Laboratory technology . In: Gerhard Teicher (Ed.): Handbook of Photo Technology , 6th edition, VEB Fotokinoverlag, Leipzig 1974, p. 365.
  3. ↑ Chronicle of the German Association for Photography ( Memento of the original from March 20, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , P. 43. @1@ 2Template: Webachiv / IABot / www.dvf-fotografie.de
  4. ↑ ArtFundUK: Man Ray Portraits: Lee Miller's house. In: YouTube. Retrieved April 28, 2019 .
  5. ^ Josef Maria Eder: History of Photography , 1931, p. 367 (English).
  6. ^ American Journal of Photography and the Allied Arts and Science. New Series, New York II (1860), p. 251.
  7. ^ A b c Franz Tomamichel: The photographic sensitivity: 8.5.3. Sabattier effect and interior image reversal . In: Hellmut Frieser, Günter Haase, Eberhard Klein (eds.): The fundamentals of photographic processes with silver halides , Volume 3. Akademischer Verlagsgesellschaft, Frankfurt am Main 1968, pp. 1200-1206.
  8. ^ Bulletin de la Société française de photographie 1860 ( French ) Hathi Trust Digital Library. 1860 .: "S. 306 "
  9. ^ Bulletin de la Société française de photographie 1860 ( French ) Hathi Trust Digital Library. 1860 .: "S. 283, 312 "
  10. ↑ solarization . In: filmscanner.info .

Web links

Commons : Solarization  - Collection of Images