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Obviously slide film produces positive transparencies; has anything produced positives directly onto some sort of photographic paper or reflective material when developed (other than Polaroid and other instant film types)?

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The Daguerreotype was the first practical photographic method (1835) yielded a positive image on a silver plated copper plate. The image is actually a negative however it appears positive because of the highly polished reflective surface behind it. Actually it was Sir John Herschel in 1839 that realized that any weak negative viewed against a highly polished reflective background appears positive. The outcome was collodion positives called ambrotypes. Next metal plates were painted gloss black and then coated with light sensitive goodies, these were the tintypes. After that, many reversal processes appeared; mainly they found use in photo-booths in the 1940s. Color direct positive prints on paper came next.

  • Can you say something about whether any of these reversal processes are still in use, or whether paper for direct positive prints still exists? – Daniele Procida Sep 5 '18 at 7:09
  • You can Google "direct positive papers" -- The answer is "YES". – Alan Marcus Sep 5 '18 at 13:53
  • Could you expand on the mechanism? As i understand 'negative', light from bright regions of the object will produce a darkening of the corresponding surface on the image. Thus shadows would stay transparent\white hile bright regions would become dark. How does the reflective surface behind work to let the darkened regions appear brighter than the untouched regions? – loonquawl Sep 5 '18 at 16:17
  • @ loonquawl -- How dark or bright is relative. Sunspots are bright glowing gas but when viewed against the super glow of the sun appear black. A film illuminated from the rear is seen as a negative. Placing this negative on a polished jet black surface causes it to appears as a positive image (try one of your negatives as an experiment; the film appears positive because of the relative differences in the black of the film and the black of a polished surface. The plate was coated with “Japan Black” a lacquer with high sheen associated with furniture made in Japan. – Alan Marcus Sep 5 '18 at 16:42
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All photo papers, which are (or were) produced to make prints from positive film, can also be exposed directly in a camera and developed directly into a paper positive.

The last available colour positive paper was the Ilfochrome product series from Ilford. Production was discontinued in 2011.

There is still quite a few manufacturers of B&W papers (search for 'direct positive paper') for this purpose, some of which have emerged over the last few years during the retro analog wave. In theory, you could even process any regular 'negative' photo paper in a reversal process and obtain a direct positive print of some sorts, just by modifying the development process.

This is usually done in large format cameras, since 135 and even medium format cameras would produce rather small prints.

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