Develop, then expose

[Alpha]

From COMPLETE BOOK OF SCIENCE , 1958 ed by LITTLE & IVES

EMMERMAN PROCESS. The Emmerinan process, some-times called the Direct
Person Process, is a method of producing masks directly on photographic
prints during processing for the purpose of obtaining good tone
separation. The Emmerman process is an automatic masking method for use
in prolection printing. With this method, a silver mask is formed on
paper by partially exposing a sheet of sensitive paper soaked with
developer, on a glass plate on enlarger easel and allowing it to
develop out fully before completing the exposure and developing the
print in a tray.
The mask formed protects the shadow or dark areas of print so they do
not become blocked up on the second exposure. The method is of
particular value in making prints from negatives of subjects having an
extreme brightness range, or an exposure scale too long for the print
emulsion.
Three requirements are necessary for success with the Emmerman process.
The developer must not fog or stain the wet paper while the mask is
being made. The emulsion should not show reversal tendencies during
the second exposure. It is advisable to use a paper grade one degree
more contrasty than the negative normally requires.

No idea who Emmerman was.

 

[Helen B]

Good find. From old SMPTE papers and Neblette's Photo Materials and Processes (1952) it looks like he may have been a German photo chemist working in the 20's and 30's. Not Norwegian at all.

 

[ann]

reminds me a bit about chemical painting. In this case we "place" the developer on the paper as it is being exposed.