Arc powered magic lanterns or film projectors probably aren't as common
now as they were ninety years ago (Luis Nadeau has previously described
the modified beast the Fresson family is still using). With such a hot
light source you'd probably still have to duplicate your negative so as
not to fry a precious original (why not enlarge it anyway?).
On the other hand it probably is possible to sufficiently increase the
sensitivity of dichromates with a few chemical modifications. Jaromir
Kosar's _Light-sensitive systems: chemistry and application of nonsilver
halide photographic processes_ mentions various additives prescribed and
sometimes patented over a few decades to 1965: from memory some seemed
quite toxic; some probably don't work adequately; and all were beyond my
limited chemical capabilities. I can appreciate that somebody whose done
the research may want to get something back for his/her time and effort;
but there's not alot of money in alternative photography. If it's really
practicable maybe the inventor would be content with everyone's gratitude
(and having the modification named after them?).
Philip Jackson
pjackson@nla.gov.au