"Roman J. Rohleder" wrote in message
...
"Richard Knoppow" schrieb:
"Peter Irwin" wrote in message
The film base is very clear, not grey.
If you are referring to 35mm B&W film being on a clear
base it may be that Lucky is coating an anti-halation
coating under the emulsion.
They are not. And itīs the main flaw I found with these
films.
The location of the coating makes it
function as an anti-light-piping coating as well
eliminating
the need for pigmenting the support.
A friend of mine demonstrated that you could read a
newspaper through
the undeveloped film
Worse is the photographic result - the lack of a
anti-halation coating
(AHU) contributes to halos and an overall unsharp
appearance of the
negativ under certain lighting conditions - like with a
glaring piece
of chrome or metal or the sun within the frame.
Kodak pulled out of the Joint venture with Lucky some time
ago.
Gruss,
Roman
Fascinating, antideluvian film. I am not sure of the
date anti-halation coatings were applied to roll film but
they certainly date back to glass plates. In fact threre are
instructions for making your own coating for plates in many
ancient phtography books. Halation was much worse for plates
than film but its amazing that anyone would make film now
without the coating. Also, the back coating is also used for
countering the curling tendency of the emulsion the
anti-halation dye is usually included in this coating. If
there is no back coating at all I suspect the film will curl
very badly.
FWIW normal emulsion is nearly transparent, this is why
special motion picture effects could be made by bipacking
(running two films through the camera emulsion to emulsion
and exposing through the back of one of them).
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Richard Knoppow
Los Angeles, CA, USA