Copying deteriorated acetate film

    **** Moderator's comments:
    Charles wrote back noting that the original question referred to
    motion picture film but agreed to let me post this item anyway
    as it has wider application than just microfilm

The term "every 20 frames or so" leads me to assume that you are
referring to a microfilm with a base of cellulose acetate.  I have
had to copy items like this, and it can be done, in many cases,
though it is an extremely labor-intensive procedure.

It is a matter of contact printing by hand--taking the damaged
sections of film, carefully piecing them together on a contact
printer, getting intimate emulsion-to-emulsion contact with
duplicating film, and making the exposure.  It is possible to
flatten out some image material which is coming away from the base,
and to match torn sections so that they have continuity and read
easily enough, however you may expect some compromise in sharpness
in some places.

Up until now, I have always done this work on short lengths of film,
preferring to hand-process them in trays--much as one does with
paper prints or enlargements--however for longer lengths, small tank
developing or machine processing are also possible.  Another
possibility is that of hand printing the damaged sections and
splicing this new material into the remainder of the film, which you
have created by machine printing (in a microfilm duplicator).  This
does not sound very practical in the present case, however, since
the incidence of damage is too frequent within the reel.  In any
case, success depends on the severity of damage relative to
planeness of the image material on the base and the care taken in
the procedure, relative to careful matching, tight contact, etc.

This is not the only way of dealing with the problem, however I have
been able to do with considerable success in the past.  It is
largely a question of whether the material is judged to be of a
value which warrants the time and expense involved.

Charles Stewart
Sr. photographic technician
Library Photo Service (Cons.)
University of California

                                  ***
                  Conservation DistList Instance 11:46
               Distributed: Wednesday, November 19, 1997
                       Message Id: cdl-11-46-010
                                  ***