Film longevity(a much delayed response)

[P3D John Bradley <JB3D@xxxxxxxxxxxxxx>]

During the February discussion of film longevity Michael Kersenbrock
mentioned "a well known book that addresses these topics", although
he went on to say he hadn't seen it himself.
The book was
The Permanence and Care of Color Photographs:
traditional and digital color prints,color negatives,slides and 
motion pictures
by Henry Wilhelm (with Carol Brower)
Preservation Publishing Co
Grinnell Iowa USA  1993
ISBN 0-911515-00-3 (hardback)
           0-911515-01-1(paperback)

Thanks to Michael's tip I ordered a copy from my local library. It has
taken 
some time to come , as they had to borrow a copy from the British
Library,but arrived this week.

The book is fascinating , and my purpose in writing is to recommend it to
anyone with even a modest interest in the preservation and durability of 
their photographs/slides.  At 744 pages it is a "big read" , but is written
in
 a lively accessible style, and is profusely illustrated in b/w and colour
 ( back to the correct spelling now).

It deals with the technical details of photograhic decay and preservation
in great detail , but also sets out key issues in helpful tables and 
summaries giving reccomended film choices for different situations. It
also tackles the "preservation" issues connected with modern digital
forms of storage.

All the technical detail is interspersed with a fascinating account of the
commercial and social context in which all the scientific work on longevity
took place.  This includes the commercial pressures 
that led Kodak to keep secret what they already
knew about the impermanance of  some of their products, as well as
their attempts to deal with researchers such as the author who published
uncomfortable results.

I have not finished the book yet , but so far I've been particularly
interested
in the recommendations for maximum accumulated projection times for
different slide films to avoid fading. A whole chapter is devoted to
projector
cased fading .   We all know I'm sure of  Fuji's better tolerance of 
projection compared to Kodachrome , but it was helpful to
have this quantified:-

Fujichrome (all brands except Velvia)five and a half hours
Fujichrome Velvia four hours
Ektachrome two and a half hours
Kodachrome one hour

The finding that not only do glass mounts for slides provide no
protection(hardly surprising),but "may somewhat increase rate of
fading" was another interesting conclusion from the data.

A  highly recommended book if you wish to avoid what the
poet Swanson called
"films once commanding B.O. gross
just rotting nitrocellulose"

Kind regards
John Bradley
JB3D@xxxxxxxxxxxxxx


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