Restoring a stained 8x10 diacetate copy negative

The negative arrived today. I wanted to provide an update since you were
all so helpful.

Once again, here is a link to image:
http://i20.ebayimg.com/01/i/000/8c/a7/07fc_12.JPG.

It would help to know, though, what kind of stain it is exactly. Can you
describe it--color, intensity, etc.?

The stain is yellow and is on the emulsion side. The result can be found on
the right side of the scan.

I also learned who the seller was of this and many other vintage items -
Mark Vieira. Vieira was once Hurrell's assistant. He has also authored
several books. It all makes sense now. Who else in this world would have
such a great collection of other people's work?

His work can be viewed at http://thestarlightstudio.com/

I will move forward with getting the negative scanned.

Carl Wegerer, III
Mesquite TX

Carl Wegerer wrote:
The negative arrived today. I wanted to provide an update since you were
all so helpful.

Once again, here is a link to image:
http://i20.ebayimg.com/01/i/000/8c/a7/07fc_12.JPG.

It would help to know, though, what kind of stain it is exactly. Can you
describe it--color, intensity, etc.?

The stain is yellow and is on the emulsion side. The result can be found on
the right side of the scan.

I also learned who the seller was of this and many other vintage items -
Mark Vieira. Vieira was once Hurrell's assistant. He has also authored
several books. It all makes sense now. Who else in this world would have
such a great collection of other people's work?

Hurrell's family also has a web-site devoted to his work, although I
don't know if they would be willing to sell negatives, even copy negatives.

http://hurrellestate.com/

Two other ways we do this in our lab:

1: Dupe onto Ektachrome duping stock, which although is a color
emulsion, it makes a satisfactory copy if done well.
2: Drum scan the original, eliminate the stain using Photoshop channels
masking tools to isolate the color, and then make a new negative on B&W
sheet film using a high resolution LVT film recorder. This process is
virtually lossless and can actually yield a better negative than the
original.

john c.
tech photo & imaging
www.technicalphoto.com


----- Original Message -----
From: "Richard Knoppow"
Newsgroups: rec.photo.darkroom,rec.photo.equipment.large-format
Sent: Monday, February 26, 2007 9:44 AM
Subject: Restoring a stained 8x10 diacetate copy negative


On Feb 26, 4:40 am, Toni Nikkanen wrote:
"Richard Knoppow" writes:
You can also
make a duplicate. This will required two steps. Probably the
best currently available film is 100T-Max or Fuji Acros.
When developed in Microdol-X or Perceptol used full strength
these films have excedingly fine grain and very good
resolution. You will have to make a positive from the
negative and a duplicate negative from that.

Could the duplicating process be improved by processing the
positive gained in the first phase into a negative, using
the processes one uses for making positive film out of negative
B/W film? (Going around thinking positives from negatives and
negatives from positives makes my head spin.)

It _is_ possible to make duplicate negatives by reversal. Such
materials were on the market up to a few years ago. Most reversal
processes are intended to make a positive for projection with a gamma
of about 1.0. Presumably, if the original is a low contrast negative
the duplicate would also be low in contrast but I think it would some
fiddling to be sure. Kodak made a reversal kit for T-Max, I don't know
if its still available.
Making a positive from the original and a negative from that is
not too difficult but this also would require some experimentation to
get the exposures and development right. Scanning is probably a lot
simpler. Its possible to make a negative from the scan. Making
negatives is done commonly for alternative printing processes where a
large size negative, suitable for contact printing, is needed from a
smaller negative. The scanning process also allows adjustment of the
characteristic curve of the resultant negative and, of course, allows
the necessary retouching.
I suggested making a duplicate negative because it is one way of
removing stains and some other blemishes without damaging the
original. I would be very reluctant to subject this negative to any
chemical treatment.

--
Richard Knoppow