Archived posting to the Leica Users Group, 1999/03/15

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Subject: [Leica] Re: Scanning and copying old polaroid photos
From: "Michael D. Turner" <mike@lcl-imaging.com>
Date: Mon, 15 Mar 1999 19:33:52 -0800

At 11:20 AM 3/15/1999 -0000, Doug Richardson wrote...
>Realising that the colours on many old polaroid snapshots which I took
>in the early 1980s are starting to fade, I've decided to copy the
>images I want to keep.
>
>My first choice was to scan them using my HP Photosmart scanner. In
>most cases this has worked well, but is not so good at handling a
>common fault I'm seeing on these old polaroids - the reds have faded,
>giving much of the photo a blue tinge, while the whites have a yellow
>cast.

The layers fade at different rates. Surprisingly, often there is enough
information left to recover a pretty decent image. This is especially true
of transparencies, but often you can get amazing results from these old
polaroids. I've had amazing results from images that appeared to the eye to
be monochrome red. Take your favorite image processing software, be it
Photoshop, GIMP, or any others that provide the capability to modify
curves. You will find that the faded layers have low contrast. Play with
the curves awhile. You will eventually produce a reasonable image.

>Unfortunately, the HP scanner seems to exaggerate these faults, making
>the yellow cast even yellower. If it try reducing the yellow level,
>the blue is boosted, making the blue tinge even worse. Recalibrating
>the scanner doesn't help.

Right. Do a "straight" scan--produce an image that doesn't clip high or low
levels and looks more or less like the original. Don't try to bias it too
much. Correct the curves later. This is important. The problem with old
"faded" originals is differential fading of the dyes, producing color
"crossover". Tweaking the individual curves is the way to correct this.

>Next I decided to use my Leicaflex to copy the images onto slide film.
>I set up a table outdoors, fitted an elpro to my 50mm Summicron-R, put
>the camera on a table tripod, and mounted the target photo vertically.
>Alas, the glossy finish of the polaroid is a fine catcher of unwanted
>reflections! Can anyone will experience of copying work suggest what I
>can do to eliminate these reflections?

Set up lamps aimed about 45 degrees to the surface of the original. Usually
this is sufficient if the target is held flat. Polarizing filters on the
light sources help, but if the original is highly reflective and has
texture, like a coin or a heavily textured oil painting which has been
lacquered, you may need to use a polarizer on the lens as well (cross
polarization). This will result in much longer exposures, of course.


Mike

"Sing whatever is well made..."
- -W. B. Yeats