Re: [Gimp-user] how to darken bright areas

[Gene Heskett <gheskett shentel net>]

On Wednesday 04 January 2017 14:57:07 paulhurm wrote:

> I have several hundred World War One era photographs I am working with
> that my grandfather took during his service with the Army Medical
> Corps. I have no negatives so I am working with nearly 100 year old
> B&W prints. I have scanned all of these but my scans have problems,
> one major is discussed here with the hope of getting some suggestions.
>
> Many of these prints have undergone “silver creep” where the silver
> particles have migrated through the emulsion. Of course, these places
> have lost at least some of the detail that was there. When looking at
> the prints, these areas appear dark but if held at the right angle
> light will reflect off of them and they appear bright. When scanned
> these areas mostly appear white and are annoying to look and detract
> the eye away from what detail remains.
I don't know as I would call it silver creep. What it is chemically, it 
that the developer blacked silver, because of inadequate washing, has 
reverted to the silver.

I haven't personally seen enough of this to consider the obvious 
solution, which would be to develop it again, with a modern developer, 
Dektol if you can find it, perhaps even D-23 which ypu have to make 
yourself, then a weak acetic acid stop bath for perhaps a minute to 
neutralize the calcium carbonate accelerator in the developer, then 
refix to get rid of any residual silver, 3 or 5 minutes, then wash in 
running tap water for half an hour or more to remove the fixer, all at 
temps of 68 degrees or so. 75 works faster if you can muster up the warm 
water fast enough.  Then let air dry for at least an hour. I would not 
use a heated dryer for that because it will take on the gloss from its 
hard chromed surface. That will interfere with the scanning.

Yeah, I'm an old fart of 82 now, but I helped in the darkroom at my local 
weekly fishwrap since about 1947, and had my owm chemical darkroom, B&W 
and Color printing, for nearly 35 years starting in the late '60's. So I 
know a wee bit about this.  And while I have never done this, I'd sure 
take one you could waste and see if this proceedure would help mitigate 
the effects of the aging. Locating the chemistry supply in 2017 will 
take a determined search.

> My goal for this post is to ask for ideas on how to darken these light
> areas so they are less distractive. I know there is no hope of
> recovering detail but if these light areas could be darkened I think
> it would greatly improve the view.
>
> The example I hope to attach shows the problem quite well. Around the
> top and right side in particular you should see the problem. When the
> photo is zoomed in on these areas you can actually see what almost
> look like bubbles or clumps of silver.
>
> Here is my current thinking as to one approach to darken these areas.
> A year or so ago I achieved partial success but my notes were one of
> the things that I could not recover after a hard disk crash. Also, my
> memory is shot so I am starting from scratch.
>
> I am asking for help on what steps to take to achieve the following
> again.
>
> 1 – At one point I was able to get most of the bright spots isolated
> and on a separate layer. I had just the spots isolated but can’t
> recall how. I think I might have been messing with luminosity and I
> think had used an add-in but no clue now.
>
> 2 – My plan was to then turn the separated spots dark instead of
> light. I was then going to work with layers, put the spot layer
> underneath and adjust transparency of the upper layer to try to blend
> them together. Is this a reasonable idea?
>
> I have a lot of learning to do so as much detail as possible on
> suggested processes will be appreciated. I will also have to learn how
> to handle transparency layers for step 2 but I think I can figure that
> out without too much trouble.
>
> Again, any thoughts about this process overall will be greatly
> appreciated. Will my thoughts work? Is there a much better way? Any
> suggestions on add-ins to try, etc.
>
> You can get a little better feel for the overall project and see some
> additional photographs at any of the below sites.
>
> Thank you very much for any help!!!
>
> Paul Hurm
> paulhurm gmail com
>
> http://typicalfrenchkiddies.tumblr.com/
>
> https://www.facebook.com/TypicalFrenchKiddies
>
> http://www.typicalfrenchkiddies.com/
> No photos on this site but the Introduction may be of interest.
>
>
> Attachments:
> *
> http://www.gimpusers.com/system/attachments/431/original/p48_TEST_GRAY
> .tif


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>