Originally posted by longhaircowboy
Those white blotches make me think Fingerprint.
Is it possible they are thumb or other prints imbedded in the print?
The Mcminnville photos are still my best evidence.
They are indeed finger/thumb prints. The question now is how they got there. Were they on the print originally, or did they "develop" over time?
Maybe with this new hi-res version we can get a better idea.
A lot depends on when in the process the print was made and whether it is just normal human sweat and oils, or if the person had some photographic
chemical on his/her hands.
A dry fingerprint left on wet film or wet fingerprint on dry film can leave ridges in the emulsion of the negative which act as little lenses and show
on the print as fairly sharp, fine dark and/or light lines, especially if a condenser light source is used for printing.
Emulsion on print paper is usually hardened enough to resist physical damage from wet fingers, but a person processing film and prints by hand usually
has some sodium thiosulfate (fixer) soaked into the skin which can transfer onto the finished prints. That may later disolve the silver in the image
leaving a blotchy fingerprint, brown and yellowish at first, graduating to white over time. That type of change is progressive, because sodium
thiosulfate is stable and will continue to slowly diffuse through the photo emulsion forever.
The same can happen with just the acids and oils and salt on your fingers if they happen to get transferred to a print (or negative) which was not
completly "fixed" to begin with, or which was not washed properly during processing. You've undoubtedly seen old photos which are faded out almost
completely. Same principle, the finger sweat aggravating and accelerating the process.
Either way, it takes some time, and looks a bit like a coffee stain, lighter in the middle, with brown/yellow edges.
Alternately, the lab tech could transfer fixer onto either the film or the paper before processing; that would leave a blotchy but even-toned,
sharp-edged fingerprint, showing as black on the print if it happened during film processing, white if it was during print processing. Think black or
white ink.
There's one other way it can happen, and it should be of some concern here: potassium ferrocyanide was widely used in hand-processing b/w prints back
in the day, and will also bleach a photograph and so show fingerprints if accidently transferred (despite the ominous name, it's relatively
non-poisonous). In fact, photographers used to refer to potasium ferrocyanide as just "bleach". Bleach was a major retouching tool before
electronics took over. A quick bath in a dilute bleach solution will selectively brighten highlights without flattening the shadows. A bit of bleach
rubbed onto a dark, flat area will pop up the contrast quite nicely. At an extreme, it can be used to remove zits, lighten blemishes, remove
unsightly branches growing out of your subject's head...and hide inconvenient wires and strings. I wish we had real color scans of these pictures:
fixer problems show yellow traces, as I mentioned; one characteristic of bleach is that the effect is color-neutral, with no yellowing.
ThePieMaN noticed a lightened ring around the object in one photograph. It could be the result of dodging, but could also be an artifact of a bleach
job. I haven't looked at it closely yet, but I have a good idea what to look for.
Dodging will generally look like a little cloud, fading out to diffuse edges, and the dodged area will have lower contrast than the area around it.
Think airbrushing with white paint.
Bleaching will usually have sharper edges, and the bleached area will show higher contrast than the surrounding area; the area inside will seem like a
flat-bottomed, round sided bowl (that' the only way I know to describe it). It's like using a wet eraser, if you can picture that.
But, to answer your original question, no, all these ways of screwing-up your photograph will not usually leave a physical impression on the final
picture (Kodachrome and some other esoteric processes are another matter) although bleaching using a cotton swab or wad of tissue can leave very fine
scratches on the surface, detectable with a strong magnifier.
(Can you tell I spent too much of my youth in photo labs?)