jakobj
Hello,
I recently managed to pick up a partially used roll of ‘FL – highly sensitive, standard, white 50m * 100cm’ photoline film, manufactured in the GDR, at a flea market.
I’ve given it a go and, apart from a few instances of fogging on the outer emulsion layers, it’s still in decent condition.
Unfortunately, the prints have turned out a bit low on contrast and dull, probably due to its age.
Does anyone have any ideas on how I can get slightly sharper images out of this material? A richer black with true white?
Thanks in advance,
Jakob j
MirkoBoeddecker
Jacob,
We are currently working on various anti-haze agents.
Once these are available, you can combine them with a high-performance developer.
By extending the exposure time and adding the fogging agent, the occurrence of base fog is suppressed and the curve is adjusted so that a good gradation of grey tones is restored right down to the black.
We are trying to formulate these fogging agents in such a way that they do not alter the tonal range.
Best regards,
Mirko
cfb_de
Hi Jacob,
Use Dokumol, diluted a bit stronger (1+7), during processing at a slightly higher temperature (around 25°C), and add a pinch of benzotriazole (a knife-tip per litre).
This makes old emulsions harder and at the same time removes a slight (!) fog.
That’s how I even get my hopelessly soft, over-stored Varimax up to a fog-free gradient 3. Which is usually enough. It does remain a bit bluish, but it responds wonderfully to uranium toning afterwards and is therefore still usable.
Best regards,
Franz
[Yes, yes, not just as a chemist, bomb-maker, pyrotechnician... even as an amateur photographer, having your own chemicals shelf makes perfect sense at some point. For photographers, I recommend the following minimum stock: potassium iodide, potassium bromide, benzotriazole, potassium hexacyanoferrate (‘red’, to avoid confusion), sodium dithionite, citric acid, soda, formalin solution, isopropanol, ethanol (‘for UV spectroscopy’, which cleans every lens streak-free). Minimum stock. You might also want to add sodium sulphite, metol, hydroquinone, vitamin C and the like, so you can make your own developers. Sodium thiosulphate would also be advisable. Before buying anything, it’s essential to brush up on your chemistry. Much of this stuff is absolutely not suitable for the uninitiated, or even for storage in children’s rooms!]
cfb_de
Hello "me" (because, in the interests of clarity, I’m answering myself),
what’s all that stuff on the shelf for:
["*" and "+" see below]
- Potassium iodide*: Fixer test for silver.
- Potassium bromide*: To prevent fog, for warm-toned developers.
- Benzotriazole*: To combat fog, produces a cooler tone.
- Red blood salt* (potassium hexacyanoferrate(III)): For bleaching agents. An acid (vinegar essence+, citric acid+) is also required.
- Sodium dithionite*+: Silver replenishment from old fixer.
- Citric acid+: Stop bath.
- Soda+: The alkali for everything, film development.
- Formalin solution*: Baryta high-gloss.
- Isopropanol+: Cleaning agent, cheap. Can dissolve coatings. Nobody drinks it.
- Ethanol*: Better cleaning agent, can dissolve coatings. As "methylated spirits*+": Best substitute for "Drysonal".
- Sodium sulphite+: Preservative/buffer substance.
- Metol*/hydroquinone*/Vitamin C+: Developing agents.
- Sodium thiosulphate*+: Fixer, for toning.
Substances marked with "*" are not entirely harmless to health (nothing happens if handled properly; they are also largely found in common photographic/household chemicals), substances marked with "+" are available cheaply in supermarkets or from Raiffeisen in 20kg sacks/canisters.
I have assigned the "*" symbol taking into account the greatest possible anxiety and the highest possible safety standards. I have deliberately ignored any compliance with German hazardous substances legislation and classified them extremely strictly. This should also sufficiently appease hobby laboratory technicians affected by Reich occupational regulations (who demonstrate against "particulate matter" from cars, yet prepare their own selenium toners).
Best regards,
Franz
PhilippReichmuth
Hello Franz,
It does still retain a bluish tinge, but it responds wonderfully to uranium toning afterwards and is therefore still usable.
Do you make your own uranium toners? If I’ve understood
these pages correctly, you’ll probably need uranyl nitrate for that. Is that easy to get hold of, or do you run into problems with radiation safety regulations or the like?
I wasn’t planning on making the stuff myself; as a chemist, I’m a bit of a layman – my experience with chemistry is limited to making simple to moderately complex explosives back in my teenage years :) Uranyl nitrate also seems to be relatively toxic. But if you happen to find someone who works with it, you can always ask them about it :)
Philipp
cfb_de
Hello Philipp,
Yes, I prepare it myself. Depleted uranium compounds are no longer subject to radiation protection regulations, so I was once able to buy 25g of uranium nitrate (probably the last of its kind available over the counter in Europe) without any problems.
However, due to its toxicity (and general panic surrounding uranium), it is no longer readily available (proof of expertise, end-use declaration required).
Best regards,
Franz
