Making developer from (totally) raw ingredients
Imagine you're on a deserted island somewhere on planet earth.
You have no access to off-the-shelf photographic chemicals (nor to any industrially produced chemicals at all), including no access to your local drug store, diy store, supermarket or similar.
You *do* have some basic laboratory equipment, and can assume that any naturally occurring plants, animals or minerals that can be found anywhere on earth are also represented on your island.
You have an exposed role or two of generic b&w negative film and a small cave to use as a darkroom. How might you go about developing the film?
Any ideas anyone?
A trawl through Wikipedia suggests we might be able to obtain Catechol (a chemical commonly used for developing films) from fresh tea leaves. Apparently 25% of the dry weight of tea leaves is Catachin. We might then be able to heat the Catechol to make Pyrocatechol. But we're not chemists, so maybe this is all wrong.
Alternatives might include getting the Pyrocatechin direct from horse or human urine, or Pyrogallol (an alternative basic ingredient in photographic developer) by heating Gallic Acid derived from Gall Nuts, Sumac, Witch Hazel or other sources. But this process looks like it might require Sulfuric Acid and involve hydrolysis, which is where it all get's messy.
We'd then need an alkaline agent to mix with the Pyrocatechol to make the developer. Sodium Carbonate is often used, and Wikipedia suggests something like this might be obtained by burning dried seaweed, or from Borax, which would need to be mined. Either option sounds like it might be doable, at least in theory.
If we wanted to get snazzy we might be able to add some Sodium Sulphite (which helps the developer keep longer by delaying oxidation) made from the mineral Mirabilite, if we could find any on our island. And just possibly we might be able to make some Potassium Bromide (which helps suppress fogging on the film) through a reaction between iron ore and Bromine, although making the Bromine would be a whole project in itself so that might be an unreasonable goal.
For fixing we understand that plain seawater will provide a fix, given long enough, otherwise we'd need to explore making Sodium Theosulfate by (wikipedia again) heating Sodium Sulfite and Sulfur in water - the Sodium Sulfite derived (again, as above) from the Mirabilite and the Sulfur collected from the local hot spring. Umm, or something like that.
Do any *real* scientists out there have any better ideas? We'd really appreciate some input from somebody who actually knows about this sort of thing. All of the above is almost pure guesswork.
Many thanks for any suggestions.
Do a quick search for coffee based developers.
you can print on leaves. Or make a paper sensitizer based upon flower/leaf pigments.
Seawater makes a fine hypo clearing agent (used by US Navy in WW2 and since...why waste fresh water until final rinse? the basis for the product "permawash")
You may be on an island with a volcanic vent (sulfer based compounds)
I guess you are presuming that a crate full of film washes up regularly?
I've used mint and rosemary from the garden...was a weak dev, but I got an image
where would you get the alkali?....wood ashes?
Vitamin C can also be used as a developer. I did a quick google search and came up with this recipe:
8 oz of water
8 vitamin C tablets (1000mg each)
5 teaspoons of washing soda
Develop for 30 minutes, agitating every 30 seconds.
If you had citrus fruit on your island, and you could extract the vitamin C. However, the washing soda is needed as an activator. So, don't know about where one would run across that naturally.
An interesting article called Coffee, Tea or Vitamin C, Kitchen Chemistry in the Darkroom can be found here.
The expression "taking the piss" comes to mind.
Originally Posted by DarkroomExperimente
I'm not being rude, the expression comes from the old practice of taking the urine from the gents urinals in London by boat in wooden barrels to the North East coast of England, where it was hauled up a cliff face to a chemical works to extract the ammonia.
Urea breaks down to Ammonia, so that's one source of alkali
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Lets not forget that many islands have large deposits of Guano. Often mined on south pacific islands for fertilizer. High in phosphates, etc.
See Banaba Island, for an example of what's left after the aged Guano is removed.
i don't think you folks have found anything to fix the images yet ...
Originally Posted by jnanian
Doesn't work. Has been proved a few times and is what led William Fox Talbot(i think?) to go to Herschel about his problem and he suggested sodium thiosulphate (hypo)
Originally Posted by tim_bessell
If you had a store and too much money to burn, bog standard fish tank dechlorinater is sodium thiosulphate (though not the Tetra branded stuff apparently). I found at Wilkinson's(UK chain of cheapstuff stores) they have small vials of this in the pet fish section but it works out to be quite pricey compared to buying normal raw chemicals (£2 for about 25g maybe?).
How interesting that this thread came up, as I was just thinking of the scene in a movie I once saw - "The Killing Fields", I think -- where a man's survival in a prison camp depends on him being able to make a photo that can be placed in a fake or altered document. My memory is that they failed, as they couldn't properly fix the image.