pinhole negatives without electricity?
A friend of mine who has taught many workshops on pinhole and camera obscura, now contemplates something trickier: teaching in the countryside of South America, in places without electricity. For the prints she'd use the same precoated cyanotype squares she's used in children's classes all along-- they can be exposed by sunlight and developed in water.
The catch is making the negatives. In the US, even if she's not in a lab or regular photographic setup, it's easy to turn a room, a closet, or other space into a "darkroom," and expose & develop black & white photo paper to make a paper negative by pinhole camera.
But "in the field", that is, literally outdoors, not. Friend asked me if I knew of an emulsion "fast" enough to make an image by pinhole camera that could be coated in, say, heavy shade, ie., without a darkroom. That struck me as a contradiction in terms. (Yeah, I thought of Terry K's vaunted "rex" emulsion, but didn't recommend it.)
I figured a pinhole neg wouldn't be feasible by handcoating, but negatives from a digital camera could be printed on a "portable," that is, battery-operated inkjet printer. True, that requires some access to electricity for recharging and more expense for the printer than, say, a shoe box and a piece of tin foil, but odds are she'll have some access to electricity at night, even if not "in the field."
In any event, I promised I'd "ask the list," where there may be better knowledge or experience. Suggestions would be very welcome, also any experience or advice about battery-operated printer for negatives.
(One suggestion I got already was "take spare batteries." Definitely!)
with thanks in advance for info or advice,