When I was told I couldn't’t use my schools darkroom to teach my B&W class due to the pandemic I researched other hands-on methods of image making that I could have my students do from home. I first asked if I could send cyanotype chemical kits and film developer to my class but this was rejected for safety concerns. I settled on three processes that are interconnected through the use of old photo paper. Usually photo paper must be handled under red or orange light to that the silver particles don’t change or expose except to the imaging light from the negative to make the print. People have noted that scraps of paper in the trash turn pastel shades and muted grey when brought out into the light. This phenomenon is what ties these three processes together.
Tarja Trygg gives an interesting description of the process in this document:
http://www.eso.org/sci/publications/messenger/archive/no.141-sep10/messenger-no141-43-45.pdf
The colours in black and white photo graphic paper exposed to light come from finely divided metallic silver growing on the silver halide grains. The latent image, which is typically ~ 10 silver atoms per billion-atom grain is invisible, but on continued exposure the latent image clumps grow so that the first visible signs of a printout image are yellowish, darkening to sepia then a maroonish-brown as the particle size increases. Eventually the maximum exposure produces a slate grey shade. Reversing an image with this natural range of variations will produce interesting colours, which are of course unrelated to the real colour of the scene. However, lightly exposed parts will be bluish and shades of green/cyan will likely appear in the midtones, both of which will lend the positive images a natural look.
Lumen Prints are usually a contact photograph process where objects are laid onto old photo paper and exposed in the sun for a few hours. Anything can be used to block light to make an image. Some practitioners are using negatives to make muted positive images. Acid and alkaline can be added to natural objects which causes interesting reactions while the paper is exposing. There are two camps to the Lumen Print process. One group fixes the image to make it permanent one of a kind image. Others use the paper unfixed but scanned and print the results from a digital file.
In Camera Lumens are sometimes referred to as Lumenbox. The B&W paper can be exposed in a camera for an extended period of time, long enough for the silver to change in the paper to produce the image. Artist Joterman Otero from Spain is credited for naming this process Lumenbox. He makes a simple camera box that uses a meniscus lens that he sells, https://www.instagram.com/joterman/
Tarja Trygg developed a technique of using a simple pinhole camera pointed towards the path of the sun to recorded a solargraphy over a long period of time. Photographers using this method place their cameras outside for up to 6 months. The B&W paper is slow to react but it will eventually record the suns rays and some of the cameras surroundings on the paper.
In these last two processes the artists use the paper as a recording media and scan them to capture the full tones and colors of the light sensitive media. The recorded image is then inverted into a positive and color balance controls applied to bring out the tones of the image. I will discuss each of these processes with tests and images I have been producing in my research.