A photogram is a camera-less image made by placing objects directly onto the surface of photosensitive material and exposing it to light. The process was invented in 1834 by Henry Fox Talbot, when he set a pressed leaf on a piece of sensitised paper, covered it with a sheet of glass, and left it in the sun.
The light source I used was a colour photographic enlarger with either a cyan, yellow or magenta filter. See Lloyd Godman's Photogram Pages.
image copyright Lloyd Goodman
Setting up my materials with a safe light, I added food colourings, water and olive oil in shallow glass dishes, placed the dishes on my photographic paper and exposed them to the light for 1 second. This produce patterns with resemble planets and suns. By using yellow food colour and a yellow filter, I produced blue images (its complimentary colour). By adding blue food colour to this, I produced an image with magenta, and so on.
With my sunstar image, I used a blue glass bottle, and placed a black card sleeve around the bottle to forma tube also covering the lens. This acted as a funnel focusing the light. I then placed a piece of card with tiny holes in the negative carrier and exposed this on my photographic paper for 1 second using a cyan filter. This produced an image with both yellow and magenta plus an interesting texture caused by the card with holes.
Eclipse 1 was made with blue and yellow food colouring, oil and water and a Magenta filter.
Eclipse 2 was just blue food colouring with oil and water and a Magenta filter. The blobs of food colour resemble planets in front of the eclipse - I really like this one.
Blue Eclipse was blue food colouring, oil water and a Yellow filter.
Blue Eclipse 2 was blue and yellow food colouring, oil and water with a Yellow filter.
Blue Sun Spot was yellow food colouring, oil water and a Yellow filter, and finally
black hole was yellow food colouring, oil and water with a Magenta filter which left the green ring.