Years ago you could buy a template for exposing paper to the negative that looked like a pie-chart. It had different segments of separate densities that allowed a certain amount of light through them.
You used a known time and aperture and shot the paper. You developed the image on the paper/film and used the properly exposed segment you liked as your basis to give you the "perfect" exposure.
I used the same device to expose X-ray film.
Just remember to turn off the RED safelight when shooting the image. Also keep the RED safelight at least 5 feet away and never brighter than 5 watts.
I maintained several hundred darkrooms in my working carrier that processed x-ray film as well as commercial "normal" films. The general rule of thumb is, go into to your dark room and close the door.Turn off the lights.If you have over head florescent lighting allow the tubes to dim out for at least 60 seconds before you open a film bin or film holder ( after-glow). Let your eyes get used to the dark. Look at all door seals and walls.If your eyes can see any white light light,the film can too.
I simple test you can do is place a piece of x-ray film on your working surface,easel,wet-sink,etc. Place several coins on the film and leave them under your safe light, small light leaks for 60 seconds.Remove the coins and develop the film.If you see circles where the coins sat,your safe light is not safe or you do have a light leak in the room. I could not count the hundreds of times I have found this to be a problem.
9 out of 10 times it was a too close light or someone had placed a bulb greater than 5 watts into the lamp holder. The filter film was damaged by the heat and pin holes were burned into the filter exposing the film.
Sorry for the rant, its just that it is so common a problem the user never thinks about it and gets poor results with their images and cannot figure out why?
Bookmarks