Light striped prints

Another printing fault is light pollution known as fog. This is assuming it hasn't happened in the camera.

The dark line you see running up this picture
 it the result of light
getting to the light sensitive material. Fogging .

●         It Could be where stray light from a darkroom not properly blacked out has found its way to the light sensitive side of the the paper you're using.

●         Your safe light is too close to the enlarger and or the wrong colour.

●         It can also happen if your enlarger leaks light when being used.

●         Badly stored and out of date paper can also be fogged.

The causes of these faults, also point to ways of curing them. This post suggests a way of detecting light induced fog.

Darkroom fog!? Safe light.

No I'm not talking about the weather but about the lighting in your darkroom. Is it safe? Is it the right colour? Is it to close to the enlarger or developing dishes? How do you find out?

There is a simple test, you will need to cut some photographic paper into about 6x6 (150 x150mm) and lay them flat in various places with the lights off around the darkroom with a small object like a coin on the top. Don't forget to mark each piece with the location you have placed it in. Switch on the safe light(s) and leave them for five minutes.

Then develop all the pieces as you would normally, if they all come out blank then there is not a problem. However if you can see the image of the object/coin on any of them you know that the light is too strong in that place and will fog any paper you leave out. You could move the light further away. Now if all the bits of paper show signs of an image it means that the safe light is the wrong colour and will need to be changed or your darkroom is not light tight.