Published: Feb 2020

Darkroom

If you just want to develop roll film (35mm or 120/220 sized medium format), you don't really need a darkroom. So long as you have a completely dark space in which you can load the film into the tank, you can do all the processing in a home laundry or similar facility, providing you ensure there is good ventilation and you clean up thoroughly afterwards.

For loading and developing large-format sheet film, and for wet-process printing, it really helps to have a dedicated darkroom. It doesn't necessarily have to be a converted spare room. I've seen darkrooms built into the corner of a garage and in caravans. Remember to pay attention to ventilation. You want good air exchange, with air flowing from behind you, over the chemistry and then vented outside. This generally involves labyrinths of some kind to allow the air to flow freely while keeping the light out.

My home darkroom, now decommissioned, in glorious cylindrical projection. On the left you can see my colour-coded 4x5 development tanks, home-made enlarger timer built from old-fashioned 4000-series CMOS logic chips, and a Beseler 45 MCRX enlarger. The door has  vents cut into it to allow airflow, and baffles on the back to form a light trap. The box with the clock attached is built over the window, and contains exhaust fans and light-trap baffles. It has a hatch in it so you can reach through to open the window to allow the fans to suck the fumes out.

Looking into the darkroom from the doorway. In this view you can see the hatch on the fan box.

The front of the door has three rectangular holes cut into it, covered by grilles. The rear of the door, shown here, has a light-trap labyrinth attached to it to let the air through.

The fan box with the hatch open to allow access to the window.