The size of a darkroom for photography enthusiasts in their own homes does not have to be fixed. It can be decided according to their own circumstances, such as: study rooms, attics, storage rooms, bathrooms, etc. The size should be more than 3-4 square meters with good ventilation. That's it, just turn on a small exhaust fan for ventilation, and nail some opaque fabric on the doors, windows and gaps. Can't be used in the bedroom or dark room lighting: use a 15W red light to develop black and white photos, and a brown light below 15W to develop color photos. Fixed at a distance of more than 1.5 from the photo paper, you can completely set these conditions yourself.