I have made the following videos to show how simple it is to develop films using Rondinax daylight-loading tanks and their clones. These videos are are all on YouTube.

Rondinax 60 for 120 film (also applies to Kent 20)

Rondinax 35U for 35 mm film

Rondix 35 for 35 mm film

Essex 35 for 35 mm film


We never see how the Rondinax tank works because the lid is closed. The next video shows how the film is loaded onto the spiral from the centre and not dragged in from the edge as in a conventional developing tank. This mechanism, common to the Rondinax 35U and Rondinax 60, was an important part of the patents granted in the 1930s:

This one shows how the Rondix 35 works, with its brilliantly simple design


Search ‘Rondinax’ in YouTube