Please see “Photographing with Soratama” for information.
Here are tips to focus on the target using Soratama.
(1) Set to manual focus. (it does not mean manual exposure)
(2) Try to focus on the nearest object.
(3) After taking the step (2) above, try to move the Soratama lens back and forth until it is focused.
If you fix the extension tube 72, try to see if it can be focused with the auto focus mode.