Step-up ring and Step-down ring
The diameter of the “soratama 72” is 72mm. To fix it onto a camera lens, please use step-up ring which are sold separately. For example, if you are to fix the “soratama 72” onto a 52mm diameter lens, please use a 52-72mm step-up ring. If the diameter of your camera lens is way too short, use a combination of two step-up rings such as “37-58mm” and “58-72mm.”
In case where the diameter of your camera lens is longer than 72mm, please use a step-down ring such as “77-72mm.”
If the diameter of your camera lens is just 72mm, Step-up rings and step-down rings is not needed.