It only has a male thread that I can put in my T ring but then I can't attach anything after that. With other filters it would go camera, t ring, filter, flattener/reducer, telescope.
Is there any fix to this at all? Seems odd that Optlong only threads one side of a filter. How else do other people use these?
Edited by pcardinal42, 22 November 2020 - 10:18 AM.