I have an Olympus PT-EP10 underwater camera housing with a glass front port to which I'd like to be able to screw-in and remove a 67mm threaded INON underwater macro diopter.
The diameter of the front exterior glass port is 90mm and the lens barrel inside the port is 70mm.
Ideally, I'd like to find a thin 90mm diameter metal or durable plastic ring with inner threads of either 82, 77, 74, or 72mm--as all these diameters are wider than 70mm, and are easily acquirable sizes for step-down rings. (e.g. 77mm to 67mm step-down rings.)
Unfortunately the plastic rim around the front of the glass port is unthreaded (what was they thinking?) and (except for one thin mm) angled and, knowing no other clever way to attach it, the ring will have to be made of a material that can handle salt water and easily bonds to, but does not fog, glass.
Any ideas how to acquire such a ring, or any alternative suggestions?
Thanks, I appreciate your consideration,
The diameter of the front exterior glass port is 90mm and the lens barrel inside the port is 70mm.
Ideally, I'd like to find a thin 90mm diameter metal or durable plastic ring with inner threads of either 82, 77, 74, or 72mm--as all these diameters are wider than 70mm, and are easily acquirable sizes for step-down rings. (e.g. 77mm to 67mm step-down rings.)
Unfortunately the plastic rim around the front of the glass port is unthreaded (what was they thinking?) and (except for one thin mm) angled and, knowing no other clever way to attach it, the ring will have to be made of a material that can handle salt water and easily bonds to, but does not fog, glass.
Any ideas how to acquire such a ring, or any alternative suggestions?
Thanks, I appreciate your consideration,