B Harris 1 Posted May 2, 2020 (edited) Hello, After 12 years, I am getting back into UW Photography, I have just picked up a Subal ND20 Rig/Ports and other items. Just waiting to be delivered. I need to get an extension ring, but was wondering if the Bayonet Type is 3 or 4 ?? I would have thought its a Type 3 as its an older housing, but double checking. Keep safe Regards Brian UK Edited May 2, 2020 by B Harris error Share this post Link to post Share on other sites
scuba_d 5 Posted May 2, 2020 (edited) I had Subal ND2 and originally comes as type 3 and I believe, it is impossible to fit type 4 in it, even if you want as the opening and internals would not allow the conversion. However, I have Subal ND7100 and another one for Nikon D90, both type 4, so I can measure the diameter of the porthole and let you know. Edited May 2, 2020 by scuba_d Share this post Link to post Share on other sites
scuba_d 5 Posted May 2, 2020 Take a look at this explanation: SUBAL PORT MOUNT IDENTIFICATION Share this post Link to post Share on other sites
B Harris 1 Posted May 2, 2020 Sorry I meant ND20 Housing Share this post Link to post Share on other sites
scuba_d 5 Posted May 2, 2020 I have just measured the porthole of my type 4 housing and the diameter is 110 mm, so yours should be 100 mm. Share this post Link to post Share on other sites
