First light last night with my new Orion Premium Linear Binoviewer used on my Orion 10 inch Dobsonian telescope. What excited me about his binoviewer when I got it was that it claimed not to need any in focus – an issue that has meant other binoviewers I have tried only work if a Barlow lens is also used which means they only work at high magnifications. The whole point (in my view) of using Dobsonian telescopes are the immersive wide angle views – and you need the wide angle at least initially with an object to find it in a Dob when you are star hopping!
Great news! The Orion (USA) Premium Linear Binoviewer does come to focus in my Orion UK (different company) 10 inch Dobsonian. In fact I needed to use a 35mm extension tube – although that is common too with eyepieces in this scope so does not imply that the binoviewer increases out focus. So I think the manufacturer’s claim that no extra in focus is required seems to be supported on this test.
I had more of a problem bringing images of the Moon and a couple of stars together with my two eyes in the binoviewer – I put this down to lack of experience. There were times when the Moon images did come together and then suddenly the Moon would be significantly brighter.
Mind you, I am being a bit unfair on the binoviewer here. Due to the Moon being located awkwardly behind a tree, I had to place the scope in an awkward position to get a view and my own body was somewhat awkwardly positioned too – so that it wasn’t easy to view properly through the binoviewer.