Problem:- I cannot find the second pair of prism tilt screws on a pair of Andrews 20x80 Triplet binoculars. I can find the front pair near to the eyepieces, but not the "rear" set, at the other side of the prism housing. I've eased up the rubber all the way around and nothing found. Can someone point them out to me?
Background:- A friend recently acquired a secondhand pair of these binoculars. They seemed fine but I suspected the collimation could use a tweak. Additionally, at the top of the field of view in both left and right eyes, the image was out of focus - didn't worry my friend, but I was sure it could be better. I've just learnt how to collimate binoculars and have worked through my four pairs over the weekend. They were many and varied, but I got the hang of it. The 30x100s were particularly difficult - horizontally, the images were too far apart, so I had to tackle all four screws. It took a while, but I'm pleased with the result and look forward to a cloud-free night with no other commitments, to test them.
So I tackled the Triplet pair today. Vertical collimation was out and horizontally was a little in the wrong direction. However, I wanted to make a major adjustment to see what effect that had on the out of focus top of image problem. Well, I finally ended up in a situation where, if I release each "front" tilt screw, the images are horizontally way out of collimation and, as I push in each screw, it only gets worse. I can achieve vertical collimation, but horizontally, I'm stuffed! I've given up worrying about the out of focus problem - I'll have to come back to that. If I could find the other tilt screws, I think I can solve whatever has happened. I have tried sharp taps on the prism housing, but that has no effect so the prisms seem to be seated well.
Very grateful, in advance.
Yes, but the way, I have to read this in detail tomorrow since it gives lots more information that I have at present:-
http://www.cloudynights.com/item.php?item_id=416
If everything fails, can anyone recommend someone in Melbourne who can collimate them and check them out for me (and show me what I've done wrong at the same time
) - one of the stores?