A Few Basic Questions

A Few Basic Questions

I have a 63 year old pair of B&L 7x50's individual focus. They are marvelous binoculars, bright, and sharp.

There is a hinge assembly between the 2 OPA's to swing them for IPD adjustment.

What happens to the image when you swing the OTA's?

Is the convergence affected?

Is the collimation affected?

Is there an angle of swing beyond which the image would not look upright?

My reason for asking these questions is that I am designing a bi-Newt based on a pair of Meade 114NT's.

I wonder what needs to be adjusted for convergence and whether a pair of Newts whose eypieces face each other can achieve a correct image?

Stu

Hello:
It is possible to get matching images with Newtonian binoculars. They won't be right-side-up, which is normal for a Newtonian.
With the hinge method of adjusting interpupiliary distance, it is critical that the two optical axes are aligned with the hinge's rotation axis as well as being aligned to eachother. From what I've read, just getting the two optical axes aligned to each other with both scopes in collimation is quite challenging. This may be why (to my knowledge) no one has done a hinged bino-newtonian. Apparently there are other ways to skin this cat. One of them is that if you want, say, 4" binoculars, get a 6" scope and a binoviewer.

Cheers
Mike Connelley

Hi Stu, I've contemplated this myself but decided against it because the viewing is only comfortable over a limited range. But here is some infor which might be helpful.

Here is a group that you might want to join. I didn't spot you on the members list.

http://groups.yahoo.com/group/binewt/


E-mail me offline and I can get you a source of 1 1/4 inch 90 degree diagonals that don't have the focuser side which might work for you.

Dave