Bino Mirror Mount

I have an old pair of 16x50 binoculars that I bought for $15.00 at a flee market a few years ago. Sixteen power is way too much power for me to hold by hand and it may be a little too much magnification for stargazing, but I have had some success using them with a tripod or the parallelogram I made for the Coke bottle bino's. Both the tripod and the parallelogram work well when used at the horizon or a little above, but can get uncomfortable as you look higher and higher. One solution is a binocular mirror mount. I've seen two versions of these mounts, both have the binos aimed down at a mirror which is reflecting the sky. The first type has the binos and the mirror mounted at a fixed angle of around 45 degrees, and is aimed in altitude by tilting the whole assembly on a tripod or similar mount. With the other type the binoculars are mounter at a fixed angle of approximately 45 degrees and you tilt the mirror up or down to aim in altitude. Both types use a swiveling base for aiming in azimuth. With either of these mounts you can observe from horizon to zenith while standing or sitting in a relaxed and comfortable manner looking down.

The mirror needs to be a first or front surface mirror. Most mirrors have the reflective coating on the back of the glass. The glass protects the coating but because the glass reflects about four percent of the light hitting it you may see a ghost reflection when looking a bright objects. There are several web sites that offer first surface mirrors. The 7 inch by 8 inch by ¼ inch first surface plate glass mirror that I used cost a little less than $50.00 including shipping and shows some distortion using the 16 power binoculars. I'm not sure how much is caused by ripples in the mirror or imperfections in the inexpensive high powered binos. Probably a little of each. Using a decent pair of 7x50's gives very good results and I suspect a good pair of 10x50's would also work well. They do offer first surface mirrors made with precision ¼ wave glass if you plan on using high power (15 to 20) binoculars, but the price jumps up to around $450.00 for the above mentioned size.

                                                                                                                                                       Bino mirror makers usually mount their mirrors by gluing them to the platform but I was worried about dirt, fingerprints, and other debris damaging the delicate reflecting surface so I made it so the mirror can be flipped over. This way if I use it at an outreach event or in a dusty area I can position it with the glass (protected) side up.