Bino Viewing made easy

[erick (Eric)]

I've been wanting to do this project for some time so that I could easily use my binoculars for objects high in the sky.

With the strength of the Aussie $ against the Greenback, I thought it was time, so I bought a front surface mirror from these folks:-

http://www.frontsurfacemirror.com/BounceMirror.htm

I bought the ten inch square gimbaled mirror.

Today I built up a rough test rig to see how it would perform with my 12x60 and 20x80 binoculars. I used part of my home-made binocular mount when meant that the binoculars weren't quite placed in the ideal position (which, from examples on the 'net, seems to be pointing down at 45 deg). In fact they were much closer to horizontal.

I also bought a swivel mechanism from Bunnings (the small version is around $20) You can see how I put it all together - nothing very fancy.

I had to raise the whole lot up to eye level but it was very comfortable to use. I can rotate the lot on the swivel, I can tilt the binoculars up and down (normally they would be fixed) and I can tilt the mirror.

Obviously, tilt the mirror and/or binoculars too much and it starts to run out of mirror surface. However, I have a sense it will give me from Zenith down to around 30 deg altitude for both the 12x60 and 20x80 binos.

I got as far as observing the clouds and the daytime moon (and snapping a poor pic through one barrel to compare with the small image seen in the mirror).

Unfortunately 100% cloud tonight has ruined any dark testing

I'll do some testing and think of an improved design, including timber that will stand up to the conditions. I certainly will look to fit heating to the rear of the mirror - it will dew up quickly. Probably best to also fit straps to the objectives and eyepieces of the binos and run the lot off one controller.

Have to work out how to protect the mirror surface when not in use.

Thanks for looking.

[DavidU (Dave)]

Excellent project Eric.I must get around to doing this setup.
It must make the viewing less of a pain in the neck!

[Bobbyoutback]

Hi Erick ,

Very interested in your project , that link didn't work for me ?

I have a set of big binoculars that need some light , lazy Bob can't handle them so they just sit unused in a dark cupboard .

[erick (Eric)]

Originally Posted by Bobbyoutback

Hi Erick ,

Very interested in your project , that link didn't work for me ?

Hmmm - works for me. See if you can get it working. There are other suppliers if you Google "front surface mirrors". The one I really wanted to use lost me when I couldn't get their online shop to work? But I am happier with this one, having found the mirror on a gimbel - saves having to design a way to move the mirror.

I have yet to test on stars/nebulae etc. So cannot say how good the mirror is as yet. One mirror supplier (not the one I bought from) wouldn't guarantee performance above 18x mag.

These are available commercially (not cheap):-

http://www.tricomachine.com/skywindow/

These folks support up to 20x mag with their mirror. They however sell a 9x60 in their bundle.

[Bobbyoutback]

Originally Posted by erick

Hmmm - works for me. See if you can get it working. There are other suppliers if you Google "front surface mirrors". The one I really wanted to use lost me when I couldn't get their online shop to work? But I am happier with this one, having found the mirror on a gimbel - saves having to design a way to move the mirror.

I have yet to test on stars/nebulae etc. So cannot say how good the mirror is as yet. One mirror supplier (not the one I bought from) wouldn't guarantee performance above 18x mag.

These are available commercially (not cheap):-

http://www.tricomachine.com/skywindow/

These folks support up to 20x mag with their mirror. They however sell a 9x60 in their bundle.

Thanks Erick appreciate the reply .
Look forward to your comments Sir .

Will check those sites , good on you for posting them , like backing for at least 20X

Cheers
Bobby.

[Paddy (Patrick)]

Now that's a bit of lateral thinking Eric. I imagine it would take a few mental gymnastics to be able to point it at things until you get the hang of it, but how clever!

[Lester]

Top bit of DIY Eric, I bet most people have had some sore necks from binocular viewing of the night sky.

I will look forward to your report on viewing the night sky.

[erick (Eric)]

Grrrr! I've been trying to get out. Had 30min earlier with the 12x60s - Moon and Jupiter. Then busy again inside.

I can say the view was excellent - no evidence the mirror was in the light path.

Just going to try once more with the 20x80s before beddie-byes. Now the tennis courts have shut down their lights, I'm going to see if I can locate NGC253 which should be up near the zenith now.

UPDATE: That will have to do for tonight. Yes, the mirror is also invisible with my 20x80s, at all angles. Perhaps better binoculars would detect it was there. Couldn't spot NGC 253 but the Moon was shining brightly. But 47 Tuc looked nice. Yes, a bit tricky, at first to move around the sky. Tip up and down makes sense, but rotating on the swivel base produces a strange movement of the image - in essence, a parabolic curve of motion, I tink. But it is great to have a nice stable image to look at. With the 12x60s, I earlier tracked a satellite well across the sky. My rough mount is a bit unstable and needs some work (actually a full rebuild to a better design is warranted - with the binoculars fixed at 45 deg down, I think).

But I think the mirror is doing a great job!

[zumka (Daniel)]

Hi Erick,

Great design !!!

I'm working on the similar project for my AOE 25x100 binos, based on the Craig Colvin design

http://www.craigcolvin.com/Astronomy...larMirror.html

Everything is going well except mirror part, can you suggest where would be better to order it ? I know you already mentioned couple of sources in your original post but they all oversees any local ones ?

thanks

[erick (Eric)]

Zumka, work out the size carefully. Cut out coloured paper the size of various mirrors and hold it in front of your binoculars, at various angles, and see what you can see. It doesn't take much tilt before your big objectives will start collecting light from above and below the mirror's edge, if the mirror is too small. If you are in the dark, then that just means you lose some light in the view - but if the will pick up light or something of a light colour above or below the edge, that will interfere with your viewing. But with that design on a tripod, you can tilt the base plate and therefore keep the mirror from an extreme angled position.

I only found overseas suppliers and the one I used was a good price and shipped very quickly and securely.

Why don't you contact Mark (Satchmo) and get a quote for a nicely ground flat piece of glass. He can also recommend someone to coat it in Australia, I would expect. You might get a top quality local mirror for a very respctable price.

Also your mount will have to be very robust for that size and weight of binoculars.

[scopemankit (Chris)]

I made a binomount for a large Tasco bino. The source of the flat topcoated mirror (7"X12") Was an industrial photoscanner used for reproducing large illustrations.
It works very well.

[erick (Eric)]

I always wanted to get my hands on a big dead photocopier to nab its mirror. Instead I have had two mirrors from overhead projectors in my cupboard for a year wondering how to align them - one for each objective. No dead photocopier ever turned up, so I decided to give up and spend the money on a mirror.

Well done Chris on the mirror. Nice looking mount as well.

[zumka (Daniel)]

Originally Posted by scopemankit

I made a binomount for a large Tasco bino. The source of the flat topcoated mirror (7"X12") Was an industrial photoscanner used for reproducing large illustrations.
It works very well.

Nice design Chris. How do you find viewing with large binos via mirror ?

[scopemankit (Chris)]

Thanks Erick & Daniel,
You can actually notice the drop in light due to the extra reflection.

[zumka (Daniel)]

Looks like I better invest my money in to good tripod.