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Author Topic: Astronomical binocular stuff  (Read 4913 times)

Offline Adondo

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Astronomical binocular stuff
« on: November 09, 2012, 11:23:02 AM »
This isn't camera related, but this thread is for a couple projects I've been doing on and off for the last couple of months. Mom was dying of cancer, so life got put on hold for a while. I'd work on this and a parallelogram mount in short snippets.

Here's a couple of photos of my Giant Garrett 100 mm binoculars I bought a while back. The things have phenomenal optics, and weigh a whopping 11 lbs. They're also 18 inches long. (Please pardon the cell phone pix. I will get REAL photos of both projects with the T2i soon, and post them)

Needless to say, holding them up to your eyes like typical binocs does NOT work.

I saw something called a "Sky Window" and copied the design. The mirror is a front surface type. (or first surface mirror) It's a bounce mirror for high powered argon lasers, actually, and was surplus on eBay for $25.

Due to weird physics of the behemoth binoculars interacting with the slanted mirror, this idea didn't work for the big 25x 'nocs; stars are short lines, terrain things are "smeared" images. The Garrett engineers explained why in a long email.

I bought another pair, their Gemini 12x60's, and shortened the mounting post. It now works GREAT, and you can sit in "microscope mode" and comfortably look at the sky all night. The 12x60's are dedicated to this setup now. They're too powerful for hand holding. Besides, I have Canon image stabilized 10x30's for general use.

The parallelogram setup was built for my Velbon 'pod. I have a 1940's Fred Hoffner self-leveling ball mount that I LOVE on the one post, and I had a second post handy. The parallelogram mount can be dropped into the pod in seconds. I used an 8 lb. salmon fishing trolling weight for a counter-balance, and the giant 11 lb. binoculars float around weightlessly. My idea was that I always pack the Velbon around anyway, so it's now a double duty binoc and camera 'pod. Photos to be posted soon.

Here's my "Sky Window"



« Last Edit: November 09, 2012, 11:26:20 AM by Adondo »

Offline zubbuz

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Re: Astronomical binocular stuff
« Reply #1 on: November 09, 2012, 11:26:58 AM »
That's rather fascinating.... And damn those things are huge....
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Offline Adondo

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Re: Astronomical binocular stuff
« Reply #2 on: November 09, 2012, 11:44:00 AM »
I found a few more cell phone pix here at work. :)

Folded up for travel. The counter-weight bar is solid steel, and weighs 2.5 lbs. by itself, reducing the need for a bigger weight-ball. The black thing is the fishing weight, which is PVC coated. (It was only $20)



The Velbon camera head works good, and gives the 'nocs movement at the end of the arm.


The P-mount in the Velbon 'pod.


The huge 'nocs mounted and ready. They seem to be weightless, and move around easy. They can "float up" to about 7 feet high, so they can angle up for star viewing while standing. Sitting in a chair, such as a reclining REI camp chair makes star viewing comfy to maybe 80 degrees up. For terrain use, you can either have the 'nocs aim over the tripod which does work best, or sideways to the pod.


The optics can easily resolve tower lattice work at FIFTEEN MILES AWAY. I've never had anything like them before. Of course, those 100mm objectives are over FOUR INCHES in diameter!! We could even see people walking around on the radio tower site from my house. Having two eyes working makes an enormous difference too. Shutting an eye, and the tower's lattice work becomes vague grey matter.

Offline AndyCivil

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Re: Astronomical binocular stuff
« Reply #3 on: November 09, 2012, 09:23:47 PM »
Having two eyes working makes an enormous difference too.
I guess that's true, but it struck me looking at those, that the best benefit of BInoculars is stereo vision - a perception of depth - but the stars are so far away that any thought of depth is out of the question! Seems like a waste: you've got two lenses magnifying exactly the same thing! Wouldn't it be cheaper to have just ONE barrell, and split the result to send half to each eye?

Offline Adondo

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Re: Astronomical binocular stuff
« Reply #4 on: April 26, 2013, 10:35:45 AM »
Wow, how did I miss this for so long? I guess I'll bump the thread anyway.

It's true that depth perception ain't a' gonna' happen with stars light years away, but your two eyes still feed you more info.

On tests we've done, (A buddy and me) we noticed in terrestrial use, the difference it makes. At a radio site that GPS's about 15.5 miles away from my house, with one eye in the big binocs, or using a spotting scope, and you see gray things sticking up from the hill top. Use both eyes, and those gray sticks become towers with discernible lattice work. It's all processing within the brain.

On astronomical websites, or Astronomy magazine, there's quite a bit of discussion about looking at the sky with binoculars. It's not just big telescopes with the astronomers. Using both eyes is just better.