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Amazing bino telescopes


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9 hours ago, Physopto said:

Aye, and many can see in the infra red and ultra violet as well. We need expensive equipment to do so. Life just ain't fair! 😀

More importantly (or more jealous-making) many of them can also fly!

Back on the psychological aspect of binocular observing, I suspect it's quite variable between individuals. I've never been overly fussed by bino viewing. It does have something natural and relaxing about it but only once I've got my eyes and the oculars into exactly the right position - and this takes some slightly stressful fiddling about. But then I have a very lazy eye which, on its own, gives a dismally soft image. Perhaps those with two good eyes get more out of the bino experience.  And here's one for the pot: how do dyslexics feel about bino viewing? They have no dominant eye.

Olly

 

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I just love amount of handles it has at the front - for one to brace themselves when having a first look :D

On topic bino vs mono, as stated - there is no perceived brightness increase, but there is a benefit to it. In the same way as observing a target for longer makes us see more so does binoviewing. Eye/brain system does not work like camera sensor - there is no single exposure - it is continuous feed and brain does all sorts of wonderful things to this. It has noise filter - you never seem to see the photon shot noise although there should be shot noise visible at levels of light eye is able to see (just a hand full of photons can be detected, I believe threshold is something like 6-7). Our brain sort of forms "residual image" - it remembers what it saw just a bit ago, and image sort of stacks in our brain - this is why prolonged observing helps see more - once we see one detail and "know what to expect" at that place - it's easier to see it. Binoviewing does similar thing - our brain can use noise filtering more effectively - if it comes from one eye only, maybe it's noise, but if both eyes detect it - it's probably signal.

Btw, I managed to see shot noise once, for anyone interested - here is how it happened. I was sitting in relatively lit up room (daylight no artificial light) - but there were some shades on windows so it was not overly bright. It was bright sunny day outside, so plenty of light there. I held Ha filter at some distance away from my eye (not very close but not at arms length either, about 20-30cm away) and looked thru it - I was looking at bright outside - thru the open terrace door.

Image thru the filter was distinctly deep red but it behaved as an old TV when not tuned to any particular channel - just that white noise. In this case it was "red/black" type of noise over the image changing rapidly (really much like TV noise).

I think that it happened because of lack of light coming from that direction while surrounding light levels were high enough to "turn off" brain denoise.

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I can't claim any credit or kudos for building it. I bought it from its owner when he was moving a long distance and had to make some hard choices on what to take and what to let go. The scope had been sitting in a shed in pieces for some time languishing and waiting to be refurbished, modded and upgraded or cannibalized for a new version. I was lucky enough to be in the right place at the right time and scrounged enough cash (and a 17mm Nagler) together to buy it. I figured you don't get the chance everyday to buy a 20" binodob 🤣

I based it back together, added a few minor tweaks and safety items. It's a bit of a pain and fiddly to set up compared to my other big dobs for instance I can have my 28 up and running in 10 minutes from arriving on site. I am slowly making small changes to how things work and fit together to make it svelte, it's a work in progress. I'm still getting my head around alignment, collimation and adjustment.

Views have superior depth in a binoscope, the planets, the moon especially and bright dsos. The biggest cons with a big bino is the double cost or double building. Recoat mirrors x2 + x2 shipping expenses, new EPs x2, secondaries and tertiaries x2, higher quality focusers x2 . Adds up real quick. 

I am very pleased to own it though, its a hell of a scope, a very well built scope with many clever well thought out nuances. I'll keep honing and polishing it over time. 😀

 

binodob2.jpg

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