Why couldn't a catadioptric or newtonian optical system be used in binoculars? (1 Viewer)

Mirador...you have that? Lucky dog. Extra hand-figuring, maybe.
They did make great and so-so, but Mirador's best was phenomenal.
They had a profound effect on Customs and Streamlines and ideas that
affected the whole Fujinon and Kowa lines. And...they made cool pocket
extra-wides with different brands on them. They sort of died.
I suspect it was a lack of appreciation for their very expensive machining
and build quality. What could be made affordable was absorbed into other makes.

Hi All:

Owing to all the interest in catadioptric and off-axis binoculars that I have seen posted here, I might suggest that interested forum members contact the Big Three and tell them they are foolish for not making such. I would only offer a word of caution relating to the hurdles they will have to surmount to put them into production.

1. You will need to show mathematically ($$$$) how such a system would provide a SIGNIFICANTLY better image than could be produced with a state-of-the-art in conventional binocular. And why the AVERAGE observer should even care.

2. For either Cassegrain or off-axis binoculars, you will need to prove to them that collimationally finicky systems, could be made to be infinitely more rigid than with current technology. Of, course they could be active systems and IS systems. But then, you would need to prove that Aunt Myrtle, and her bird watching friends, can—and WOULD—spent $20,000+ for the electronic and mechanical ad-ons, as well as providing a muscleman for each lady to hold the binocular up to their eyes.

3. The companies might also question the cost of the additional floor space required to house the additional lenses, prisms, mirrors, fixtures, and test equipment that weren’t needed … last year.

4. You would need to prove the headaches that come with making the various relay lenses and mirrors would be financially worth the effort.

5. Although you might enjoy the images from a system with a large central obstruction (with some not realizing what that means to an image), I feel trying to sell that idea to any one of the Big Three might elicit a great deal of laughter, after which they might show you a photo of a star field taken with an apochromatic refractor, in which stars looked like pinpoints, and another taken with an obstructed system in which the stars look like they were drawn with a crayon. Then, when you protested, they might show you that the better of the photos taken with SCTs, were taken with the corrector fitted with and off-axis mask. And please, don’t now jump on the off-axis band wagon; it’s just as foolish, and concerns itself with cheap Asian instruments that are targeted to those who are incredibly inexperienced.

It’s KNOWLEDGE that lets you know the tomato is a fruit.
It’s WISDOM that lets you know you shouldn’t put it in a fruit salad!

Thoughts like those flourishing on this thread can be very helpful when participants have a knowledge of the realities of lens design and the realities of instrument production.

Until then, I would encourage any member to make such an instrument as has been discussed thus far, and send it to Zygo that the benefits might be documented in an authoritative way.

Bill (your warm and fuzzy little curmudgeon) out |:x|


PS Once while working on an issue of ATM Journal, I received an article with the sender raving that he had designed a telescope in which ALL the rays fit into a TINY, TINY segment of the Airy disc. Along with the article, he sent me a spot diagram of his work. [In those days, Ray fans, OPD plots, and MTFs were out of the question for amateurs.]

This, of course, was too good to be true. Yet, this telescope maker was too excited to pay any attention to that negative and frivolous reality. And, I’m sure all his telescope making buddies were duly impressed.

With a little investigation, however, it was easy to see he how he had designed such a superlative system … HE DESIGNED IT AROUND ONLY ONE WAVELENGTH!

When I took his specs and dropped in the red and blue—he had designed it around .580 microns—it would have taken a bank of it least 9 monitors to capture all those rays. The system that was so wonderful in his head was worse than useless in the real world.

Was this a bad person? Of course not. He was just ignoring one of the most basic procedures in designing lenses. Reality bites, and I think a person who points out such folly is doing a favor, at least to those who care about the truth.

I don't believe anyone called for mass-manufacture of big reflector binoculars by Alphas.
So....don't worry.
It looks like a company or two and a few individuals have successfully overcome technical trouble.
It's not impossibly bewildering for hobbyist or manufacturer. The sales would be near nil, though.

Other than that, it's a big thingy, and there is no good reason why you can't just stick a
binocular viewer on a single mirror. Stereo vision doesn't mean anything after a few hundred yards.
except for comparing noise that differs per eye, in the cortex....bino viewers are fine for that.

It's been said...you're going through two 'air cells'. Not really, given the field of view.
If there's a big difference in the first hundred yards, you're in a place that makes any viewing pointless.

:cat:

OPTIC_NUT said:

I don't believe anyone called for mass-manufacture of big reflector binoculars by Alphas.
So....don't worry.
It looks like a company or two and a few individuals have successfully overcome technical trouble.
It's not impossibly bewildering for hobbyist or manufacturer. The sales would be near nil, though.

Other than that, it's a big thingy, and there is no good reason why you can't just stick a
binocular viewer on a single mirror. Stereo vision doesn't mean anything after a few hundred yards.
except for comparing noise that differs per eye, in the cortex....bino viewers are fine for that.

It's been said...you're going through two 'air cells'. Not really, given the field of view.
If there's a big difference in the first hundred yards, you're in a place that makes any viewing pointless.

Click to expand...

O_N:

Yes, thermal cells make a difference, even in hand-held binoculars. Even so, while it is a topic to know about, it is certainly not one to fret, or waste words over—at least as far as bird watching is concerned.

“Scientists have been aware of optical turbulence since English naturalist Robert Hooke in 1665 attributed the twinkling of stars to "small, moving regions of the atmosphere having different refracting powers which act like lenses." Astronomer William Herschel was aware of optical turbulence and explicitly adopted measures to cope with it, and observational analyses of the problem appear in the late 19th century . . .

Observatory astronomers around 1900 had identified atmospheric turbulence as a ‘FACTOR OF PRIME IMPORTANCE’ . . .”

I notice you poo pooed another of my assertions recently over on another thread. Thus, would I be out of line in asking you to post your specific optical credentials (other than your readings and amateur repairs) on the forum for all to see?

When I returned to this forum, you seemed to need to put your stamp of approval on what I said, or else lambast and correct me—“I tried, I really did.” I’m not unfamiliar with this modus operandi. There is someone on Cloudy Nights with the same agenda. If I could lay my sword on his shoulder and give him my experience, I would; maybe then I could have some peace. He has only been successful in stealing it with newbies and non-English speakers. But, he keeps trying.

So, I will leave you to build your fiefdom; I’m just trying to help. So, considering I have been severely and unkindly warned that to be here I must let you walk all over me and waste my time defending what I know to be true, I will leave you to your own devices. :cat:

Cheers,

Bill

PS Have another 100 feet of rope, on me.

"- WJC -----------------------------------------------------------

Yes, thermal cells make a difference, even in hand-held binoculars. Even so, while it is a topic to know about, it is certainly not one to fret, or waste words over—at least as far as bird watching is concerned.

“Scientists have been aware of optical turbulence since English naturalist Robert Hooke in 1665 attributed the twinkling of stars to "small, moving regions of the atmosphere having different refracting powers which act like lenses." Astronomer William Herschel was aware of optical turbulence and explicitly adopted measures to cope with it, and observational analyses of the problem appear in the late 19th century . . .

Observatory astronomers around 1900 had identified atmospheric turbulence as a ‘FACTOR OF PRIME IMPORTANCE’ . . .”

"---------------------------------------------------------

Well....it is important, but not relevent, your honor?

Was Robert Hook using binoculars??? NO It was a telescope he was referring to.

Those sections acting as lenses subtend areas that BOTH BINOCULAR PATHS SHARE.

Even more is know about it since "Star Wars" laser research and artificial stars and adaptive optics.
Those binocular FOVs share the same cell, except at edges.

Rant on if you like, but the two barrels are basically looking through the SAME CELL.

Imagine whatever hyperbole you like.
If I bring up technical detail and you imagine it is "lambasting"
I cannot help you. You bring out the emotional adjectives.
I'm just stating the science.

100 yards does not make a cell. And...the FOV overlap is already well underway.

I don't particularly care about my feelings or your ego.
Neither does the truth, whatever "truthiness" you gut-feel about things.
Optical Science and engineering are what they are, and so is atmospheric science.

The geometry of two barrels a few feet apart looking out hundreds of yards or light-years
is obvious and completely unavoidable.

There's too much folklore based on feelings that feel like science.

A little more recent background (than Hook):

Phenomenon of the 'cell', associated with astronomical 'seeing':

http://en.wikipedia.org/wiki/Astronomical_seeing

(turbulent layer, pertrubed wavefronts, r0 and t0, FWHM, )


http://www.wwnorton.com/college/astronomy/astro21/sandt/seeing.html

(can even happen with 0.1C difference in large scope barrel, but happens over miles of atmosphere)

("seeing cells,"....eddy lenses....millimeters to...meters wide..."swarm" in the sky)



---------------------------------

The geometry:

---take two tubes, 2 feet apart on center, and a 2 degree field of view

---at 100 yards, two feet is arctan(2/300) = 0.38 degrees
---but....for EACH barrel, that is about 0.2 degrees to the common centerline
(note that I am going "3 axis", as it were)

So.....if the fov is 2 degrees, and the two sides are truly parallel
1.8 degrees of the 2.0 degrees is already FULLY OVERLAPPED at 100 yards.

So...long before that you will not have seperate 'cells' for the two sides.
Maybe it will help with your barrels at first, but you should have left them to cool before you looked.


That's what I'm talking about. It is what it is.

Hermann said:

Is that the MTO 10/1000 telephoto lens? I've got one of those as well, with a later serial number (922xxx). I use it with an Intes prism diagonal and Zeiss Jena orthoscopics (26mm, 16mm and 10mm). At 100x the image is very good indeed. Used with a Leica zoom eyepiece (plus adapter) I get up to 140x, still at a very decent optical quality.

The MTOs are really nice and built to last. There were quite a lot on the market some 20 years or so ago, and many astronomers over here got them for use as a travel scope. They were lovingly called "Russentonne".

Hermann

Click to expand...

Where did you get the MTO and how much?

They were sold used all over the place after the fall of the Berlin Wall until about 2000. I paid something like the equivalent of $ 200 for mine - in mint condition, with all filters. Used it as a telephoto for some time, then as an astronomical scope.

Haven't seen any being sold over here in a while though. Seems like the astronomers who got one don't sell them, and the supply from the east seems to have dried up.

Hermann

Hermann said:

They were sold used all over the place after the fall of the Berlin Wall until about 2000. I paid something like the equivalent of $ 200 for mine - in mint condition, with all filters. Used it as a telephoto for some time, then as an astronomical scope.

Haven't seen any being sold over here in a while though. Seems like the astronomers who got one don't sell them, and the supply from the east seems to have dried up.

Hermann

Click to expand...

Wow. That is some fine optics for little money. I would imagine there are fine optics floating around Germany if you look.