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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Ultra wide binoculars (1 Viewer)

Mono

Hi!
Staff member
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Europe
I'm thinking of getting some ultra wide binoculars for whole sky gazing.
The three on the market seem to be...
Helios 2x40 c£90
Orion 2x54 c£140
Vixen 2.1x42 c£250

Anyone have any thoughts or experiences with any of the above.
 
Orion are the widest, though the sir eyepieces seem to hit my nose a bit. Binobandits work well to make the view more immersive. Just gives you more stars than you can normally see, useful for finding things under urban skies or make urban skies a bit more interesting.

Peter
 
I'm thinking of getting some ultra wide binoculars for whole sky gazing.
The three on the market seem to be...
Helios 2x40 c£90
Orion 2x54 c£140
Vixen 2.1x42 c£250

Anyone have any thoughts or experiences with any of the above.
There is quite a bit of discussion about these on Cloudy Nights, there is plenty for you to read there eg:







Happy reading!
 
A bit late to the game but I recently bought a 2x54 (labeled "Omegon" which seems to be the store brand of the German "astroshop.de". I love them. Quality is excellent, views are incredibly wide. I can almost fit the whole constellation "swan" in it (minus one star at the wingtip). I'd highly recommend it.
 
I'm thinking of getting some ultra wide binoculars for whole sky gazing.
The three on the market seem to be...
Helios 2x40 c£90
Orion 2x54 c£140
Vixen 2.1x42 c£250

Anyone have any thoughts or experiences with any of the above.
I do not have any experience with the binoculars on your list. My son and I use Leica Trinovids 10x42 and Zeiss Conquests 10x42 for both day and night. Please keep us posted on your choice and experiences.
 
There is a review by Dipperdapper where the Helios 2x40 was preferred to the Svbony 2.1x42 version.

Not sure how the 2x54 compares.

B.
 
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I am looking forward for a prism binocular with ~20 deg TFOV. A 3x20 with a flat field eyepiece. Wouldn't that be awesome?
 
The 4x22 Libra/Dowling and Rowe roof prism binocular has a fairly flat 16.5 degree field.
Either central focus or independent focus.

The Soviet 4x16 has a fairly flat field of about 18 degrees plus.

It might be adapted to 3x12 with a 24 degree field?

I am not sure if the VisionKing 5x25 could be adapted to 4x20 with a 19.5 degree field.

With suitable eyepieces and mirrors a 3x20 20 degree flat field binocular could probably be made at home.

Regards,
B.
 
I have searched for Libra 4x22 earlier but have not found it available anywhere.
And I have Visionking 5x25. Very useful binocular but only ~25% of the field area is sharp, so it's not very good for astronomy.
 
I am looking forward for a prism binocular with ~20 deg TFOV. A 3x20 with a flat field eyepiece. Wouldn't that be awesome?
Absolutely, but alas near to impossible.
To avoid vignetting with a 20° TFoV the prism stop would have to be relatively large and the prisms correspondingly so.
Prism cross sections are significantly larger than the prism stop and, according to Holger Merlitz, the glass path in a a Schmdt-Pechan prism is 4,6 times the prism stop diameter, so that would necessitate a somewhat "slower" focal ratio and long focal length 60° eyepieces much bigger than the objectives!
Most devices with low magnification have very small AFoVs, only about 38° on my 3x12 Zeiss monocular.
Despite their shortcomings, Galilean binoculars are probably the better solution.

John
 
Beechers Mirage 4x20 15 degree field.

Libra/Dowling and Rowe 4x22 16.5 degrees.

Soviet 4x16 18 degree field.

Bushnell 4x21 (Actually 3.5x21) 18.5 degrees.

Bushnell Xtrawide 5x25 (Actually 4.4x25). Large field but cannot remember size.

1.65x Minolta afocal adapter very flat field of more than 30 degrees.
There are even bigger afocal adapters, Ricoh etc. but too wide for a binocular.

Minolta scope adapter plus 28mm photo lens. 22 degree field. Good image but some false colour near edge.
Because the scope adapter has a wide range dioptre and the lens focuses the magnification seems to be 3x, but maybe varies to 2.8x.
This combination focuses to 9 inches from the front element to well past 'infinity'.
At night rather dim, and I am not sure of the equivalent aperture.
Will see in daytime.
This easily hand held and rather small size.
A bit too wide to make a binocular, but there may be other photo lenses around 30mm focus that could be made into a binocular with two scope adapters.

May try a 35mm lens.

Galilean binoculars are usually small AFOV.
But the optics listed above go up to 65 degrees or more AFOV.

Regards,
B.
 
The Vivitar 28mm lens plus Minolta scope adapter/monocular converter is 97mm long and 62mm wide.

So for someone with an IPD of 64mm or more two could make a binocular.

Although the field is 22 degrees or slightly more, the edge performance is poor.
The image is O.K. to 60% from centre.
The central magnification is 3x and the full Moon in a clear sky was good.
There is weird internal vignetting but the monocular is about 3x10 with just over 3mm exit pupil.
A Minolta 28mm lens might do better.
Although this demonstrates wide fields are possible at 3x, there is too much glass for a sensible binocular.

The Vivitar lens was made in November 1980 from the Japan oval sticker code and is multicoated.

A good 3x20 flat field binocular could, I think, be made with two flat field eyepieces and mirrors.
The problem is at 20mm aperture the focal length of the objectives is about 70mm, needing 23mm fl eyepieces.
I am not sure how large such a flat field eyepiece would be.
60 degree eyepieces should give about a 20 degree field.

Somehow 3x binoculars are not generally produced, although there was a tiny prismatic Leitz 3x binocular with probably a small field.

3x opera or field glasses exist with small fields.

Regards,
B.
 
Using a high quality Minolta 35mm f/2.8 lens made about 1968 and the Minolta monocular converter, I got much better results than using the Vivitar 28mm lens.

The Minolta lens has 8 elements in 7 groups and seems to have Minolta achromat two layer coatings. It looks new and has the two caps, hood and case. The focus is a bit too sensitive so it is a bit difficult to maintain focus when used visually.
It is nearly all metal and glass.

The magnification is 3.5x and very near the edge there is angular magnification distortion, It behaves as a 3.5x12.5 monocular.
The exit pupil is about 3.5mm.

The real field is 18 degrees.

The image is good, and the magnification high enough to see quite good detail on the almost full Moon.

It is a genuinely useful monocular.

The length is 91mm and the width 58mm. So someone with a 60mm or larger IPD could make a binocular using two.

A 3x30 modern coated Galilean or Dutch binocular has a field of 7 degrees without glasses and 5 degrees with glasses.
I know this is a good binocular as I saw a Mercury transit with it using a safe solar filter.
Mercury was 12 arcseconds across and the tiny black dot was followed periodically over the long time of the transit.
A Mercury transit is much blacker than sunspots, which have a grey penumbral edge.
The AFOV of this 3x30 is about 21 degrees at best.

There are shorter Galilean binoculars with wider fields, but much smaller than the Minolta monocular set up.

Regards,
B.
 

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