big binoculars

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mike_wilson73
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big binoculars

Post by mike_wilson73 »

I am looking to buy a big pair of tripod mounted binoculars for looking at planets, comets etc. Can anyone recommend what I should buy? My budget is £2000.
David Frydman
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Post by David Frydman »

Dear Mike,
Can you confirm your budget is two thousand pounds.
If so maybe look at secondhand big Fujinons although the 6 inch would probably be more than this or big Vixens.
I think that the importers of the Fujinons in the U.K. may have improved big chinese binoculars to improve the quality and reliability.
If you confirm your budget i will look into this further.
Regards, David
David Frydman
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Post by David Frydman »

Look at Monk Optics,
Regards, David
David Frydman
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Post by David Frydman »

Also Sherwoods for Helios Quantam Series.

I am not sure who imports the Vixen 125mm binocular telescope or large binoculars on tripods. You may have to get a used one for £2,000.

The Nikon 120mm are probably too expensive?

The Vixen 150mm in 25x or 40x probably 45 degree inclined prisms are the best but even used probably beyond the budget.

With the chinese ones you MUST TEST THEM before buying as they almost certainly vary in quality.
This also applies to any binocular but particularly chinese binoculars.

The Miyauchi 100mm and Opticron similar are also a possibility.
Some have interchangeable eyepieces or turret eyepieces.
I would not get an ex WW2 giant binocular as they have suffered from old age and anyway the coatings etc. were not very good.

Regards, David
David Frydman
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Post by David Frydman »

There are or were Russian 15 x110 I think, wide field but too large exit pupil and too low magnification border guard binoculars.

I have 15 x70 Quantams which are very impressive but much smaller than the ones you are looking for.

Regards, David
David Frydman
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Post by David Frydman »

Apparently the 20x120 Nikons are the best you can get.
However, as you want to view planets I would get ones with interchangeable eyepieces up to high power. But they must be perfectly collimated.
David
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Post by David Frydman »

The Quantam 7.3 25x, 62x 100 straight through or
Quantam 7.4 25x angled seems the ones to go for.
Both can also use 1.25 inch eyepieces.
I would go for Quantam 7.4 inclined eyepiece binocular plus optional finder, see OVL, and a pair or two pairs of 1.25 inch eyepieces. Say giving the standard 25x and then 50x and 80x even 100x.
But you must buy it from someone who can check the collimation is perfect and that the optical quality of both barrels is top notch.
This is a tall order.
You put this in Absolute beginners so may be you won't have the ability to test these binoculars fully. You should find someone perhaps a local astro club member who can do this.
It is likely that if you buy them at random they will not be perfectly collimated and they won't take 80x or 100x as they should.
Also they should be collected by you preferably from a local shop as they may go out of collimation in transit.
Additionally if you move them a lot in use they may also go out of alignment.
The Nikon 20x120 are claimed never to go out of alignment but they are very expensive and only low power.
So not an easy problem to solve.
Whatever you do test them fully before buying.
Regards, David
David Frydman
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Post by David Frydman »

Being realistic, none of the above binoculars would give good views of the planets except possibly the Vixen 125s.
The reason is the planets need a magnification of 150 to 200x to observe them properly.
For a beginner to expect a binocular to achieve this is unrealistic.
Firstly the collimation would not be good enough and
Secondly the magnification is not high enough.
It would be better to spend £1,000 to £1,500 on big mounted binoculars and £500 to £1,000 on a planetary scope, perhaps an 8 or 10 inch high quality Dobsonian or a 6 inch f/8 refractor.

The other approach is to use a high quality binocular viewer such as Denkmeyer ? and an 8 inch SCT or similar. Here you would be using both eyes but on one scope. Or such a scope and a big mounted binocular if funds allow.

6 inch f/8 custom binocular telescopes have been made by Peter Drew and you might find one of these.

Also reversed Newtonian binoculars in 6,8, 10 inch and bigger. You look downwards into the instrument away from what you are pointing at.

So not as easy a question to answer as might first appear.

Regards, David
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Post by David Frydman »

The widescreen centre sells the Vixen BT 125 A binoculars for £3,600 list. I am not sure if this includes the tripod and mount.
Suggested eyepieces range from 30x to 58x.
This is not enough for planets, but I suspect the binocular telescope is good for 150x. It takes 1.25 inch eyepieces.
You would have to make sure the binoculars were collimated at the highest magnification perfectly.
For £2,000 one would have to find a secondhand Vixen BT 125 A.

Regards, David
mike_wilson73
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Post by mike_wilson73 »

Hi David

Thanks a lot for your in depth answers to my binocular question, given me a good few options to investigate!

Will look into second hand Vixens to start with. Also found this website: http://www.bigbinoculars.com/ which has a good selection, although it is a US site, not sure if they will send overseas.

Thanks
Mike
David Frydman
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Post by David Frydman »

Dear Mike,
Don't even think about buying binoculars from abroad except the Nikon 20x120.
They will arrive out of collimation and you will wish you never bought them abroad.
If you trace a secondhand Vixen 125 make sure you bring a pair of matched 150x eyepieces to test them. If you have not got enough experience to check the collimation take someone with you who has.
It may be they are f/6 giving a focal length of 750mm. For 150x you would need 5mm eyepieces preferably wide angle or extra wide angle.
If you wear glasses when using binoculars you will need long eye relief eyepieces.
Regards, David
David Frydman
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Post by David Frydman »

The Vixens are 760mm focal length.
Surprisingly they seem to be achromatic doublets whereas the chinese 100mm are advertised as triplet semi apochromat.
However, I think the Vixens will be of consistently high quality whereas the chinese will vary.
I also think the Vixens will maintain collimation but the chinese won't.

I used a 123mm doublet f/5 refractor for years and it gave very good images at 145x. It was good on Saturn and Jupiter but not nearly as good as a long focus refractor or 6 inch f/8 Newtonian.
So the Vixens will be a compromise for planets but should give good views.

David
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Post by David Frydman »

Besides the fact that you should not buy binoculars from abroad, there is also the not so small matter of duty. VAT and insurance.

I cannot emphasise enough that you have to physically test the binoculars yourself or with a knowledgeable friend before you part with any money.
Don't test binoculars and then buy another new boxed identical item. They are not identical and there is a good chance the new boxed binoculars are out of collimation.

Regards, David
David Frydman
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Post by David Frydman »

Also if you find a secondhand Vixen 125 make sure that say 5mm or 6mm wide field eyepieces reach focus on the binoculars.
I am not sure if all eyepieces are suitable or mainly Vixens own suggested ones.
David
David Frydman
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Post by David Frydman »

Vixen LVW eyepiece 5mm about £198 each
Baader Hyperion 5mm £92 each, but I don't know if these are a suitable match for Vixen 125 BT.
There are so many eyepieces and I don't know what would suit the Vixen 125 as high magnification eyepieces.
Regards, David
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