Japanese extra wide binoculars

[avtaram]

Bought these from Astro Buy and sell.

Theres no makers mark but on the hard case they come in it has "made in japan".

On the binoculars on one side it has " fully amber coated " and on the other " 7 x 35 extra wide angle field 11* no. 73581 ".

Does anybody know the make of these.

They look pretty old and well used and there are some marks on the optics but these don't seem to affect the view.

In daylight they give nice sharp views without any noticeable distortion at the edges.

I tried them out tonight first on the Moon and the view was sharp to the edge as far as I could see.

There was some CA (orange) just on the lower edge.

Panning around the sky the stars were also sharp to the edge without any noticeable distortion at the edge, but the image was dimmer than in my 10x42 Praktica, which I suppose is to be expected.

As far as the FOV is concerned I think it is quite close to the stated 11* as I could get Regulus and Algieba in the same FOV with some room to spare.

Panning around Polaris I noticed just below it an asterism in the shape of a question mark ( ? ) , something I had not noticed before, obviously more evident due to the greater FOV.

Looking on Luminos the stars forming this asterism are in the Constellation of Cepheus consisting of:

2 umi ( not sure if this is correct as its in Cepheus and not Ursa Minor but thats what it is listed as in Luminos, ngc 188 is just below this star .)

HR 306

HR 8938

HR 8546

HR 8736

HR 8748

HR 8702

Can't wait to see how many more of these asterisms I can come across using the extra wide angle bins.

Avtar

[Alfian]

Hi, this may not help at all, but when I saw the distinctive eyepiece and focuser marking it raked up a memory of the PrinzLux binoculars - like these

http://www.ebay.co.uk/itm/LOVELY-VINTAGE-PRINZ-PRINZLUX-8-X-40-BINOCULARS-WITH-LEATHER-STRAP-/171256924905?pt=UK_Photography_Binoculars_Monoculars&hash=item27dfb54ae9

Not quite the same and I cannot find any PrinzLux 7x35s. Good luck with the search.

[avtaram]

Thanks Alfian.

Yes they do look very similar to the Prinzlux binoculars.

I will carry on the search just out of curiosity.

Avtar

[jabeoo1]

Avtar, they sound really nice.  Low magnification wide field can never be understated. Good find by the sounds of it !

I have seen a fair few Japanese binoculars in charity shops on my travels around, I always wondered whether there was any value in the view they can deliver.  By what you say it seems they are worth a closer look next time. 

James

[NGC 1502]

Any of these look like yours ?  http://www.binocularstelescopes.info/store/extra_wide_binoculars.html

Nice bins, I'm a fan of the big picture (wide view) myself.

Regards, Ed.

[cowbell]

I hear horror stories about Ruby coatings, what is the story with Amber coatings?

[FLO]

I hear horror stories about Ruby coatings, what is the story with Amber coatings?

Red or 'Ruby' coatings are to be avoided but I am less sure about amber colour coating. I don't know the binocular but it probably has a single optical coating which can reduce the light loss (reflected off a glass surface) from around 4-5% to only 1.5-2%. To be truly effective all the air-to-glass surfaces would need to be coated. By comparison multiple lens coatings can reduce light loss due to reflection to only around 0.2 to 0.5% per air-to-glass surface.

Generally if you can see only one colour on the lens surface it is mono-coated whereas if you see multiple colours (usually shades of purple, green, violet and blue, depending on the angle of the light) then it is multicoated. 'Fully multicoated' is the gold standard because it means (we hope) all air-to-glass surfaces have multiple coatings. 

In daylight they give nice sharp views without any noticeable distortion at the edges.

I tried them out tonight first on the Moon and the view was sharp to the edge as far as I could see.

There was some CA (orange) just on the lower edge.

Sounds good

HTH, 

Steve 

[avtaram]

Thanks for all your replies.

I must say I am really enjoying these widefield views, never realised what I was missing.

Avtar