WideBino28 optical designWideBino28 is a peculiar star-gazing instrument yielding 28-degree field of view with your both eyes. While most constellations can be captured within a field, 1 or 2 magnitude darker stars can be detected - you must feel as if your eyes are suddenly "doped". Since early 90's, this unique device has been enthusiastically loved by huge number of Japanese astronomers. Now it's your turn to experience this marvelous view.
WideBino28 was entirely renewed in April 2016 - the optical quality, usability and versatility are all dramatically improved. For more details, click here.

<Optical Design>
Basically the field of view of Galilean opera glasses is very small. The only way to widen it is to use extremely fast (f/2 or faster) objective lenses, but normal achromat doublet lenses of such fast f-ratio show strong aberrations and it's practically impossible to be used for visual observations. The optical design of WideBino28 is epoch-making as adopting 2-group 2-element meniscus objective lenses and 1-group 2-element cylindrical eyepieces, achieving edge-to-edge very flat widefield with very little aberrations. You can enjoy pinpoint star images within full field of view. Every surface of the lens element is broadband multi-coated to enhance the transmission rate, and all the inner walls are thoroughly threaded and blackened to eliminate the stray lights.
<Mechanical Features & Accessories>
Most parts of Max. 123mm width / 255g weight compact body are made of metal. Individual focusing. Front & rear dustcovers are standard. Comes with a neckstrap and a soft carrying case with a shoulder strap and a belt loop.
<General Aptitude>
The extremely wide 28-degree field of view brings overwhelming feeling of liberation, having a great aptitude for night sky observations. It can capture one constellation within a field of view, with 1 or 2 magnitude darker stars emerged - it must be the best and the only one device that can do a "feat" for the observes to see the whole figure of a constellation with scattered deep-sky objects in it. Especially, the beautiful images when seeing the Milky Way are beyond expression. Once you see it, you must become addicted. Please do have such a peculiar experience as "constellations come closer to you".
2-way carrying case

2-way carrying case
Clear Aperture 40mm
Power 2.3x
Field of View 28-degree
Max. Dimensions 123mmx40mmx50mm
Weight 255g
Interpupillary Distance 52mm - 73mm
Diopter Range to focus infinity > -6 diopter
Focusing Mechanism IF
Standard Accessores Front & Rear Dustcovers
Neckstrap, Soft Carrying Case
NOTICE (1) : Galilean telescope system has no eye-relief. The best way to see the widest field of view is to "press" your eyes close to the eye lenses. Therefore, it's essential to see through WideBino28 with your naked eyes. (Very strongly shortsighted eyes, as - 6 or less diopter, can't reach the infinity focus. In such cases wearing contact lenses is recommended.)

NOTICE (2) : The field of view of Galilean telescope system varies by the pupil diameters of the observer. 28-degree can be obtained when the pupils are opened maximum (usually 7mm.)
*Dear European Customers
You can purchase WideBino28 from our European exclusive distributors "AOK Swiss" & "Telescop-Service".

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A pair of adapter ring set to accept M48 filters (for 2" eyepieces.) Try to enjoy diffuse nebulae near Milky way with UHC filters, or challenge to detect faint and wide-spread nebulae like Bernard's Loop or IC1396 with OIII or H-beta filters. Just remove the rings in front of the objective lenses, and screw those adapters - then M48 filters can be attached. M48 Filter Adapters (pair) for WideBino28
WideBino28 w/M48 Filter Adapters + Nebula Filters
WideBino28 + M48 Filter Adapter +M48 Nebula Filters (not included)
<NOTICE>: The thread sizes of the former WideBino28 (supplied until April 2016) and the latest model are different.
When ordering M48 Filter Adapters, please indicate which model you have owned. (We have 2 types for both in stock.)
Kasai Trading Co., Ltd.
5-19-33, Kami-Meguro, Meguro-Ku, Tokyo 153-0051, JAPAN