Kasai Trading 3x50 Constellation Wide Field Binoculars with 17° True Field of View
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An Immersive Observing Experience
The Kasai Trading 3x50 binocular is modern version of a Galilean ‘opera glass’ that’s been optimized for astronomical observation. These binoculars deliver up to a 17-degree field of view, allowing you to take in entire constellations in a single field. They help you see about 2.4 magnitudes fainter than is possible with your unaided eyes, which helps make it seem like you’re looking at the night sky with ‘super vision’. That’s also nearly a full magnitude fainter than the Kasai WideBino28 2.3x40 binoculars. The effect on visual observing is remarkable, especially when using these binoculars in dark sky to explore the star clusters and bright and dark nebulae of the Milky Way. Japanese amateur astronomers have used these modern Galilean binoculars since the early 1990s, and they’re finally available in North America.
Optical Design
Classical and inexpensive Galilean opera glasses and telescopes typically have a very small field of view. These Kasai binoculars deliver a much wider field using very fast objective lenses while managing the lens aberrations with additional optical elements to achieve flat fields from edge-to-edge with minimized aberrations. You enjoy pinpoint star images within full field of view. Every surface of the lens element is broadband multi-coated to enhance the transmission, and all the inner walls are thoroughly threaded and blackened to eliminate stray light.
Mechanical Features & Accessories
The body of the Kasai 3x50 binoculars is made almost entirely of metal. The compact body spans about 128mm and weighs just 285g. Each eyepiece focuses individually. Front and rear dustcovers are standard, and the binoculars include a neckstrap and a soft carrying case with a shoulder strap and a belt loop.
Specifications:
- Clear Aperture: 50mm
- Power: 3.0x
- Field of View: 17-degree
- Max. Dimensions: 128mm x 56mm x 56mm
- Weight: 255g
- Interpupillary Distance: 57mm - 73mm
- Diopter Range to focus infinity: > -6 diopter
- Focusing Mechanism: IF
- Standard Accessories: Front Dustcovers, Handstrap, Soft Carrying Case
- No rear end caps are included but we include a couple of Agena's yellow end caps at no extra charge
NOTICE (1): Galilean telescope system has no eye-relief. The best way to see the widest field of view is to "press" your eyes as close as possible to the eyepieces. When wearing eyeglasses, the field of view may be reduced. With very strong eyeglass prescriptions with stronger than -6 diopter, it may not be possible to 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 eye pupil diameters of the observer. The full 17 degrees field of view can be obtained when the pupils are opened maximum (usually 7mm). In brighter observing conditions or older observers, a smaller exit pupil will result in a reduced true field of view.
Other Information
- Country of Manufacture: China
An Immersive Observing Experience
The Kasai Trading 3x50 binocular is modern version of a Galilean ‘opera glass’ that’s been optimized for astronomical observation. These binoculars deliver up to a 17-degree field of view, allowing you to take in entire constellations in a single field. They help you see about 2.4 magnitudes fainter than is possible with your unaided eyes, which helps make it seem like you’re looking at the night sky with ‘super vision’. That’s also nearly a full magnitude fainter than the Kasai WideBino28 2.3x40 binoculars. The effect on visual observing is remarkable, especially when using these binoculars in dark sky to explore the star clusters and bright and dark nebulae of the Milky Way. Japanese amateur astronomers have used these modern Galilean binoculars since the early 1990s, and they’re finally available in North America.
Optical Design
Classical and inexpensive Galilean opera glasses and telescopes typically have a very small field of view. These Kasai binoculars deliver a much wider field using very fast objective lenses while managing the lens aberrations with additional optical elements to achieve flat fields from edge-to-edge with minimized aberrations. You enjoy pinpoint star images within full field of view. Every surface of the lens element is broadband multi-coated to enhance the transmission, and all the inner walls are thoroughly threaded and blackened to eliminate stray light.
Mechanical Features & Accessories
The body of the Kasai 3x50 binoculars is made almost entirely of metal. The compact body spans about 128mm and weighs just 285g. Each eyepiece focuses individually. Front and rear dustcovers are standard, and the binoculars include a neckstrap and a soft carrying case with a shoulder strap and a belt loop.
Specifications:
- Clear Aperture: 50mm
- Power: 3.0x
- Field of View: 17-degree
- Max. Dimensions: 128mm x 56mm x 56mm
- Weight: 255g
- Interpupillary Distance: 57mm - 73mm
- Diopter Range to focus infinity: > -6 diopter
- Focusing Mechanism: IF
- Standard Accessories: Front Dustcovers, Handstrap, Soft Carrying Case
- No rear end caps are included but we include a couple of Agena's yellow end caps at no extra charge
NOTICE (1): Galilean telescope system has no eye-relief. The best way to see the widest field of view is to "press" your eyes as close as possible to the eyepieces. When wearing eyeglasses, the field of view may be reduced. With very strong eyeglass prescriptions with stronger than -6 diopter, it may not be possible to 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 eye pupil diameters of the observer. The full 17 degrees field of view can be obtained when the pupils are opened maximum (usually 7mm). In brighter observing conditions or older observers, a smaller exit pupil will result in a reduced true field of view.
| Manufacturer | Kasai Trading Co. |
|---|---|
| Objective Lens Diameter | 50mm |
| Magnification | 3x |
| Field of View (Angular) | 17° |
| Coatings | Fully Multi-Coated Optics |
| Case | Yes |
| Neckstrap | No |
| Objective Lens Cover | Yes |
| Ocular Lens Cover | Yes |
| Inter-Pupillary Distance | 57mm - 73mm |
| Dimensions | 128mm x 56mm x 56mm |
| Weight | 0.62 lb (285g) |
An Immersive Observing Experience
The Kasai Trading 3x50 binocular is modern version of a Galilean ‘opera glass’ that’s been optimized for astronomical observation. These binoculars deliver up to a 17-degree field of view, allowing you to take in entire constellations in a single field. They help you see about 2.4 magnitudes fainter than is possible with your unaided eyes, which helps make it seem like you’re looking at the night sky with ‘super vision’. That’s also nearly a full magnitude fainter than the Kasai WideBino28 2.3x40 binoculars. The effect on visual observing is remarkable, especially when using these binoculars in dark sky to explore the star clusters and bright and dark nebulae of the Milky Way. Japanese amateur astronomers have used these modern Galilean binoculars since the early 1990s, and they’re finally available in North America.
Optical Design
Classical and inexpensive Galilean opera glasses and telescopes typically have a very small field of view. These Kasai binoculars deliver a much wider field using very fast objective lenses while managing the lens aberrations with additional optical elements to achieve flat fields from edge-to-edge with minimized aberrations. You enjoy pinpoint star images within full field of view. Every surface of the lens element is broadband multi-coated to enhance the transmission, and all the inner walls are thoroughly threaded and blackened to eliminate stray light.
Mechanical Features & Accessories
The body of the Kasai 3x50 binoculars is made almost entirely of metal. The compact body spans about 128mm and weighs just 285g. Each eyepiece focuses individually. Front and rear dustcovers are standard, and the binoculars include a neckstrap and a soft carrying case with a shoulder strap and a belt loop.
Specifications:
- Clear Aperture: 50mm
- Power: 3.0x
- Field of View: 17-degree
- Max. Dimensions: 128mm x 56mm x 56mm
- Weight: 255g
- Interpupillary Distance: 57mm - 73mm
- Diopter Range to focus infinity: > -6 diopter
- Focusing Mechanism: IF
- Standard Accessories: Front Dustcovers, Handstrap, Soft Carrying Case
- No rear end caps are included but we include a couple of Agena's yellow end caps at no extra charge
NOTICE (1): Galilean telescope system has no eye-relief. The best way to see the widest field of view is to "press" your eyes as close as possible to the eyepieces. When wearing eyeglasses, the field of view may be reduced. With very strong eyeglass prescriptions with stronger than -6 diopter, it may not be possible to 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 eye pupil diameters of the observer. The full 17 degrees field of view can be obtained when the pupils are opened maximum (usually 7mm). In brighter observing conditions or older observers, a smaller exit pupil will result in a reduced true field of view.
Other Information
- Country of Manufacture: China
| Manufacturer | Kasai Trading Co. |
|---|---|
| Objective Lens Diameter | 50mm |
| Magnification | 3x |
| Field of View (Angular) | 17° |
| Coatings | Fully Multi-Coated Optics |
| Case | Yes |
| Neckstrap | No |
| Objective Lens Cover | Yes |
| Ocular Lens Cover | Yes |
| Inter-Pupillary Distance | 57mm - 73mm |
| Dimensions | 128mm x 56mm x 56mm |
| Weight | 0.62 lb (285g) |
Kasai Trading 3x50 Constellation Wide Field Binoculars with 17° True Field of View