Kasai Trading Astronomical observation binocular telescope “dedicated” StellaBino-50

Ships from Japan "Inverted image" binocular telescope for astronomical observation / no prism or erecting lens system Equipped with a high-precision 5cmF4 objective lens equivalent to that of an astronomical telescope / fully multi-coated with a transmittance of 99.5% Image quality is much sharper and brighter than regular binoculars φ31.7mm eyepiece replaceable / Free selection of magnification and field of view Left and right viewing axis adjustable by user / Ultra lightweight specification of 660g Effective diameter: 50mm Focal length: 200mm Aperture ratio: F4 maximum dimensions: 255mmx120mmx57mm Weight: 660g Focusing mechanism: IF compatible eye width: 58mm to 74mm Eyepiece standard: Rotating helicoid / φ31.7mm insertion (metal ring tightening type) Other specifications: With objective hood / With screw hole for attaching tripod adapter (with lid) / Equipped with an eccentric visual axis adjustment mechanism (dual tubes) Standard accessories: Front and rear caps, neck strap (Note: Eyepiece not included) An entirely new concept "inverted image" binocular telescope exclusively for astronomical observation that connects two 5cm F4 high-performance astronomical telescopes. With a simple structure that does not include prisms, you can obtain clear and sharp image quality that is on a whole other level compared to ordinary binoculars. Since the eyepiece is replaceable, you can freely select magnification and field of view. Filter work is also possible. Furthermore, since there is no field of view restriction due to a prism, the maximum field of view can be secured with a φ31.7mm eyepiece. It has a unique design that combines a binocular-like form that can be easily held and used with the basic functions and structure required of an astronomical telescope. The lightweight 660g casing ensures a comfortable grip while also having the same specifications as a full-fledged astronomical telescope. . This is truly a one-of-a-kind, revolutionary binocular telescope created just for astronomy enthusiasts. ＜Development concept＞ Binoculars were originally made for ground observation. Of course, it can also be used for astronomical objects, but it is only for diversion, and therefore it is an absolute requirement that it always be erect. However, in order to obtain this erect image, it is necessary to incorporate multiple prisms, which inevitably causes image quality deterioration and light loss. Furthermore, the field of view is limited by the size of the prism. For example, with standard 5cm binoculars, it is physically impossible to secure a field of view of 7° or more regardless of the magnification. (Of course, there are some models that incorporate giant prisms to achieve ultra-wide fields of view, but they are generally very heavy, large, and extremely expensive.) Furthermore, fixed magnification is also inconvenient. The eyepiece is also built into the housing, so attaching the filter is not easy. On the other hand, astronomical telescopes generally have an inverted image, and it is well known that this is done to maintain and maximize the performance of the objective mirror. In the first place, there are no clear ups and downs for celestial bodies (e.g. (If you go to the southern hemisphere, many constellations can be seen with north and south turned upside down), and many astronomy buffs are familiar with inverted images through the use of astronomical telescopes, so as long as you specialize in astronomical objects, the factor of ``upright images'' is not necessarily necessary. In fact, the benefits (sharpness, wide field of view, brightness, etc.) that can be obtained by abandoning this factor are far greater. On the other hand, the fact that the eyepiece can be replaced, the magnification can be easily changed, there is no field of view restriction, and filters can be attached freely is a major advantage, and is an essential factor for astronomical applications. With these points in mind, the idea behind the development of this camera was to create a pair of binoculars exclusively for astronomical objects that would have the functionality of an astronomical telescope while maintaining the convenience and operability of binoculars. After several years of conceptualization and numerous prototypes, we were finally able to produce and sell this machine. ＜Optical system＞ Equipped with a high-precision two-element achromat 5cmF4 objective lens designed and manufactured for astronomical telescopes. It is broadband fully multi-coated and has a high transmittance of over 99.5%. Although it has a short focal length, the imaging performance is very high, and 20~ Sharpness is easily maintained up to high magnification ranges of around 30x. Chromatic aberration is also well corrected and is kept to an almost unnoticeable level in the practical magnification range for stargazing. Coupled with the simple structure that does not use prisms, it provides clear and clear image quality that is on a whole other level compared to regular 5cm binoculars. ＜Eyepiece Specifications＞ The focusing mechanism uses a smooth rotating helicoid. The operability is the same as that of IF binoculars, so you won't feel any discomfort when focusing. The focusing stroke is 16mm and the maximum back focus is 8mm, ensuring infinity focus with almost any eyepiece. The 31.7mm eyepiece adapter uses a metal ring tightening type that emphasizes centering retention. In addition to easy eyepiece replacement, the eyepiece can always be fixed securely and accurately. ＜Case Specifications＞ Designed for hand-held use, we have adopted a unique design that combines a binocular-like form that fits comfortably in your hand with the basic functions and structure required of an astronomical telescope. An objective hood with a length of 50 mm is installed at the tip of the tube. It reliably blocks oblique light even when observing in bright surroundings. The inner surface of the hood and the inside of the cylinder are fully coated with low-reflection black. Further inside the cylinder The lens is equipped with a light-shielding baffle similar to that of regular astronomical refracting telescopes, which prevents internal reflections and greatly contributes to improving image contrast. Since the orthodox center-folding method is used to connect both tubes, it is possible to adjust the eye width with the same operation feeling as regular binoculars. Of course, there is also a screw hole for attaching a tripod adapter at the front of the center axis, so if you use the tripod adapter (sold separately), you can mount it on a photo tripod, etc. Holes for straps (included) are also provided on the left and right sides. ＜Eccentric Visual Axis Adjustment Mechanism＞ This product is always shipped with the visual axes of both tubes accurately adjusted, but as is the fate of binocular telescopes with interchangeable eyepieces, there are times when the visual axes cannot always be maintained perfectly during actual use. In particular, in the case of an eyepiece with a step in the barrel, there is a possibility that it will tilt slightly when worn, and in the case of a heavy eyepiece, the eyepiece itself may bend slightly, causing the visual axis to become slightly misaligned. In order to easily solve this problem on the user's side, this machine has a visual axis adjustment device placed between the main body of both cylinders and the A-piece adapter. This structure is generally called an "eccentric visual axis adjustment mechanism," and it has two slightly eccentric lenses. This is a method to adjust the viewing axis by connecting the rings and rotating both appropriately. Normally, this adjustment is located inside the objective lens cell, making it difficult for the user to adjust it, but this camera has two pairs of adjustment rings on the outside of the rear of the lens barrel, allowing the user to easily adjust it as necessary. (Note: The visual axes are precisely aligned before shipping, so there is no need for readjustment during normal use. Please use this function only when necessary.) ＜Overall Suitability＞ This is a one-of-a-kind, unique pair of binoculars created ``only'' for astronomy enthusiasts. Since the eyepiece can be replaced, magnification and field of view can be freely selected. Filter work is also possible. Of course, there are no field of view restrictions. Even with two eyepieces weighing around 100g each, the total weight is less than 1kg, making it easy to hold and use. The most important feature of this lens is that it has a simple structure that does not include prisms, allowing for extremely bright, clear, and sharp image quality. Please use both eyes to fully enjoy the sight of the stars and nebulae and star clusters that are right in front of you with the eye-catchingly clear image quality.