BST Flat is a series of modern glasses in a cast 1.25 inches flat field from shore to shore. These are glasses with focal lengths of 8, 12, 16, 19 and 27 mm, with an AFOV field of view from 53 to 65 °, depending on the model.
Advantages flowing from the field's flatness
FLAT glasses do not require correcting the focus of the object during drift through the field of the eyepiece - this is a feature particularly valued by users of Dobson telescopes, for which the observation type "move - observe drifting objects - move objects" is typical ".
The 5-element optical construction with a field of view from 53 to 65 ° has been designed with great care. Glasses are paraphrone as part of a series, so they do not require (or require very little) fine-tuning the focus after changing from one focal point to another. The inside of the eyepiece is blackened with matte, the edges of the lenses are blackened in a similar way to minimize internal reflections and the resultant loss of contrast. All surfaces are covered with excellent anti-reflective layers for high transmission through the optical system.
The eyepiece body is made of aluminum, with an anodized black exterior. For a certain grip, there are rubber rings on the cover of the 8 mm focal length lens. The glasses are equipped with rotating eyecups with a rubber finish that is comfortable and comfortable in contact with the face.
Each eyepiece has a groove on the sleeve that prevents the eyepiece from falling out (the groove includes a press ring or a screw on the eyelash / extractor). In addition, each eyepiece is equipped with a standard filter thread.
| • Focal length: || 19 mm |
| • Field of view: || 65 ° |
| • Distance of the exit pupil: || 12 mm |
| • Diameter of binding: || 1.25 inches |
| • Anti-reflective layers: || MC |
| • Number of optical elements || 5 |
| • Height: || 60 mm |
| • Weight: || 115 g |