The 5 mm BST ED eyepiece is the perfect eyepiece for large and medium magnifications. It is structurally constructed of six lenses in four groups, including two ED elements (low dispersion). Thanks to this, it allows for high contrast, excellent fidelity of color reproduction and extremely low levels of astigmatism and distortion, even in a short focal length telescope. In telescopes with long focal lengths, it allows you to obtain magnification close to or equal to the maximum. For example, in a 200 mm (8 ") f / 10 catadioptrophy telescope we get a magnification of 400x, equal to the maximum useful magnification of such a telescope.Moreover, the maximum useful magnification is used in very good conditions of the atmosphere stability ( seeing ).
In addition, the eyepiece is characterized by a 13 mm offset of the eye-relief , which is an outstanding result for the eyepiece with such a short focal length. In combination with the retractable eyecup, the eyepiece is also suitable for people wearing prescription goggles.
An own field of view equal to 60 ° allows for easier finding and keeping the observed object in view.
These glasses are known as StarGuider ED, BST ED and Paradigm Dual ED. Read the review on CloudyNights.com
| • Focal length: || 5 mm |
| • Field of view: || 60 |
| • Distance of the exit pupil: || 13 mm |
| • Diameter of binding: || 1.25 inches |
| • Anti-reflective layers: || FMC |
| • Number of optical elements || 6 lenses in 4 groups, including 2 of ED glass |
| • Weight: || 205 g |