Ostara Plossl HR 20mm (1.25″) Eyepiece

The Ostara HR range of Plossl eyepieces provide excellent value for money with high optical and build quality. Fully coated to reduce reflections with standard astro 1.25″ fitting (suitable for the majority of astronomical scopes and some spotting scopes – ask if unsure).

Available in 10 sizes (4mm, 5mm, 6.5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 40mm and 12.5mm with illuminated cross hair).

Supplied in plastic cases for protection/storage.

Plossl eyepieces provide a wide field of view and are therefore ideal for a wide range of observational applications such as planetary and deep sky viewing.

What Magnification is this Eyepiece?
The magnification produced by an eyepiece depends on the optical system it is used in. In a standard astronomical telescope the magnification is found by dividing the focal length of the main tube by that of the eyepiece. For example, a 1000mm scope tube used with a 10mm eyepiece gives 1000/10 = 100x magnification. Used with a 5mm eyepiece gives 1000/5 = 200x.