Orthoscopic eyepieces offer a particularly flat image field with uniform sharpness from the center to the edge. They are therefore particularly interesting for observing the moon, planets and - with a sun filter - the sun.
The eyepieces go to the renowned optician Dr. Masuyama , who developed many of the best Japanese eyepieces from the 1960s and 1970s. Dr. Among other things, Masuyama designed an eyepiece with a focal length of 100 mm, which was used for visual observation on the historic 60-inch telescope at the Mount Wilson Observatory in California. After almost 30 years, the legendary Masuyama eyepieces are back in production. They are manufactured by Ohi Optical using the latest glass and multilayer technology made in Japan!