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