The longest focal length in the 52° Series with the longest eye relief, the 40mm is also the only 2.0-inch O.D. eyepiece in this series. Explore Scientific now has three 40mm eyepieces in its collection, the other two are the 40mm 62° Series, and the 40mm 68° Series. At this focal length, this eyepiece is generally reserved for deep sky observers who challenge themselves to observe near the faintest observable limit of their telescopes. The huge true field of view is perfect for deep sky objects like the Andromeda Galaxy, the Rosette Nebula, as well as large star clusters, and comets.
