TeleVue 3.7mm ETHOS-SX Eyepiece
Manufacturer : TeleVue
Part Number : ETH-03.7
Al Nagler eagerly pushed Ethos designer Paul Dellechiaie to extend the new 3.7mm focal length
to reach 110°, the same field as the LEM Simulator optics Al designed 45-years ago to train NASA
astronauts for lunar landings.
Tele Vue 3.7mm Ethos-SX (Simulator eXperience)
Worlds 1st Astronomical Eyepiece with 110° Apparent Field
With 110°, the Ethos-SX has 21% more AFOV area than the 100° Ethos design. This permits a nice 62% power increase from a 6mm Ethos, while retaining 68% of its TFOV. The 3.7mm actually has more TFOV than our 8mm Plössl, 6mm Radian, and 5mm Nagler Type-6!
In 1.25" mode, it is parfocal with the wide range of 1.25" Tele Vue Plössls, Panoptics, Radians, Naglers, Nagler Zooms, and 6mm and 8mm Ethos eyepieces. The screw-on 2" adapter (included) is designed to make it parfocal with 13mm and 10mm Ethos when they are used in their 2" modes.
|Focal Length (mm)
|Barrel Size (in.)
||2" & 1¼"
|Apparent Field of View (deg.)
|Eye Relief (mm)
|Weight (lb / oz)
||1.10 / 17.6
|Field Stop (mm)