With its exceptional apparent angle of view, the Tele Vue Ethos 13mm Ultra Wide-Angle Eyepiece offers views with high contrast and excellent on-axis sharpness; and virtually zero astigmatism or field curvature across its expansive 100° field of view.
Combining a hyper-wide apparent angle of view with its medium focal length, this Ethos delivers moderate magnification for most general observation needs on near and deep-sky objects alike — while still offering an expansive and immersive observational experience. This eyepiece is parfocal with the 10mm Ethos, thus requiring little or no refocusing when changing between the two, and it also accepts astigmatism-correcting DIOPTRX diopters to further improve the view.
A unique design characteristic of the Ethos allows it to be used with the smaller, more common-sized 1.25" drawtubes and accessories; and a simple screw-on installation of the included adapter converts it for use in larger 2" versions. This provides users with an easy and convenient way to expand its functionality and versatility, without limiting its use or relying on clumsy eyepiece holder reducer adapters.