Tele Vue 21mm Ethos 2" Eyepiece

This is a wonderful eyepiece - no doubt. Optically close to perfect, this line of eyepieces allows you to similarly frame a DSO like a cluster or a galaxy at 2X the magnification that you'd get using a Plossl i.e. to frame a DSO the same way with a Plossl as this eyepiece, you'd have to use a 42mm Plossl. In the Ethos, the object would appear 2X as large. With sufficient aperture, you increase your chances of actually seeing the same DSO because even though the DSO is 4X fainter as compared to the 41mm Plossl, contrast is unchanged and at the large angle subtended by the object, your eye might succeed in detecting the object even if its undetectable with the 41mm Plossl in the same telescope. Look into the material presented in Roger Clark's Visual Astronomy of the Night Sky for a more detailed explanation of what I'm saying here...Specific to this eyepiece is the gargantuan weight of ~ 2.2 lbs!! Make sure that your focuser is able to handle the weight. You may have to upgrade focusers to prevent the eyepiece from slipping when focusing at targets close to the horizon.A second point to consider is the utility of this eyepiece. In my f/5.9 8" dob, I get a true FOV of 1.75 degrees! This means that this eyepiece is great for rich-field work, but perhaps a little too wide to appreciate smaller objects. For example, the ring nebula at 0.064 degrees is very small indeed in this monster! Consider pairing this eyepiece with a few shorter focal length eyepieces - a full set of the 13mm, 8mm, and 6mm Ethos complement this eyepiece nicely!

This eyepiece has a large field of view for the magnification it provides. I can fit the Perseus "Double Cluster" inside the same field of view in an 18" F4.5 Dobsonian. It offers reasonable magnification with incredible optical quality. Stars are dots to the edge of the field when I use a TeleVue ParaCorr. 21mm allows for great views when seeing isn't quite perfect. I plan to buy a 13mm Ethos for nights that will allow a bit more power. Globulars and planets especially love it.

Truly the best quality eye piece available bar none.

The gold standard of eyepieces. I used this in my 12" LX200 GPS and WOW! The views are MUCH greater than I got with the standard 26mm Meade 4000 series eyepiece that was my workhorse.

Stunning.

The best long focal length mass produced eyepiece ever made. Totally worth money spent.

I've had lots of wide field eyepieces, but this one would rank as the single best EP I've ever owned. The views of Andromeda through this revealed very clearly another spiral arm that I hadn't seen before visually. The Veil with an NPB filter was stunning in my 18.5". The optical precision, even at f/3.5, is astounding. And yes, this is very pricey, but if you're in this hobby for the long term, this EP won't be getting any cheaper anytime soon!