Televue 21mm Ethos Eyepiece
Tele Vue has just announced their newest Ethos, the 21mm, but pricing has yet to be announced. Due to many requests from our customers, OPT has decided to allow pre-orders of this item. We believe the price will come in at about the same price as the 17mm, since they both have dedicated 2" barrels, but we won't know for certain until Tele Vue announces the price. Until then, OPT will take orders with zero down so that you can get in line. Once the price is announced, we will contact you to confirm the price and see if you would like to stay on the wait list. Those who say yes will be charged a 10% deposit to finalize their pre-order, and of course those who say no will simply be dropped from the wait list. Deliveries are expected to begin in December, 2009.By the way, the reason the price is shown at $1 instead of zero is because credit card authorization cannot take place with a zero balance. This allows you to enter your credit card information so that we can charge the deposit once the price is announced, or the balance due once your 21mm Ethos is ready to ship. You WILL NOT be charged the $1...even though that amount will show on your electronically generated invoice. The amount is for authorization only. If you prefer, of course, you can always choose the "check or money order" option for payment, and then provide credit card information to our internet sales department once the price has been announced. If you have any questions, feel free to email our internet sales department or call toll free at 1-800-483-6287.
Here is what Tele Vue has to say about their new 21mm Ethos:
Maximize your "spacewalk" experience with the 21mm Ethos. Transform your passage through the Milky Way with the 21mm’s nexus of contrast, power and field. Larger deep sky objects and rich star fields are its natural playground. Looking on-axis your field-of-vision is filled with 100º of stars, however wherever you chose to concentrate your attention you’ll see sharpness and richer contrast.
The optical performance of the 21mm is the work of Ethos lead designer Paul Dellachaiae, who achieved a level of optical aberration correction right in line with his other Ethos designs. Contrast and transmission have been maximized using the same advanced coating techniques and further aided by the internal mechanical design techniques used in all Tele Vue eyepieces.
Extending the Ethos focal length range to 21mm while maintaining the original performance goals of the rest of the series brings the eyepiece up against the mechanical limits of the 2” barrel and focus constraints. The 21mm provides the maximum true field of view, has no significant vignetting at the edge of the field, and is parfocal with the 31mm Nagler Type 5.
The 21mm focal length completes the logical set of 21mm/13mm/8mm and nicely juxtaposes the 17mm/10mm/6mm combination. Each step within these two sets approaches a 3X field area gain. The 21mm’s effective field stop diameter is 36.2mm, bringing its true field close to the 35mm Panoptic (38.7mm Field Stop diameter). Its true field is also larger than the 26mm Nagler with its 35mm effective field stop diameter. In an f/4 Dobsonian, the exit pupil is just 5.25mm using the 21mm Ethos instead of 8.75mm with a 35mm Panoptic, or 6.5mm with a 26mm Nagler.
Like all Tele Vue eyepieces, every 21mm Ethos goes through our optical and cosmetic quality control procedure in Chester, NY and should your eyepiece ever need service we can do everything from replacing a dented barrel to replacing a scratched eyelens.
Since all Ethos models accept Dioptrx, you now also have the “final frontier” – the ability to compensate for your own eyesight astigmatism with a superb multi-coated lens providing your exact correction, rotation orientation and centration over the eyepiece. This is the culmination of our quest to not only bring you observing experiences “…even better than you imagined,” but a 30-year recognition of being “tops in the field.”
Tele Vue 21mm Ethos Specifications...
- Effective Field Stop Dia.: 36.2mm
.jpg)
