Eyepieces for 6" to 10" Dobsonians with 1,200mm Focal Lengths
Advice
TeleVue.com: Advice Article List > Eyepieces for 6" to 10" Dobsonians with 1,200mm Focal Lengths
Albert Nagler
CEO, Tele Vue Optics

Tele Vue eyepieces are ideal for maximizing the performance of 6", 8", and 10" Dobsonian telescopes with 2" focusers. The fast focal ratios of these telescopes place an extra burden on eyepiece performance. Because all Tele Vue eyepieces are designed for excellent sharpness over wide fields when used with fast telescopes, you'll get the most spectacular "spacewalk" viewing experiences using Ethos, Nagler, Delos and Panoptic eyepieces. If you must wear glasses to correct astigmatism and know the astigmatism value, it's best to call Tele Vue for specific advice. For a full explanation on how to choose eyepieces and an eyepiece calculator, you can check out Choosing Eyepieces.

Our 100° Ethos and 82° Naglers, in particular, will not only give you the widest, sharpest images, but very long viewing times as objects traverse the field. You won't have to constantly shift the scope to place the image in the "sweet spot," and of course, the whole "spacewalk" view is your "sweet spot."

I believe you only need three or four eyepieces to cover the full range, from low-power, wide true field, to high-power for planetary viewing. Since many 6", 8", and 10" models all have the same focal lengths (1,200-mm), the magnifications and field sizes will be the same for each eyepiece recommended (I assume you have a 2" focuser):

    Power Field
1. Low Power, Wide Field Either 35mm Panoptic
or 31mm Nagler Type 5
or 21mm Ethos
34x
39x
57x
1.85°
2.00°
1.73°
2. Low Medium Power Either 18.2 DeLite
or 17.3mm Delos
or 17mm Ethos
66x
69x
71x
0.91°
1.01°
1.41°
3. Medium Power Either 15mm DeLite
or 14mm Delos
or 13mm Ethos
or 13mm Nagler Type 6
or 13mm DeLite
80x
86x
92x
92x
92x
0.76°
0.83°
1.06°
0.84°
0.66°
4. Medium High Power Either 8mm Ethos
or 8mm Delos
or 7mm Nagler Type 6
or 7mm DeLite
150x
150x
171x
171x
0.66°
0.47°
0.46°
0.36°
5. High Power Either 6mm Ethos
or 6mm Delos
or 5mm Nagler Type 6
or 5mm Delite
or 4.7mm Ethos SX
or 4.5mm Delos
200x
200x
240x
240x
255x
267x
0.50°
0.36°
0.33°
0.25°
0.43°
0.27°
6. Alternative
 "Spacewalk Supreme"
 Ethos-only set
21mm Ethos
13mm Ethos
8mm Ethos
6mm Ethos
57x
92x
150x
200x
1.73°
1.06°
0.66°
0.50°

Note: using a Paracorr to eliminate the mirror's coma, will increase the power, and decrease the field of each eyepiece by 15%.

The above selection should give you great experiences for most viewing situations, although both a little more field and a little more power are possible using a total of four or more eyepiece choices. Also, if your scope is f/5 or faster, consider Paracorr coma corrector to get the full field sharpness your eyepieces can deliver.

For best eyepiece recommendations, call us at 845-469-4551 (9 a.m. — 5 p.m. ET Monday — Friday) to discuss integrating new eyepieces with your existing collection of eyepieces and scopes, budget requirements, and eyeglass / eyesight implications.

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