A Tele Vue 6mm Ethos in the Celestron C11 optical tube gives 467x, a 0.21 degree true field and a 0.6 mm exit pupil. The worked calculation and whether it sits in the useful range.

Updated 05 September 2026.

Eyepiece and telescope pairing

Tele Vue 6mm Ethos in the Celestron C11 optical tube: magnification and field

What the Tele Vue 6mm Ethos does in the Celestron C11 optical tube, worked from the published focal lengths and apparent field.

Field of view

ring = 0.21 degrees true
dot = 0.6 mm exit pupil

Computed optics

Magnification
467x2800 mm / 6 mm
True field
0.21 degrees100 deg / 467x
Exit pupil
0.6 mm280 mm / 467x
Max useful mag
660xpublished
Barrel match
1.25 in eyepiece in a 2 in focuser
Fits

Good fit. In the Celestron C11 optical tube the Tele Vue 6mm Ethos gives 467x with a 0.21 degree true field and a 0.6 mm exit pupil, inside the telescope's useful range.

Magnification is the telescope focal length divided by the eyepiece focal length: 2800 mm divided by 6 mm is 467x. The true field of view is the eyepiece's 100 degree apparent field divided by that magnification, 0.21 degrees.

The exit pupil, the width of the light beam leaving the eyepiece, is the aperture divided by the magnification, 280 mm over 467x, which is 0.6 mm. That makes this a high-power lunar, planetary and double-star setting.

The eyepiece to buy

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Related

Celestron C11 optical tube280 mm f/10
Tele Vue 6mm Ethos6 mm, 100 deg
Best eyepiece for the Celestron C11 optical tubeexit-pupil match

Questions and answers

Tele Vue 6mm Ethos in the Celestron C11 optical tube: magnification and field?

Good fit. In the Celestron C11 optical tube the Tele Vue 6mm Ethos gives 467x with a 0.21 degree true field and a 0.6 mm exit pupil, inside the telescope's useful range.