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Ethos Focal Length Groups of Three

Started by jameskevin, 12/01/2023 03:21PM
Posted 12/01/2023 03:21PM Opening Post
Why are Tele Vue Ethos eyepieces often recommended in groups of three focal lengths:

21mm, 13mm and 8mm

or

17mm, 10 and 6 mm?
Posted 12/01/2023 10:39PM #1
Originally Posted by James Erwin
Why are Tele Vue Ethos eyepieces often recommended in groups of three focal lengths:

21mm, 13mm and 8mm

or

17mm, 10 and 6 mm?
Depends on your scope butĀ of the two groups I'd go with the 17, 10 and 6mm because the 21mm weighs a ton and may cause balance issues and the 10mm tests much better optically on the bench tests than the 13mm.