Quote:
Originally Posted by Wavytone
John - 60mm in fast scopes ? Oh really !?
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Wavy,
At no point in time did I make any comment about using any of these eyepieces other than the 32mm in a fast telescope. I have been around long enough to know that a sub F6 scope will create too large an exit pupil for any of these eyepieces other than the 32mm. You may be able to use the 45mm in an F6 scope but it won't gain you anything that you can't do with a 35mm or 41mm Panoptic.
Quote:
Originally Posted by Wavytone
The 32mm maybe but the 60mm is only suitable for f/10 or longer focal ratios - and that means SCT, mak or refractors; not newtonians.
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That comment is inaccurate. The field curvature of a catadioptic telescope is determined by the focal length of its primary mirror, not the overall F-ratio of the system. An F10 SCT will usually have a primary mirror with an F-Ratio of F2 to F2.5. For instance a Celestron C11 has an F2 Primary mirror with a focal length of 22" and it can exhibit significant field curvature with many eyepieces. That's why you use a field flattener with a SCT when imaging. Consequently these eyepieces may work well in an F10 refractor and not work well in an F10 SCT. You would need to try them on an individual telescope basis, not make a general speculative comment based solely on F-Ratio.
Quote:
Originally Posted by Wavytone
And 60mm suggests big scopes - 50cm or more.
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That comment is also inaccurate. Are you trying to tell me the 60mm wouldn't work well in the 15"/F12 (38cm) D & G refractor I have used on a couple of occasions, or the 6"/F12 D & G Refractor I have also used on a few occasions? Of course it would also work exceptionally well in the few remaining 4"/F15 (10cm) Unitron refractors still floating around.
Cheers,
John B