figureing fast mirror for a 1.0x coma corrector
Posted 25 June 2013 - 03:35 PM
Posted 25 June 2013 - 05:55 PM
Have you considered an even faster primary to be used with the TV Parracor II?
What aperture are you considering? Up to moderate apertures it shouldn't be necessary to go as fast as f/3.5.
Posted 26 June 2013 - 09:45 PM
Posted 26 June 2013 - 10:03 PM
It is my understanding that this extender effect is necessary to correct for some spherical abberation that is introduced in the coma correction.
Can't say for sure, but it's more likely it's to allow (Paracorr) to fit in a standard focusing scope and still provide for EPs to reach focus downstream. It also makes it slightly easier on those EPs.
Posted 27 June 2013 - 01:28 PM