Getting ready to silver
Have one of the 3 current 25" mirror projects ready to silver. This one being f5.295 in its uncoated state tested well under the night sky. Focus snap on moon and stars is good. Doesn't seem to have any noticeable astigmatism.
The only downside of such a long focal length is the height of eyepiece above the ground, (144"[12'] with dob on transport trolly). This puts a 6' observers feet over 6' off the ground when scope pointed at the zenith [vertical]. Ok up to a little over 45deg in altitude. Currently using a ladder may have to invest in a height adjustable platform.
Ronchi image (some air currents affects present). Second picture: getting ready to slide secondary cage (UTA) onto the 3m x 76mm strut poles. I have 3 sets of struts to suit the 3 different focal length 25" mirrors currently being worked on. Dob family in right picture,(14"f5.1, 8"f6, 25"f5.3).
Last edited by sopticals; 08-08-2015 at 06:54 PM.
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