磨镜高手请进啊。小弟遇到问题啦在线等啊！！

acseyang · 文章由 **acseyang** » 週二 07 2月, 2012 10:16

250/780卡式主镜
img068---抛光4h后的状态
img101;img103---采用宽W磨程进行修改后的状态

Chanlunlun · 文章由 **Chanlunlun** » 週三 08 2月, 2012 08:44

Hyperbola, no big deal !

acseyang · 文章由 **acseyang** » 週三 08 2月, 2012 18:12

actually i want make a parabolic mirror and i cant make different between Paraboloid and Hyperbola .because i want make a classical Cassegrainian telescope,its need
a parabolic optics.how can i correct the mirror to Paraboloid?

Chanlunlun · 文章由 **Chanlunlun** » 週五 10 2月, 2012 08:53

acseyang 寫:actually i want make a parabolic mirror and i cant make different between Paraboloid and Hyperbola .because i want make a classical Cassegrainian telescope,its need
a parabolic optics.how can i correct the mirror to Paraboloid?

Dear Mr/Miss Yang,

You need a precision Foucalt zonal test, best with computer aided analysis software, to determine the profile of the mirror. At f/3 one is required to accomplish very high accuracy in zonal readings.

Why stick to Cassegrain? If you really want to make one, make a Dall Kirkham. Spherical secondary and Ellipsoid primary are much more easier to make.

Best regards
Chan Yuk Lun

acseyang · 文章由 **acseyang** » 週一 13 2月, 2012 21:42

thank you very much .At first i dot know about DK too much.now i am follow your advice.And the primary mirror is close to Ellipsoid it will be easy to correct it.

香港天文論壇