best slit spacing and 3rd order spectrum for 400mm f/2 scope

[skyjak]

Hi Satoru, I would like to create a TriBahtinov-Bahtinov mask for a C8 (whose native focal length is 2000mm) with HyperStar, which produces an effective focal length of 400mm. By using your drawing app, the slits come out very thin (using a Bahtinov ratio of 100). But if I check "Use 3rd order spectrum", then the slits become quite wider. So my question is: what is the 3rd order spectrum? and should I use that option to draw the optimal TriBahtinov-Bahtinov mask for 400mm f/2 scope? Thank you! -Julio

[satakagi]

I have no idea too. I only feel empirically that a narrower slit will produce a clearer diffracted image. You might consider asking this question on cloudynights. Satoru 2022年3月20日(日) 3:14 skyjak ***@***.***>:

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Hi Satoru, I would like to create a TriBahtinov-Bahtinov mask for a C8 (whose native focal length is 2000mm) with HyperStar, which produces an effective focal length of 400mm. By using your drawing app, the slits come out very thin (using a Bahtinov ratio of 100). But if I check "Use 3rd order spectrum", then the slits become quite wider. So my question is: what is the 3rd order spectrum? and should I use that option to draw the optimal TriBahtinov-Bahtinov mask for 400mm f/2 scope? Thank you! -Julio — Reply to this email directly, view it on GitHub <#2>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABT2UENGB5CJNCBZJPNFYVLVAYKQNANCNFSM5REKSBBQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[skyjak]

Thank you Satoru. Yes, I found examples on Cloudynights of how the slit width affects the diffraction lines. Definitely better the thinner they are.

Regards,
Julio