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Old 06-06-2018, 08:36 PM
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Astrofriend (Lars)
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Join Date: Aug 2017
Location: Stockholm, Sweden
Posts: 188
Hi Jameson,
What parametrar do you use in my calculation? I used 100 mm opening and f/7 but that gives other figures.

Be aware that my answers are +/- 45.9 microns, you have to double that to compare with some of the others. 91.8 microns in focus length. I'm not aware of CFZ, but when I did my equations I compared with other calculation and it lined up good. But there are for sure a lot of different way to do this calculation.

https://en.wikipedia.org/wiki/Depth_of_focus

If you do visual or have a green/yellow filter you use 550 nm, if doing rgb photo and with good quality optic maybe better to use the blue (shortest) wavelength, about 400 nm. Mirror telescope or APO refractor.

/Lars
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