question about dob construction // secondary mirroPosted By John Biretta |
I think you just made a oversight somewhere. The distance from mirror surface to focuser does not depend on the diagonal size, at least for this program. It will depend on stuff like the focuser height, extra focus distance, tube thickness and tube diameter.
As you change the diagonal minor axis from 3.1 to 3.5, you should notice this value "0.xx" in inches right below the "Calc" button changing:
"100% Illuminated Diameter: 0.xx inch"
It should be about 0.4 inches larger for the 3.5 inch diagonal (assuming both values are larger than zero).
As you change the diagonal minor axis from 3.1 to 3.5, you should notice this value "0.xx" in inches right below the "Calc" button changing:
"100% Illuminated Diameter: 0.xx inch"
It should be about 0.4 inches larger for the 3.5 inch diagonal (assuming both values are larger than zero).