Spectroheliograph focus???
Just a hint to new SHG users.....
How do you know if your slit gap is at the focus of the telescope?
Normal method is to check the top/ bottom edges of the solar spectrum being recorded. When in focus, they should appear tight and crisp.
A quick way to get you close....
Use a finder to look through the objective and check that the slit gap appears in clean focus.
Helps during initial set-up.
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