Originally Posted by kljucd1
So, this method doesn't cause any risk of damage to the equipment/user?
It's best done with a newtonian scope (because they are well ventilated and have less inside them that an be burned) and maybe even go to an old eyepiece just in case. I used to do it with my old 8" newt, and a 2-2.5" off axis objective mask to knock down the heat a bit.
You just don't want to get the focal point inside the EP while your focussing, or focussed on part of the insides of the scope while you're pointing it at the sun...
I used to focus on something as far away as possible, then fit the off axis mask, and place the tube cap over that. Then aim at the sun and use the shadow of the tube to get it aimed (it's pretty close when the tube shadow is circular
), and then remove the objective cap and fine tune the focus.