[Stonius (Markus)]

Has anyone tried this?

I had a go at the ball-bearing artificial star the other night without success because 1) the reflection in the ball bearing was not bright enough to stand out and 2) minimum focus on the telescope would not allow focusing at that distance. I know you don't want focus for a star test, but you do want close to focus - this is nowhere near.

So I could venture into the driveway which has about a 70m clear run, but only a short window of full sun, or I could go to the park.

The main problem for me is not being able to achieve focus on anything that close. It would be good to know the minimum distance at which my scope will focus on an object. Apparently the formula for minimum focus for a simple lens system is 1/u + 1/v = 1/f.

u= distance from the subject to the lens
v = distance from the lens to the image
f = focal length

So I have a newtonian. I figure I can substitute 'mirror' for 'lens'. But is the focal length referring to the focal length of the scope or the eyepiece? and again is the image distance the focal length of the scope, or the eye relief of the eyepiece?

It's an 8" f/6 (1200mm), BTW.

***since the reflection of the sun is going to be way brighter than any star and still in essence, still looking at the sun do I need to treat this with the same safety precautions as with solar observing?****

Thanks for any geniuses who know the answer :-)