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Old 12-10-2015, 02:37 PM
vapeinspace (R)
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Join Date: Oct 2015
Location: Australia
Posts: 13
Quote:
Originally Posted by julianh72 View Post
A 10 mm chrome ball bearing makes a great artificial star - put it out in the sun for daytime use (position it in the sun against a dark background), or put it down the far end of a dark hallway and shine a bright halogen light on it for indoor / night testing.

When you do the maths, the image of the sun or a halogen light on a 10 mm sphere at a distance of 20 metres or so is small enough to be a pinpoint for practical optical testing purposes.
Great. Thanks for the tip Julian, it's always good to have other options.

And for the maths too!

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