[Dennis]

Originally Posted by GeorgeC

Using the masks visually will cause some strange effects as your eye slightly changes its focus. All 3 spikes in a Bahtinov will move simultaneously, but it can look as if just the central spike is moving.
I have never tried looking through the telescope with a Carey mask in place - I will try this out when the sky is clear!

Hi George

Thanks for that and thank you for the very informative lessons on diffraction covered on your website!

Cheers

Dennis