I never noticed this before ?
Posted 02 April 2013 - 06:45 PM
I noticed some thing interesting tonight. It happened while wearing my reading glasses in the dark.
I'd had just adjusted my binocular eyepieces, and forgot I was wearing glasses. When I brought the binoculars up to my eyes, the binos bumped the glasses up higher up on my nose. A moment later, I suddenly noticed I could instantly make out patterns of the Constellations. Only the brightest stars in the sky seemed to remain, as my reading glasses had defocused all of them.
If you wear glasses for reading, and, or are learning the night sky, try this for fun, it might even be helpful ? ? ?
Posted 02 April 2013 - 10:09 PM
Posted 03 April 2013 - 02:36 AM
Posted 03 April 2013 - 08:11 AM
Posted 03 April 2013 - 09:01 AM
Posted 03 April 2013 - 10:09 AM
Interesting- do you mean it was an afterimage that you saw, kinda like after looking at a bright light and closing your eyes..but you did this with stars?
Think of it this way: by looking at the sky with reading glasses, all of those point sources were defocused as if they were converted to nebulae with an angular dimension of perhaps a couple of arc minutes.
Because the surface brightness of each of the stars was now much lower than it was when visible as a point, the dim stars disappeared into the background leaving only the brighter stars still visible.