Originally posted by zeeblebotWhen you compare eyeball scopes, binoculars, and such, the standard binocular at 7X50 is 7 power and 50 mm diameter primary lens. That number is based on the size of the pupil which means the light coming out of the telescope or binocular closely matches the size of the opening in the pupil, I recall a # like 2.5 mm or such. So if you take a 50 mm lens and force it to be 14 power, the light is in a smaller cone and so the circle you see covers less of your visual field. Also, a rule of thumb is the max magnification is something like 2 times the diameter, so the max you can expect out of a 50 mm lens is about 100 power but with a 50 mm lens that means the image would be a pinprick size, like looking through a pinhole in a paper. So if you wanted 100 power and still have the full size image going through the pupil, it would have to be about 15 times larger than 50 mm (100/7=14.2) so 15 times 50 would be = to about a 20 inch (750 mm) sized primary lens. That makes a X100 image fill your pupils. So for a hubble, if you were using it like a pair of binoculars (which of course is impossible, being in orbit) a 2.4 meter (2400 mm primary/50=48) which is the # that you would multiply times the 7 power of the 7 50 standard which would make the power only about 350 times! That is only the power that would be useful for human eyes, but you could get 3500 power if you confined the light to a cone 1/10th the size of the full pupil opening. So my question I guess would be the technical issue of what is the effective size of the exit image in the longest range image, which is about 13 billion light years out. Using that # you could tell the effective power of magnification.
nice pics and article.
By Andrew Moseman
Published on: January 23, 2009
The 5 Most Powerful Telescopes, and 5 That Will Define the Future of Astronomy
2009 is the International Year of Astronomy, celebrating the 400th anniversary of Galileo turning a looking glass to the sky ...[text shortened]... iant Magellan T, Chile, construction to start in 2011
Thirty-Meter T, Chile or HI, in design.