Telescope Reviews: Binoculars gather more light than telescopes?

DISCLAIMER: I am about to SAY more than I KNOW.

Mathematically, what Stephen and EdZ say about binocular summation is true. However, this is in an arena in which that which is perfectly true has several shades of gray, based on a number of variables.

As opto-geeks, we like our world to be wrapped up nicely and tied with a bow—that bow being made of mathematics and repeatability. On the surface, it would seem that stereopsis provides a 1.4 times increase in image brightness over that available through monocular vision. Some people even believe that the brain utilizes the mathematical light grasp of BOTH objective lens. This is not true. If it were, when placing your hand over one eye, your view would dim by 50%. Obviously, this has never happened with any test subject. Thus, in light of empirical data, both the 1.4 and 2.0 figures provided by mathematics go down in flames.

Now then, we KNOW the EdZ, Stephen T and many of those they quote are quite bright and have done their homework. SO, why is this lamb not lying down with the lion?

Because of matters that don’t relate to mathematics, but rather physiology . . . Unmathematical, unreliable and unrepeatable results pop up in testing based on PERCEPTION! Man, what a lousy thing to have to hang science on. From the mid-70’s to the mid-90’s millions of dollars in research were spent at some of our more prestigious universities to prove that little boys and little girls are—with the exception of a few body parts—the same. And, when the millions of dollars and 20 years were exhausted, what did they find? Little boys and little girls are different! What a concept. I would have told them that for a pizza and a Coke.

So it is with physiology. We are all different, and the strength of our abilities to perceive varies not only from individual to individual by within each of us as we are affected by alcohol, caffeine, fatigue, errors in collimation, Seidel aberrations and other variables.

For astronomy, does stereo vision make dim stars brighter, or does it make background “noise” diminish? If the later is the case, stereo vision would increase our ability to PERCEIVE the dim star without the star growing in the kind of brightness that would register in a photometer.

Those who would like to read more about binocular summation and probability summation should checkout the following website:

http://arapaho.nsuok.edu/~salmonto/VSIII_2006/Lecture10.pdf

Cheers,

Bill

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William J. Cook, Chief Opticalman, USNR-Ret.
Founding Editor, Amateur Telescope Making Journal
20-year vet. of Captain's Nautical Supplies, Optics Dept. Mgr.
Optics Machanic, WG11-3306, Ft. Lewis, Tacoma,WA
Yata, Yata, Yata . . .