Binoscope vs. One Scope

Can anyone tell me how a binoscope compares to a single scope in terms of detail, lightgathering ability, viewing, etc. For example, is a binoscope made with two 4" refractors the equivalent of a 6" or an 8" refractor? Any guidelines will be appreciated, so thanks in advance.

Chuck

Hi Chuck,

A binoscope shows fainter objects and more detail than a single scope, but not for the reason you might think. There is no increase in lightgathering ability, as each eye still only sees light from one telescope. However what does happen is that the brain now recieves 2 images of the sky. One from each eye. The brain then compares the 2 images and rejects anything that is not in both images. Therefore a lot of the "noise" that is in the view is rejected, allowing more of the image to be viewed. I am not sure of how much you gain, but as a guess it would probably be a couple of inches. "Sky & Telescope" magaziene ran an article on the advantages of a binocular scope many years back, so it might be worth trying to track it down.

Hope this helps.

Maurice

Strictly in terms of light collectin AREA 2X 4 in refractors have combined aperture equivlalent to a Single 5.657" refractor. (you multiply by the square root of 2, ~ 1.4142). But since light from each of the two objectives reachs only one eye it is not clear if our brian received twice as much inforamtion.

For me personally, the difference of having binovision on DSOs and star clusters is quite dramatic! I can percive a lot more details with my 20X80mm binoculars than I can with my 80mmF5 refractor. You can try it yourself with a pair of 10X50 binos mounted on a tripod. Try capping and uncapping one of the objectives while keeping both eyes open. It seems the view is dimmer by at least 1/2 magnitude when one of the objectives of my 20X80 bino is covered.

Erik D