4 different telescopes need questions answered under the topics of chromatic aberration, resolving power. etc?

Question

I know the D, Fo, Fe, LGP, and Mp
how I can i tell which telescope sufferes from Chromatic aberrtion?
How can i tell which has the worst resolving power?
how do i get the ratio of how much greater the light gathering power of the biggest is to the smallest?
and finally how would i sovle this questions what is th ehighest magnifing power you could get with these telescopes and eyepeices ( any of the telescopes with any of the eye peices.

yes you are correct on D, Fo, and Fe, LGP is light gathering power, and MP is magnifing power

Answer 1

Only refracting telescopes suffer from any noticeable chromatic aberration. These are the "typical" looking telescope with lenses in front and the focusser at the back.

Resolving power is proportional to aperture. More aperture = more resolving power.

The square of the ratio of the diameters (or the ratio of the squares, works either way) gives you the relative light gathering power between two telescopes.

The most power a telescope usually can handle is 50 times the aperture in inches, though the atmosphere won't usually hold up to more than 300 to 400 power.

Answer 2

I assume D is the diameter of the objective, Fo is the focal length of the objective, Fe is the focal length of the eyepiece, and LGP is light gathering power. I have no idea what Mp is. Maybe it has something to do with chromatic aberration, which the other things do not.

Magnification is Fo/Fe

Resolving power is inversely related to D. There are several formulas you can use, but one is Dawe's limit, which is 4.56/D. Where D is in inches and the resolution you calculate in in arc-seconds. (3,600 arc-seconds = 1 degree). So the smallest D has the worst resolving power and the biggest D is best.

LGP is the area of the objective, which would be Pi*D*D/2 (area of a circle). So twice as much D means 4 times the LGP.

In theory you can get unlimited magnification from any telescope with a very small Fe plus an extra lens called a Barlow. But more than about 50 power for every inch of D is useless because the image gets dim and the size exceeds the resolving power of the objective.

Reflectors have no chromatic aberration. Refractors have different amounts. Clever design and lots of lenses can reduce but not entirely eliminate it. Maybe your mysterious Mp is some chromatic parameter, like dispersion or whatever.

Answer 3

Unfortunately, it's very hard to compare telescopes "by the numbers." There are many other factors which are as important or more so, such as design of the system (achromat vs. apochromat vs. Newtonian vs. catadioptric) and the reputation of the manufacturer (quality control issues, polish of the objective). Things like Fe are irrelevant, since any eyepiece can be used in any scope, LGP and Mp are irrelevant since they are functions of D. You'll get a better comparison if you just list the candidate telescopes.

Incidentally, Yahoo Answers is a terrible place to look for technical answers like this, since very few people here have much practical knowledge of telescopes. You'll do much better asking in one of the Yahoo Groups devoted to telescopes, such as the one in the source below.