Aperture Ratio and Resoving Capacity

[abumuhannadh]

hi guys.

can someone explain how does aperture ratio affect the view?

and what is resolving capacity and how does it affect?

thank you

Abu Muhannadh

[gareththegeek]

Telescope Basics

This link is quite useful, it explains f ratio and resolving power.

HTH

[NGC 1502]

Hi, Aperture ratio :- is the telescopes focal length divided by its aperture ( a 1200mm focal length with a 200mm mirror is 1200/200 = F6 ) A lower F number like F4 will give lower magnification and wider field of view, F10 gives higher power & narrower FOV, if using the same eyepiece in both scopes.

Resolving capacity :- Theoretically, larger apertures give greater resolution, ie more planetary detail, split closer double stars, but there are several other factors, quality of instrument, collimation, state of atmosphere, skill of observer etc. Hope this helps, Ed.

[abumuhannadh]

thanks guys,

the links were very helpful.

i have another question,

here is a statement i found in a website describing a telescope they sell

" The giant planet Jupiter, just a bright star to the unaided eye, will, at around just 60x magnification, show the observer a larger image of Jupiter´s globe in the eyepiece than the full Moon appears to the unaided eye!"

i don't have a telescope yet, so i am not sure, but i doubt it can be as large as full moon to the naked eye at just 60x

what do you guys say?

[themos]

wikipedia says Jupiter varies from 29.8 to 50.1 arc-seconds. Even the smallest value is about half-an-arcminute. The full moon is about 30 arc-minutes so at 60x it would appear as big as the Moon.

[abumuhannadh]

that seems right

thanks for clarifying

[Peter Drew]

It's hard to believe the fact that at 60x in the telescope, Jupiter looks the same size as the full Moon. Until you look at the full Moon through an 1.25" fit non optical component, you will be just as amazed at how small the Moon looks!