Question about telescope lenses?

Question

I own a celestron nexstar telescope. I really don't know much about space and basically got it just so I could peek at the stars. I own three lenses with which I can get an awesome view of the moon but cannot see any other planets sharply, with my most powerfull lense mars is still just a very bright star. So I was wondering if it is possible to get an even more magnifying lens which would allow me to see other planets more clearly. If you have any suggestions or links it would be greatly appreciated

So is there any way I can enlarge the resolving power? Thanks

Answer 1

Not really.

Enlargement is only part of the equation. What you need is more resolving power, not enlargement. If you made anything larger, it would be larger but fuzzier. The most important aspect of a telescope is the light gathering capability, that means the size (diameter) of the mirror.

Sorry if that sounds bad, but that is the way it is. Large telescope do not make things necessarily bigger first, but brighter and sharper. Once you have sharp and bright, then one can enlarge.


Increasing the resolving power means increasing the diameter of the telescope. You cannot upgrade a telescope, you have to replace the whole unit.

Answer 2

You didn't specify the model of the NexStar so I can't tell you which eyepiece to use specifically.

Every telescope has a highest practical magnification. This is the magnification you can use without exceeding the telescope's theoretical resolving ability. If you have the NexStar 60, you can't use more than 118x magnification. If you have the NexStar 130, then you can't use more than 256x magnification.

This assumes you are in outerspace though.

In reality you will probably have to use far less. But here's what you can do to get the best view of planets possible.

1. Choose a night that is very calm and clear and dry. No wind and no haze on the horizons.

2. Let the telescope and eyepieces sit out for at least an hour. The colder it is, the longer it needs to sit, unless it was stored in a place equally cold. This "cooling down" allows the telescope to reach equilibrium with the environment and is a VERY important step to follow to see the planets well.

3. Point your telescope at Jupiter.

4. Start with the lowest power eyepiece and work your way up to higher powers.

5. Even if the view isn't perfect, watch it for a while, it might clear up for a short moment allowing you to see the planet in great detail.

Mars can offer nice views but often has planet wide dust storms that obscure the surface.

Answer 3

You don't say what the aperture of your scope is. Nexstar makes some fine scopes and if the image is crisp and sharp, even though tiny, a 2x Barlow lens will magnify the power of any eyepiece by 2. You could also buy a lens with a smaller millimeter opening, thereby increasing your magnification. The thing to remember is, if the small image doesn't look sharp, the big image will be an even bigger blur. For astronomical observation, the aperature size (the front lens of the scope) is key. Most astronomers want a wide field of view. Mars' appearance will vary as its distance varies. It has a highly elliptical orbit which can vary from 60 million miles from earth to a little over 20 million miles from earth. Check it out again at its next closest approach. With a Nexstar I imagine you could resolve the polar caps.

Answer 4

Mars is still fairly far away and is not much to look at right now. Try Jupiter, or, early in the evening, Saturn. To see the maximum of detail on the planets, you need to focus very carefully. Also, if your telescope is a reflector, make sure it is collimated.

As far as which eyepiece to use, it sometimes happens that the atmosphere is too unsteady to take advantage of your maximum magnification. Start your observing at low power and then see how much magnification you can use without the planet getting fuzzy looking. As a general rule, you won't find any improvement with magnifications of more than 50x per inch of aperture (2x per mm).Watch for those brief moments when the air steadies and everything looks sharp.

Answer 5

Presently Mars is too far away to see more details with any amateur telescope. I would suggest you to look now - this week - at Venus and at Saturn. Venus should look like a waning crescent and at Saturn you should see the ring system. If you can see those two planets in the way I wrote, then everything with your telescope is ok.
A higher magnification is not always showing more details. The opposite can be true. You have less light and more wobbling with a higher magnification.
To calculate the best magnification as a rule of thumb just take the front opening of your telescope in mm - this will give you the best magnification factor. Max useful magnification is sometimes 20 to 30 percent higher.
To calculate your actual magnification divide the focal length of your telescope by the focal lengt of your interchangeable eyepiece.
P.S. I was looking at Venus and Saturn this evening with a magnification of 80x - it was great.

Answer 6

Why can't multiple images from multiple telescopes be combined to have greater resolution?

Answer 7

ask Starr !!
send her your question here .
she s an expert on telescope lenses!!

she helped me !

http://asktheastronomer.blogspot.com