3
$\begingroup$

I currently own a telescope, I'm an amateur astronomer and currently just trying to view the moon. I own the Celestron PowerSeeker 70AZ.

Link for information on the telescope: http://www.celestron.com/browse-shop/astronomy/telescopes/powerseeker-70az-telescope

The problem: I can't view the moon! All I see is a big ball of white, and since I'm new I thought I could get some advice for eyepieces: mine being a regular 20mm eyepiece. I don't use a barlow lens, mine broke.

Thanks! If you want any more specifications, just ask. I'm just looking for help! Thanks!

$\endgroup$
  • 3
    $\begingroup$ A big fuzzy ball of white? It sounds like you haven't focused the image. If that's the case, there should be a focusing knob somewhere on the telescope, you should see the image shift in or further out of focus as you turn it - just turn it until it's nice and crisp. $\endgroup$ – Mitch Goshorn May 3 '15 at 4:02
  • $\begingroup$ I do use the knob, and it doesn't really do anything. It is fuzzy. $\endgroup$ – PhilTheLawyer May 3 '15 at 4:07
  • 1
    $\begingroup$ Now I see what I've done. I don't have a moon filter! You'd think these would come with it! Thanks, I'm looking forward to getting one. $\endgroup$ – PhilTheLawyer May 3 '15 at 15:29
  • 2
    $\begingroup$ Don't bother with the Moon filter - if you use your telescope (and your eyes) correctly, it's a useless expense. See my reply below. $\endgroup$ – Florin Andrei Jun 26 '15 at 0:56
  • 1
    $\begingroup$ Do you wear glasses? Did you remove your glasses to view through the scope? $\endgroup$ – LDC3 Jun 26 '15 at 1:08
2
$\begingroup$

Your telescope is not focused (most likely), or is having some major collimation issues (less likely).

Try and move the eyepiece back and forth a little. Go through the whole range of the focuser. You must catch the primary focal plane in order for the image to become clear.

If that doesn't work, pull the eyepiece out a few mm and try to move through the whole range again.

If that doesn't work, try a different eyepiece.


The "advice" regarding the Moon filter is bogus. Be careful regarding what you hear on the Internet. The eye is certainly capable of adapting to various levels of brightness. Even with very large telescopes, the Moon filter is useless. All it does is reduce the brightness and contrast - the former is no big deal, but the latter is a major loss. You can never have enough contrast in a telescope.

When the Moon is visible, there's no point in going through deep dark adaptation anyway, because the "faint fuzzies" are obscured by Moon's glare. When I watch the Moon, I do it from a fully illumined backyard, or even on the street under the street lights. In fact, this is the best way to observe this object - no filters, but have some ambient light around you. Your eyes will function at optimal parameters.

Deep dark adaptation is only needed when observing faint nebulae and galaxies. But such objects can be observed in good conditions only when the Moon is below horizon.

Let me make it clear: a filter, any filter, will not fix the problem you're having, because it does not address the root cause.

Beware of most cases when the advice you receive is "use a filter". In 99% of cases, it's bogus. Many people own filters, but only a very small fraction know how to use them. In the vast, vast majority of cases you don't need any filters. Please steer clear of this superstition. It's a fad that vendors are more than happy to feed, because it makes them money.

There are legitimate ways to use filters (in the rare cases when they're justified), but that would be the subject of a different discussion - those rare cases are related to certain techniques of increasing the apparent contrast in the image. A neutral density filter (a.k.a. "moon filter") always decreases apparent contrast.

In this hobby, like in most other hobbies, a lot of people fixate on purchasing all sorts of accessories (in this case: filters), hoping to get extra performance, when all they need to do in reality is learn how to use the device / machine / etc (in this case: telescope) correctly. I see this tendency in all my other hobbies. It's unfortunate, and a huge money sink.

Save the money and use it instead towards purchasing a better telescope, or better eyepieces, or a good sky atlas, or an observing chair, etc.

$\endgroup$
  • $\begingroup$ Have you never looked at the moon through a telescope which has no moon filter and is not stopped down to a tiny fraction of its normal aperture? It is not a pleasant experience. $\endgroup$ – Wayfaring Stranger Jun 26 '15 at 7:41
  • $\begingroup$ I find it pleasant in a 130mm reflector with a 25mm or 9mm eyepiece. Bright, certainly, but not painfully so. $\endgroup$ – Russell Borogove Jul 2 '15 at 0:28
  • $\begingroup$ Jeez! I never accepted this! I just recently got a notification for it., sorry! Haha! $\endgroup$ – PhilTheLawyer Jan 1 '18 at 21:47
2
$\begingroup$

You've put in the moon filter, right? The moon is awfully bright without it. In any case, take the scope out in the daytime, and try focusing on distant objects; the tree at the end of the block, or the radio tower on top of the hill at the edge of town. A scope is easier to learn how to use when you can see what you're doing.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.