Is the difference as great with telescopes as it is by naked eye?

Question

Comparing the "view" of the night sky from most street-light polluted urban settings, with the view one gets treated from a far off rural setting, is truly and wonderfully dramatic! Is there this much "difference" when one uses a small telescope -- instead of the naked eye ?

Answer 1

The view of the night sky in an urban area is reduced because of the ambient light  generated by the area itself.

In this situation a telescope will not improve the view because the lenses in the telescope are light gatherers... light amplifiers.

In a rural setting this ability to gather light significantly improves the look into the night sky... but remember, a telescope also narrows the view to whatever field of view is inherent to the telescope. There is no panoramic view with an amateur telescope.

Answer 2

I live with about as much light pollution as you can imagine.  Downtown Detroit, but across the street from a grocery store parking lot - complete with flood lights. I have a ten inch (254 mm) telescope.  For galaxies, my 60 mm spotting scope at a reasonably good dark sky site will outperform my 254 mm reflector at my house.  Most galaxies are not as bright as the sky, and there's not much you can do about it.

However, an Oxygen 3 filter brings me nebulae from my driveway, even if the nebula is sitting in the sky between flood lights.  This narrow band filter only sees light given off by a certain excitation of oxygen.  High pressure sodium lights don't emit here.  So my views of, say, the Eagle Nebula, are as good from my driveway in my 10 inch scope as they are from good dark sky sites.  Smaller scopes don't gather enough light to make the filter work.

From high light pollution sites, i can see stars, double stars, clusters and nebulae (with O3), but not much in the way of galaxies.

If you want to see meteor showers or the full Milky Way, or zodiacal light, there's nothing better than naked eye viewing under dark skies.

Answer 3

Yes.

The telescope has two (small) advantages:  with longer focal lengths and magnification, you can increase the contrast between a star and the background.

Also, if the light pollution comes primarily from the same type of light, you can get special filters to eliminate some of it.

For example, in my area, there are lots of low-pressure sodium streel lights.  They emit light in very few narrow bands (very specific colours).

Special filters can remove only those colours and leave the rest untrouched.  This lowers the "background" light from the atmosphere.  (If you are observing an object that happens to glow in these colours, then that object is also made fainter -- the filter does not guess if the light is from Earth or from space, it simply eliminates the specific wavebands).

But, in general, the effect is similar.  Any light pollution that makes the sky milky instead of black, will also affect what we see in telescopes.  It is particularly annoying when trying to view extended objets like a nebula.

Answer 4

Faint extended objects (galaxies and nebulae) are hurt worst by light pollution. Urban sky glow is brighter than most galaxies, so they simply become invisible. Stars are point sources, so with enough magnification, you can still see them through the glow. But since there's a limit to how much magnification you can practically use, the number of faint stars you'll see through the telescope is effectively reduced also.  But for the most part, it's amazing how many stars you *can* see in urban skies with a telescope.

Answer 5

a dark country sky will make any telesscope work better.

even binoculars work better. the view through a little telesscope is amazing. the view through a big telesscope is breathtaking.

i have family who live out in the country with observatory-class skies. there are so many stars it can be hard to find the constellations.

Answer 6

The difference between the unaided eye and a reflector, say, of aperture 8" or more is equally dramatic. Even a 4" reflector holds surprises, but at 8" and up, you will be blown away.

Now, if you go to a dark sky site, look up, and say to yourself "That's all there is?", then a telescope won't offer much emotionally. :)

HTH

Charles