What Can An Astronomer Expect to See in a Light Polluted City with a Telescope? From a very light polluted city one can see the moon and planets perfectly in a telescope (basically almost identically to seeing them in the less light polluted skies). Bright star clusters are all pretty good, we just lose out on DSO (nebulae dimmer star clusters and double stars, etc). If you do want to see DSOs, make sure you go out when the moon is not out.

However if you are in the city, you can offset your unluckiness by heading once in a while into the country as it makes a world of difference!
However do make sure that you plant to go when the moon is not out (not near the full moon at least), that way you don't waste your trip like I once did!

Another way to bypass light pollution partially is by using light pollution filters however these will only help to see nebulae slightly better.

A final way to increase your viewing capabilities is astrophotography. One can easily capture objects that normally one would not see using long exposure astrophotography, however this requires some expensive pieces of equipment: adaptor, camera (digital SLR or CCD), and a very good mount to track sky objects over 30 seconds without trailing (or bumps - wind/shaking etc!).

Good read.

Nice information for newbies.

Very nice read.

Poor seeing? First, keep in mind that transparency and seeing are two different animals. Transparency is a measure of how clear the sky is. Seeing is a measure of how "steady" the sky is. You can have very clear skies and turbulent, unsteady views of the planets. You can also have very hazy skies and very steady, detailed views of the planets - a night of good seeing.

Aperture determines potential resolution, and larger telescopes are capable of seeing finer detail. This also means that seeing more often limits the capabilities of larger scopes. While a quality 4" telescope may be able to perform to its ability on many nights, a 10" telescope might be limited by the steadiness of the air.

You have to be careful because there are other issues that can impede the performance of larger instruments. Their optics have more mass and hold more heat, so it takes them longer to cool down. On nights of dropping temperatures large telescopes are often playing catch up. Active cooling methods can help.

In my experience here in the northeastern U.S., at least in the 3.5" to 10" range, a larger telescope always seems to hold some advantage for planetary viewing. With patience the larger always shows moments to minutes where it reveals more detail. In addition, when using the same magnifications, a larger instrument provides a larger exit pupil, reducing the effect of floaters, and provides better color rendition.

I did an experiment with my wife's 14.5" f/6 equatorial on several nights when Saturn and Jupiter were well placed, using it with a 6.5" off-axis mask and at full aperture. While I was certainly not seeing all the detail a 14.5" would be capable of showing at full aperture, the views were always better than they were with the off-axis mask. The mask went in the trash.