Do Home Built Observatories Cut Out Light Pollution?

[sabana]

The skies darken especially when viewing towards the Zenith. So can one assume that if Light from street lamps etc is blocked by an observatory wall from hitting the primary mirror etc then the sky will indeed be darker. There still would be some light pollution but it would be reduced. Or is it negligible?

[steppenwolf]

Observatories certainly work for 'local' light pollution, especially a dome type where you are viewing through a small aperture but, of course, they sadly have no effect on more distant pollution that pervades the whole sky.

[pete_l]

I don't think LP works like that.

When viewing things through a telescope, the biggest problem is not direct light shining into our eyes (or into the telescope). It's light transmitted upwards into the atmosphere which is then reflected off the water droplets, dust and all the other pollutants. This light mixes with the light from astronomical objects and interferes with (and blots out) them and adds artificial colours.

Having said that, when you look at the night sky with a naked-eye then what you can see is limited firstly by how dark-adapted your eyes are and secondarily by the amount of back-scattered light pollution. In this case, the direct light hitting your eyes from artificail lights does make a big difference. That's the reason that in all but the worst cases we can't see the yellow/orange hue of scattered LP, since our eyes don't get sufficiently sensitive because of all the direct lights shining into them.

[ismangil]

Anything you can do to cut extra light hitting your eye and the secondary mirror (more crucial than primary) will increase contrast, which is important for our visual perception.

[Merlin66]

The observatory (I have a small run off roof version) gives some immediate shielding from neighbours lights, is very convenient - leaving the scope/ mount all set up etc but unfortunately doesn't do ANYTHING to remove the local sky glow or light pollution around me. Would be great if it did!!