Light pollution filters

[shiladazz]

Hi,
 

I see a lot of debate on the use of filters and whether they are effective on cutting out some of the light pollution wavelengths. But all of that discussion is for astrophotography. My question is for visual observations only.

I observe most of the nights from my home which is inside a town and I can see upto magnitude 3 stars with naked eye. 
 

I have an 8 inch Dob. Do you think any type of filter can improve the viewing? For example if I want to see the M13 in Hercules, will a Filter help? 
 

best regards

[Ricochet]

An Astronomik CLS might show a tiny bit of improvement, any cheaper light pollution filters will definitely be a waste of money. If you can locate M13 as a faint patch of light then the best filter you can use from home is to increase the magnification, up to the point where the exit pupil is ~1mm. 

The best light pollution filter is to put your dob in the car and drive away from the light to a dark site, when/if possible. 

Edit: I should point out that the 1mm exit pupil limit advice is solely for open and globular clusters in which the stars can be resolved as points of light. For extended objects (eg galaxies) the limit is an exit pupil of ~2mm. For nebulae you can use UHC and OIII filters, which require even larger exit pupils and will probably only be of use on the brightest nebulae under your skies. 

Edited May 30, 2021 by Ricochet