Hi friends, sorry if i am posting my topic in wrong section.
Two weeks back i purchased SW EQ6 PRO mount and ES ED100mm APO refractor. I want to use it for visual as well as for AP. I have Canon 1300D DSLR.
My city is full of light pollution and sky looks orange almost all the time. Due to this reason i am looking for light pollution filter for visual as well as for AP use. Yesterday while searching on amazon i found the following LP filter :
1. Orion 5657 2-Inch UltraBlock Narrowband Eyepiece Filter
2. Celestron 93624 Narrowband Oxygen III 2 Filter
As i have no idea which one is best so i need your advice in choosing LP filter. You all are expertise in this field, your help is much appreciated.
For visual and AP, a narrowband filter that transmits the H-ß line and both O-III lines in the spectrum will work.
These go by names like:
TeleVue BandMate II Nebustar
Thousand Oaks LP-2
Since you'll use it for imaging as well as visual, you want the filter to pass red wavelengths. I've starred the ones that do.
These filters work on emission nebulae like Hydrogen gas clouds, planetary nebulae, supernova remnants, and Wolf-Rayet excitation nebulae.
They do not work on other nebulae, like reflection nebulae or dark nebulae, or on galaxies, star clusters, etc.
Broader filters, called CLS filters or Broadband filters, or LPR filters, simply won't work for you in the severe light pollution you have.
The O-III filter you mention is a photographic filter and is too narrow for most visual use. You won't even see an image in the eyepiece because
the field will be too dark and you won't completely dark adapt in that environment.
Your best bet (my night sky is so bright it's actually light blue most of the time, here in L.A.) is to transport yourself and the scope to darker skies.
Depending on the LP environment, you may not have to travel far. I'm in one of the brightest LP zones there is, and I only have to travel 85 miles to get to fairly dark skies.
You may be able to go much less distance and encounter dark skies.
Get in touch with the local astronomy club and find out where they go for star parties. Chances are likely it's not that far.
For viewing at home:
Bright star clusters
and, with a narrowband filter:
large bright nebulae like M42
the brighter planetary nebulae.
And leave galaxies, most nebulae, most star clusters, comets, and the Milky Way to your dark site viewing.
Edited by Starman1, 21 February 2019 - 11:05 PM.