Light Pollution Filters - having i been doing it wrong all this time ?

[Northernlight]

Hi All,

After reading some posts on on topics about filters I'm beginning to wonder if i've been using my old Astronomic CLS CCD filter wrong for years.  So my astronomic CLS CCD is always in my imaging train whether i'm imaging Narrowband or LRGB and i'm thinking - do i really need to use it when i'm doing narrowbnd ?

So just wondering if using the LPS filter in conjunction with my narrowband filters has actually been hampering me ?  yes i can understand for the LRGB, bit do i really need to use it when doing narrowband ?

Have i been doing it wrong or is it ok to use LP filters with narrowband filters ?

Rich.

 

[vlaiv]

2 minutes ago, Northernlight said:

do i really need to use it when i'm doing narrowbnd ?

No, not needed at all.

3 minutes ago, Northernlight said:

So just wondering if using the LPS filter in conjunction with my narrowband filters has actually been hampering me ?  yes i can understand for the LRGB, bit do i really need to use it when doing narrowband ?

It is doing small amount of "damage" to your imaging. Not much. Such filters usually have something like >95% transmission, so you are loosing about 5% of light or similar (some have 98% transmission while others 90(ish)% - depends on actual filter).

Any optical surface will introduce some aberrations and it depends on quality of surfaces just how much it will be. Some filters cause star bloat or not perfectly round stars - but most are ok and have minimal impact.

5 minutes ago, Northernlight said:

Have i been doing it wrong or is it ok to use LP filters with narrowband filters ?

Depends - if you are happy to accept small light loss and don't have any significant image degradation (and I'm guessing not since you use it with LRGB anyway), then this can outweigh hassle of removing filter from imaging train every time you switch between LRGB and NB.

If it's not too much work to remove it - then why not as it is not needed.