Still not sure if I need a light pollution filter

[smr]

Hi all,

I've wondered whether I should be buying a decent light pollution filter for sometime now and am unsure whether one would help me.

If I am able to take 3-5 minute exposures at the correct ISO setting for my Camera (purportedly ISO 200-400 for the Canon 80D) with the histogram data in APT showing 20-30 percent of the way across, do a need an LP filter?

I have Bortle 5, 19.57 mag skies.

Obviously if I had a bright orange background then I would buy one without hesitating but the background isn't washed out or so, but it does look a bit brown from the subs the other night on M33.

 

I don't think the sky conditions were great, maybe something to do with the altitude, might have been high cloud which was hard to see and the transparency was a bit poor, compared to this Eastern Veil shot, ISO 200, 180 second image, but towards the Zenith on a different night though when conditions looked better...

 

 

But then targets coming up in the winter like the HH & Flame, Rosette etc. are lower down where there's more of that sky fog so the images will probably resemble more of the first with that brown murkyness.

But anyway, do I need a light pollution filter like the IDAS D2? Would it help SNR even if I can get rid of gradients with gradient xterminator - one inverse selection and medium / medium and the levels are balanced and any background gradients are removed.

Where I image from doesn't have any direct source of lights really but there's that obvious sort of sky wash which is LED'ish looking, hence wondering if I should buy the IDAS D2.... but if it doesn't improve the SNR also then I don't see much point spending £200 on one.

Edited October 24, 2019 by smr

[ebdons]

Hi, it depends what LP you have usually in winter the sky near me is better and sometimes I don't need a specific filter, the lower down the object I use a IDAS NB1 for nebs etc and NGS1 for skyglow even at a dark site. you might have to get some 2nd hand and see what filter is best as I found I needed to get some others first to see if I could improve my imaging and exp length, a lot to learn but location and light type is important to get it right. why not try the CLS or UHC first. tony