Are Night Sky Filters Worth Buying?

Astrophotography is a tricky business, even if you happen to live in the Namib desert. However, if you don't live in such a remote location, you'll likely have struggled with light pollution. In recent years, we have seen a number of filters designed to help with this problem. But do they work?

There are worse places for me to live as somebody interested in astrophotography, but not by a great deal. I live a stone's throw from London and to the north of me, Cambridge. Between those two cities are a while host of towns of varying sizes and all the light pollution that goes with that. I have spent time combing over light pollution maps to find the darkest places near me and have driven several hours to get to the pockets of darkness fairly near me in England. Nevertheless, unless I drive to Scotland, the skies aren't great for astrophotography, particularly if you want to capture the Milky Way as I do.

Light pollution is irritating for several reasons, but two are particularly troublesome. The first is the orange glow, which makes your images look ugly to my eye, but are easily fixed in post (and even in-camera in some circumstances) with white balance tweaks. The second is far more damning, however: a lack of contrast. For the stars and celestial bodies to be easily visible in your photographs, you need contrast, which is to say, a dark sky for the stars to "pop". A night sky filter is said to help resolve both of these issues. While it undoubtedly fixes the first, the second is open to some debate.

Do you use dark sky filters? Do you think they're worth it?

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4 Comments

Michael Krueger's picture

Don't use a filter, never considered it where I live. Look at North Dakota light pollution and you'll understand why. If you don't know much about North Dakota it's about 75% of the size of the UK while having a population of 675,000 people. Majority of the state is farm land and little towns of only a few hundred people. We actually have dozens, probably hundreds of ghost towns because many of the small farm communities founded in the 1800s were abandoned in the 1900s as people moved into the few larger cities we have.

I didn't even know light pollution was a thing 20 years ago when I was a kid, I had a night sky full of stars, I remember seeing a meteor shower in plain site not knowing what it was. I remember asking my dad why the sky was green when I saw the northern lights. As an ignorant kid I assumed everyone could see the night sky. Lol

W Mitty's picture

Nice reminiscence. I grew up assuming that everyone could only see a few stars in the night sky. I grew up in the east where it was nigh impossible to get away from the light. When I was 20 years old, I drove across country in August and one night, at about two in the morning as I was just crossing over into Montana, I saw the Perseid meteor shower for the first time. I had no idea what it was and couldn't believe how big and dramatic the sky was. I stopped and watched for several hours. Made me fall in love with the western skies.

Jeremy Lusk's picture

Used one for the first time a few weeks ago and it definitely made a difference. Even in a dark sky community, you’re often photographing in the direction of towns of cities way in the distance that will creep into the shot. They’re probably less helpful the more we move away from incandescent lights towards LED, but still a better starting point for images that you’ll end up doing some pretty heavy post processing on.

Nathan Wong's picture

Yes, they're worth it 100% I live smack dab in the middle of a highly populated city and and the sky would be red if I didn't use a filter. Instead of red I get a blue-ish tint instead. I've shot the Orion nebula, M42 (who hasn't?), the Lagoon Nebula, M8, and the Trifid Nebula, M20. Each one I absolutely couldn't have captured without a filter. If you're trying to get deep sky objects and not just the run of the mill Milky Way shot that any smartphone can capture nowadays, you need a filter. If you live in absolutely dark areas you'll still need a filter that's sensitive in certain frequencies in order to capture details.