One of the main reasons it is so hard to see or image some objects in the night sky is light pollution. This is caused by all the street lights, signs, and other illuminations lighting up the particles and water vapor in the atmosphere. That’s why you need the best light pollution filter you can get. The problem is that it seems everyone is jumping on the light pollution filter bandwagon and that makes it hard to figure out what is the best choice for you. Lets see if this light pollution filter review helps.
What is a light pollution filter?
Light pollution filters are typically 1.25″ or 2″ round filters that screw into your telescope to reduce the effects of light pollution on your viewing or imaging. These can be screwed on to a camera adapter, eyepiece, or onto a diagonal. There are some which are designed to clip inside a DSLR but these are very specialized so they will not be covered in this article.
These filters are designed to block specific wavelengths of light. This is not to be confused with contrast boosting filters or filters that just block out a single whole range of light. If those filters qualified as a light pollution filter, so would a piece of glass spray painted black blocking all light.
An easy way to rule out cheap filters that claim to be the best light pollution filters but really are not is that any real filter will come with a chart showing what wavelengths of light are blocked, and which are not. In addition, this should have several sections where it is blocked and several sections where it is not.
If the manufacturer or reseller do not provide such a sheet, stay away! If the sheet they provide has one big ole blocked section, stay away! Before and after pictures will probably be faked or worse, they might images of a city at night or something like that and they actually look better. The city pictures are worse because I want a filter for looking at faint nebulae and galaxies, not downtown Los Angeles!
Some people ask, do light pollution filters work? Not just yes, but oh yes!
Recommended best light pollution filter
First on my list is the one I use virtually all the time, the Baader Moon & Skyglow filter. I tend to use this both visually and for imaging and have had fantastic results.
It is not only one of the best light pollution filters, but also helps remove the skyglow caused by the moon (reflected sunlight), and also increases contrast by boosting RGB at specific wavelengths. If there was only one filter made, this is the one I would prefer. This was the one of the first astrophotography filters for DSLR astrophotography I purchased, and it was worth every penny.
Of all the filters I have used, this was one of the best light pollution filter for dslr astrophotography I could find. It’s wavelengths matched my Nikon DSLR quite well. In fact, I have not used another filter that performed as well as this one as it produces improved image quality over every other filter I have tested.
Orion makes an excellent pair of filters in their Orion Skyglow line. The reason I mention pair here is that although there are two different sizes (1.25″ and 2″) just like the Baader filter above, there also is two different TYPES of Skyglow filters: visual and astrophotography. Be sure you get the right one!
The visual filter leaves a little more green in the image than the astrophotography version which makes sense. Your eye is more sensitive to green and most of the nebulae and galaxies have a green tint to them visually anyway, so this actually helps you see things. On the other side, no one wants greenish photographs so they correct that in the filter for astrophotography.
My experience shows they both work pretty well, although one of the imaging versions I tried had defective threads and had to be returned. I am not sure it worked any better or worse than the Baader so I would personally prefer one filter that rules them all, so to speak 🙂
That being said, this is one of the best light pollution filters.
The Thousand Oaks Broadband LP-125/LP1-48 filter is sometimes called a nebula filter, and it does indeed help you see nebulae. 
All of the Thousand Oaks optical products I have tested have been excellent so I would not hesitate to use one myself. My only reservation here is that, as the name suggests, this filter seems to be optimized for nebulae and I suspect that might limit its usefulness with other objects. This may mean it is actually better at nebulae than the other filters listed here too.
I have talked to a few people who have used these and they say that for the money, these are not that bad. If you need something to start with and can not afford a filter from the big boys then this might be something to start with. For the price, if it did half the job of the Baader filter, it would be a nice improvement.
I hope you enjoyed this article on the best light pollution filter!
I have found your astronomy reviews to be the most straightforward and most helpful in pretty much every equipment category. When researching a new topic (light pollution filters this time), I check your review FIRST and then subsequently read and balance all the others against it. I have spent literally hundreds and hundreds of hard-earned dollars based on your reviews and have yet to be disappointed. THANK YOU for making often-extremely-complex choices much easier.
Thank you also for recently adding Explore Scientific to your eyepiece reviews.
My only concern here for the light pollution filters is that for the first time that I can recall you are recommending products you have not actually tried (albeit for the lowest-end products). I (and I am sure many others) value your opinion enough to bank our wallets on it, and we want to hear what YOU say.
Thank you again, and carry on!
I live somewhere where I am constantly fighting light pollution so I jumped right to the good stuff in my purchases. I do need to go back and try some of the less expensive models now that I have something to compare them to. Thanks for reminding me of this.
Like so many people in 2020, I jumped on the astrophotography bandwagon and have been in a state of constant learning and wasting money. I’ve got a Sigma Zoom lens, it uses 95mm filters, I’m confused as to how I would use the Baader Moon and Skyglow filter ? Their website shows 2 inches as a maximum size and 95mm is closer to 3 3/4 inches.
Thank you !!
If you need a filter for a DSLR, mainly Canons, you can use a drop-in filter like this one https://amzn.to/3nN6FAd. Unfortunately the Baader I recommend is for attaching to a telescope and not a lens.