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. You can check out the wavelength blocking information on their website and see that it has many of the same pass bands of your typical light pollution filter. While I have not used this particular filter personally, I have talked to several people using them who say they are quite good visually but not that great when imaging.
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.
A relative newcomer, and the cheapest of the bunch, is the Optolong Moon & Skyglow filter. If you look at the wavelengths on the chart for this one you will see it is a virtual exact copy of the one for Baader which makes me think this is a cheap knockoff, as its name would suggest.
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.
Hopefully this little assortment will let you select the best light pollution filter that is right for you and will help you view or image all the amazing things in the night sky.
I hope you enjoyed this article on the best light pollution filter!