If you live in a light-polluted area but still want to observe and take near-perfect images of the night sky, then a light pollution filter can make all the difference.
Known as the “abomination to Skygazers” light is something that you really do want to limit if you are hoping to see the finest objects in space. This is particularly true if you are getting into Astrophotography, whereby better pictures are the result of optimizing the finer details.
Whether you live in a highly light polluted area (like a city) or even one that appears to be darker (town/ neighborhood), you will be sure to benefit from a light pollution filter when taking pictures of the sky.
The truth is that due to modern day environments, street lighting, signs, buildings, housing and other illuminations simply envelope a preventative dome of light pollution above us. The result is that entire constellations are concealed from view, and the ability to observe the Milky Way becomes impossible.
Thankfully, due to technological advancements, light pollution filters can reduce and eradicate local light pollution and give you back the ability to observe some of the most interesting deep sky objects, like Nebulae. It is these filters that enable us to pick up certain wavelengths of light unique to objects of the sky and therefore give us clear views despite unfavorable conditions here on Earth.
Remember: the ability for us to observe objects in the sky entirely depend on how much light we can pick up through our apparatus (Telescope, Binoculars etc). Light Pollution Filters therefore swing the balance back into favor of those objects in the sky.
The difficulty is, that knowing what Light Pollution Filter is best can be quite difficult. There are several different brands and spec to understand. There are also other things to consider like what you want to observe, your telescope and your budget.
This buying guide will help you identify the Best Light Pollution Filter For Astrophotography, for you.
At the end, you will know exactly what to look for and what filter is going to be best. If you wanted to get a quick overview of the filters covered in this guide:
Now before we take a look at the filters, let’s us first discuss what they actually and what they enable us to achieve:
What Are Light Pollution Filters (What Do They Do?)
Light pollution filters are glass optical filters that have been designed with dozens of layers of closely integrated coatings. They reduce the effects of certain wavelengths of lighting (like those produced in our environment) to reveal deep-sky objects that can be hidden due to high light pollution.
They will not be able to completely block out light pollution, and they will never be better than when you observe with completely dark skies, but when you choose the right filters for your own interests and telescope, they will prove to be an unbelievable aid when taking photos of great detail on celestial objects.
Light pollution filters generally are created in the following sizes: 1.25″ or 2″. They are easy to attach to telescopes, usually they just screw in. There are various places where you can screw a filter in: onto your camera adapter, telescope eyepiece, or onto a diagonal. Then, there are some that clip directly inside DSLRs but these tend to be immensely specialized and probably beyond the scope of this article.
When looking for a light-pollution filter it is important not to be confused with contrast boosting filters or those that only block out a limited range of light (or an entire range for that matter). The best and most recommended way to identify a cheap filter is to look for, or look at, the charts that come with it and that are cited. This will provide you with the wavelengths of light that the filter was design to block (and also which ones that it cannot block).
So, it is important to always use respected manufacturers that provide such material. If they do or cannot – its usually a red flag! Another thing to avoid on these charts are any entire blocks that are completely eliminated through the filter. Finally, be cognizant of manufacturers and the images they provide for proof of the filter in use. Some may fake the before and after pictures whilst others may use the filter to take terrestrial (on the Earth) pictures. Consider that you want to use the filter to observe Planets, Nebulae and Galaxies – not cities! The cheaper filters are normally sourced from China and are of inferior quality.
Nonetheless – with these considerations in mind, the right light filter can be transformative, especially to those of you who have not used them before.
With the above in mind, I will now walk you through the best filters from the best and most respected brands:
Best Light Pollution Filter For Astrophotography
So here are the filters; please note: all filters are available in both 1.25″ (31.75mm) and 2″ (50.8mm). The only difference is size, the same features still apply. You can access each size on Amazon via the table at the top of this buyers guide.
There are two types of filters included in this list: Bandpass and Narrowband. They both help pass frequencies within a certain range (deep sky objects) and reject frequencies outside of that range (light pollution). Whilst Bandpasses are the most common and are brilliant at excluding unwanted light, Narrowbands are typically considered a slightly more premium choice due to their higher performance and durability. This is due to their structure, the narrower the filter the better, and ability to transmit heat and ultraviolet rays.
In many ways a Narrowband filter is not usually necessary, but depending on your level of experience, the clarity you seek and your budget then they may be an option.
Baader Planetarium UHC-S Nebula Filter (Editors Choice)
First on the list and the best Astrophotography filter I have ever purchased. The Baader Planetarium UHC-S Nebula Filter is the standout editors choice; due to a combination of factors; both performance and structure. I personally use it all the time and have excellent results whether I have used it for viewing, imaging and/or Astrophotography.
The Baader UHC-S Nebula Filter provides high-contrast and seamless views of emission nebula, planetary nebulae and supernova remnants but it does so without too much dimming which can result in the loss of background stars. It works so well in even the most light polluted skies, but it also works very well to boost contrast of nebula even if used in darker skies.
Baader are a premium manufacturer, and utilize advanced technology coatings for the best optical quality. As such, you can expect the filter to obtain a transmission higher than 97% across the entire passband, along with complete blockage of very light polluted lines. What this essentially means for you is that you get to experience maximum image brightness and contrast; giving you clear views and photos of deep sky objects.
The major benefit is the usage of this filter on different telescopes, from 4″-10″ and beyond. Whilst it works best on telescopes of 6″ or more Aperture (darkens the entire field of view) its great on smaller Aperture telescopes.
Baader Planetarium H-Alpha 7nm Narrowband Filter
The Baader Planetarium Narrowband 7 nm H-Alpha Filter is one of the most premium light blocking filters available on the market. If you have some extra cash then will most likely be the best one to get.
Due to the multi-layer dielectric coatings that are plasma-assisted and have been hardened via an ion beaming technique; the Filter coatings will never downgrade. As such; these will likely last you a lifetime. They are very durable, high quality filters.
You can expect to receive filters that provide no Halos, reflections or ghosting – thereby being perfect for Astrophotography!
Being a Narrowband filter (which have revolutionized photography for the amateur astronomer), you will be able to photograph faint nebula even in the most light polluted skies and even if you are using a small telescope. By combining the exposure of each color of the various emission lines – Baader have essentially made expert astronomical equipment affordable.
By having a narrow emission area and a spectral half width, you will be capturing only the light emitted or reflected from deep sky objects.
Moreover, Baader line-filters reduce the brightness of the brightest stars to ensure your photos are not tarnished with reflections and halos. This is all made possible due to a complex and quality structure of coating layers, which is what this filter is essentially providing.
This is a premium filter that will arrive in the signature Baader filter box, that comes foam padded for extra protection. Unlike other narrowband filter manufactures who have been criticized, you will get exactly the right bandpass which is Hydrogen-alpha (Red). No off-band light can seep through.
All in all this is a finely crafted, well constructed and premium light pollution filter.
- Narrowband so enhanced performance and durability over a bandpass
- Multi-layer dielectric coatings are plasma-assisted and ion beam-hardened using the latest technology
- High Quality tested to comply with MIL-specifications.
- All Baader filters have individual coating sealed edges, impermeable against ageing because the penetration of moisture is impossible.
- Completely scratch resistant and can be cleaned as often as required.
- More expensive than other filters on the list
I hope you enjoyed this article on the best light pollution filters, and I hope you found it helpful and informative!
Ultimately, each and every filter on this list has been reviewed, compared and thoroughly researched to ensure that you can get a filter that provides you with only the best views and photos. All filters are available in both 1.25″ and 2″ sizes.
When it comes to buying a light polluting filter, there are a few things to be aware of to ensure it works as expected.
If by now you are yet to make a decision, here are the last couple of the things that can help you make your choice.
With light pollution filters, typically the more expensive the better. This is because they tend to be better constructed, are better coated, have better optics and will last a lot longer.
To conclude, its always best to stick with the well respected astronomy equipment manufacturers like Orion and Badaar. Not only do they have a wealth of positive reviews, but they undertake rigorous quality testing and can provide documentation regarding their high standards.
This is why I would look no further than the Baader Planetarium UHC-S Nebula Filter, which I can personally confirm is brilliant, or if you have the budget you may want to stretch to the Baader Planetarium H-Alpha Filter.