PureNight® Premium Light Pollution Reduction Filter by Lonely Speck

Lonely Speck PureNight Light Pollution Reduction Filter

Enjoy better night sky images with PureNight®.

PureNight is a premium glass light pollution reduction filter designed by Lonely Speck. Made of a special didymium glass, PureNight reduces the transmission of light from sodium vapor lamps, one of the most prevalent sources of light pollution on our planet.

Resulting images will have truer colors and improved contrast when compared to images influenced by light pollution.

Lonely Speck Pure Night Light Pollution Filter
85mm PureNight Filter mounted via the Formatt-Hitech 85mm Filter Holder. Please note that production versions of PureNight may differ from our prototype shown here.

Sample Images

Below are example photos taken with and without the PureNight installed.

These photos were made in Tekapo, New Zealand, home of the world’s largest dark sky reserve and some of the darkest skies in the world. Even so, PureNight makes a dramatic improvement by reducing the effects of light pollution on the image.


Lonely Speck PureNight Light Pollution Reduction Filter Example Without Filter Lonely Speck PureNight Light Pollution Reduction Filter Example With Filter

Both of these photos were exported straight from RAW files with no edits whatsoever. A one stop increase in ISO was used on the filtered image to compensate for the decrease in brightness in the overall image due to the reduction of light pollution. All other settings were identical. First image: Sony a7S, 18mm f/2.8, 25s, ISO 3200, Daylight WB. Second image: Sony a7S, 18mm f/2.8, 25s, ISO 6400, Daylight WB. You can download the full resolution RAW images here (.zip, 24.1 MB). They’re in DNG format so they should be editable on most RAW editors like Adobe Lightroom or Camera RAW.

More Comparisons

By popular request, here are a couple more comparisons of astrophotos shot with and without the PureNight.

lonely-speck-pure-night-light-pollution-reduction-filter-example-alabama-hills-no lonely-speck-pure-night-light-pollution-reduction-filter-example-alabama-hills-with

These photos, as with the first samples, were exported directly from RAW with no edits other than a brightness equalization with a 0.7EV push on the PureNight shots to compensate for the reduced brightness of the light pollution.


Once again, If you would like to download the full resolution versions of these images to play around with, download the full resolution RAW DNGs here (.zip, 73.2 MB).

How It Works

PureNight is made of a special type of glass called didymium glass. PureNight mounts in front of your camera lens with a standard square filter holder (sold separately).

PureNight greatly reduces transmission of yellow and orange light in the 575nm to 600nm wavelengths, the same wavelength of light that is emitted by high pressure sodium vapor lamps. Sodium vapor lamps are most commonly used on street lights and industrial lighting fixtures and so they are one of the most prevalent sources of light pollution for astrophotography.


Our PureNight filter will reduce the effect of light pollution in your astrophotography for truer colors straight out of the camera. Photos made through the PureNight will have improved contrast and reduced haze from light pollution.

Premium Optical Quality

PureNight is precision ground and polished and features an anti-reflective multi-coating to greatly reduce the effect of internal reflections and ghosting that plague most filters when used at night with bright light sources in the image.


Mounting PureNight

PureNight is a universal square filter available in 85mm, 100mm, and 150mm sizes. PureNight requires a square filter holder and the appropriately-sized system adapter ring to fit your lens (see recommendations below).


Like the SharpStar2, PureNight is made to fit into the most popular square filter systems in 85mm, 100mm and 150mm sizes.

If you don’t already have a filter system, here are some recommendations:

85mm (lenses up to filter diameter of 77mm):

Formatt Hitech 85mm Aluminum Holder (Amazon / B&H) and Formatt Hitech Adapter Rings for 85mm Aluminum Holder (Amazon / B&H)

100mm (lenses up to filter diameter of 105mm):

Formatt Hitech 100mm Aluminum Modular Holder (AmazonB&H) and Formatt Hitech Adapter Rings for 100mm Holder (Amazon / B&H)

150mm  (certain wide angle lenses with fixed hoods):

Haida 150mm Filter Holder (Amazon / B&H)
Lee SW150 Filter Holder (Amazon / B&H)
NiSi 150mm Filter Holder (Amazon / B&H)

A Crowdfunded Project

We launched PureNight as a crowdfunded project with a close date of December 31, 2016 for our early bird pre-orders. Thank you to all of our early supporters! Crowdfunding is what made PureNight possible.

Our first project, the SharpStar, was a crowdfunding success as well, and we’re happy that PureNight has proven successful too.

Now Available

PureNight filters are now available, exclusively via the Lonely Speck website, in the following sizes:

PureNight Sizes

85mm square filter — $264

(Compatible filter systems: Cokin P, Formatt-Hitech 85mm)

100mm square filter — $289

(Compatible filter systems: Lee 100, 4″x4″, Formatt-Hitech 100mm, Cokin Z-Pro)

150mm square filter — $459

(Compatible filter systems: Lee SW150, NiSi 150mm, Haida 150mm)


100% Product Guarantee

If you’re not satisfied with your order for any reason, contact us and we’ll make it better with a free replacement (if stock is available) or return for a refund.

Sold Exclusively on lonelyspeck.com

PureNight® is a registered trademark of Ian Norman, DBA Lonely Speck.

The PureNight light pollution filter is sold exclusively on lonelyspeck.com by Ian Norman and Diana Southern, creators and owners of the Lonely Speck blog and the PureNight filter. Any other website or store selling a light pollution filter under the PureNight or any other name is not an authorized seller of Lonely Speck’s light pollution filter, and the product being sold is not manufactured or sold by Lonely Speck or covered by the Lonely Speck 100% satisfaction guarantee. For questions or comments, please email us at [email protected].

Your order will include:

  • PureNight® Light Pollution Reduction Filter
  • Protective Case

NOT included: filter holder and adapter ring (sold separately, see recommendations above)

Questions? Check out our PureNight FAQ

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