The 40.5mm Natural Night Filter from NiSiis designed to reduce the appearance of light pollution in images or video that include the night sky and illumination from artificial light sources. This effect can be obtained when this filter is used on a film camera system with daylight film installed, or on a digital camera system with its daylight white balance setting selected.

Light pollution occurs in areas of the night sky that are above or near concentrated and intense sources of artificial light such as cities. These light sources can include exterior and interior lamps for commercial or residential buildings, brightly lit advertisements such as billboards, streetlamps, as well as sports and entertainment venues. Together, they can result in a type of light pollution known as skyglow, where individual stars, the Milky Way, and other astronomical features in the night sky are obscured. Additionally, artificial lights clustered together can become difficult to individually discern. Light pollution from these "cluttered" sources can become a source of distraction within an image and can resemble overexposed areas of glare.

When used, the NiSi 40.5mm Natural Night Filter can improve the results of nighttime images by blocking the yellow light from sodium-vapor lamps, mercury-vapor lamps, or low Color Rendering Index LEDs, common light sources within urban areas. By preventing the dominant wavelengths of light associated with the color of those lamps from being recorded, the visibility of astronomical objects is enhanced, and artificial light sources are more clearly defined with less glare and improved contrast.

This NiSi 40.5mm Natural Night Filter is constructed from optical glass for clarity as well as color fidelity. Each glass surface includes nano coating for reduced glare and improved color transmission. The nano coating also incorporates resistance coating for an improved beading effect with water or oil for easier cleaning, plus resistance to scratches and abrasions.

Reduces Light Pollution in Night Sky    Blocks Yellow Sodium-Vapor Light    Blocks Yellow Mercury-Vapor Light    Blocks Yellow Light from Low CRI LEDs    2x Filter Factor, 1-Stop Correction    H-K9L Optical Glass Construction    Nano Coating and Resistance Coating    Aluminum-Alloy Filter Ring    40.5mm Front Filter Threads    Plastic Case

• Reduces the appearance of light pollution in images or video that include the night sky and illumination from artificial light sources
• For cameras with daylight film installed, or a digital camera system with its daylight white balance setting selected
• Blocks the yellow light from sodium-vapor lamps, mercury-vapor lamps, or low Color Rendering Index LEDs, common light sources within urban areas
• Enhances the visibility of astronomical objects, and where they appear, artificial light sources are more clearly defined with less glare and improved contrast
• Approximately 2x filter factor reduces exposure by 1 stop
• Constructed from optical glass for clarity
• Each glass surface includes nano coating for improved light transmission
• Resistance coating for improved beading with water or oil for easy cleaning
• Resists scratches and abrasions
• Aluminum-alloy filter ring for durability while remaining lightweight
• 40.5mm front filter threads allow for use with other filters
• Plastic case included for storage and transport

Related Questions and Answers

Q: 1. Does this fit the NiSi 100mm Filter Holder for Sony FE 14mm f/1.8 GM Lens?

A: Yes, the NiSi 100 x 100mm Natural Night Light Pollution Filter would be compatible for use inside the NiSi 100mm Filter Holder for Sony FE 14mm f/1.8 GM Lens.

Q: 2. I saw that there is another version of this filter with an aluminum frame. What is the frame of this filter made of?

A: The NiSi 72mm Natural Night Filter ring is made out of aluminum.

Q: 3. Does anyone compares this Nisi Natural night filter with Breakthrough photography "Autumn & Night Sky" filter?

A: The NiSi is a great filter. High quality and it's sharp. It does have a pink-ish color cast while the Breakthrough Photography is more warm and sometimes orange-ish. Both are really good filters though.

Q: 4. Are you certain this will work with my Sigma 500mm f/4? That lens only takes a drop-in 46mm mounted on rear of lens.

A: Yes, the NiSi 46mm Natural Night Filter will work on the Sigma 500mm f/4 DG OS HSM Sports Lens.

Q: 5. Is this compatible with Sigma 500mm f/4 rear drop-in filter holder?

A: Yes, the NiSi 46mm Natural Night Filter should work with the Sigma 500mm f/4 DG OS HSM Sports Lens.

Q: 6. did anyone notice any vignetting issue when using ultrawide angle lenses, such as Nikon 16-35mm f/4, specially at 16mm?

A: When mounted on the Nikon 16-35 f/4 there does not appear to be any vignetting at 16mm.

Q: 7. does this filter fit on the nikkor 70-300 f4.5-6.3 lens for nikon cameras?

A: The Nikon AF-P DX NIKKOR 70-300mm f/4.5-6.3G ED VR Lens uses a 58mm filter in front. The NiSi 58mm Natural Night Filter is a better choice. https://bhpho.to/3juKIAh

Q: 8. Two questions: (1) how thick is this filter, neglecting the thickness of the threads; and (2) why is the "filter factor" 0.6 to 1.5 stop instead of a constant value?

A: The frame is 6.2mm. But once threaded into the lens it is about 3.8mm. And the light loss is just under a stop.. It is not a range.

Q: 9. is this filter necessary for nighttime videography? And is it worth buying this filter for video or you can do all of the color adjustments in post where you could remove the light pollution and grade to a natural night color?

A: If are shooting on locations at night with light pollution it is best to use a filter like the NiSi 67mm Natural Night Filter. editing in post will not be as good.

Q: 10. does this filter pass 5577 angstroms? I wish to pass 5577 for auroral photography, but otherwise block Na 5890 & other street lamp emissions. Maybe i can get a transmission spectrum for this filter? Otherwise, can you recommend an ideal auroral/light pollution filter? thank you.

A: Unfortunately, for whatever reason NiSI does not list the angstroms for this filter. However, I would take their word that it is: Reduces Light Pollution in Night Sky, Blocks Yellow Sodium-Vapor Light, Blocks Yellow Mercury-Vapor Light, and Blocks Yellow Light from Low CRI LEDs. If it does not, they will lose customers.