Light pollution clip-on filter for full frame Nikon DSLR cameras

The Hong Kong based company Cyclops Optics is selling light pollution filters for Nikon full frame cameras. The filter can be "clipped-on" on top of the sensor in order to block light pollution for astrophotography.

Update #1: This clip filter was made by STC and not by Cyclops Optics. Cyclops Optics is one of the resellers in Hong Kong. STC is a Taiwanese company and their website can be found here. Some tests can be found here.

Update #2 from a reader: the clip filter is actually inserted during sensor cleaning mode. The mirror flips up and it sets almost level with the electric contacts. The filter bracket holds the mirror up after cleaning mode is disabled allowing for live view mode only. This solution works well with the D810 and D810, but not with the D610.

A new STC MS Clip filter V2.0 is coming soon: the new version will not require the mirror to be locked up and thus should work with D610 and other models.

Additional information from the product listing on their website:

STC Astro-Multispectra Clip Filter for Nikon full frame bodies is a novel light pollution filter designed by STC Optics with transmission characteristics designed by professional astronomer and renowned astrophotographer Dr. Wei-Hao Wang. Placing the light pollution filter closer to the sensor reduces color shift that may occur at the peripheral areas of the image. The clip filter design also offers We recommend using STC Clip Filter–Nikon FF–Astro MS with SLR lenses of focal distance 30mm or longer, and avoiding directly taking pictures to strong artificial light which causes slight flare on image.

The material is A2 stainless steel which is virtually non-magnetic and less brittle at low temperatures. Specially designed Clip-shaped structure could be pressed firmly while attaching the lens on camera body. Therefore, the paralleled focal plane could ensure focusing performance clearly.

It is coated by the use of the IBAD (Ion beam-assisted deposition) technology on Schott B270 optical glass, working for higher durability and easily cleaning. It will significantly reduce the interference from artificial lighting, such as mercury and sodium street light, yet allow the important nebula emission lines to pass, thus enhancing the contrast of astronomical objects.

Compatible Nikon bodies:

  • D4 / D4s
  • D800 / D800E
  • D810 / D810A
  • D750
  • D600
  • D610


  • Clip Filter is designed for Nikon Full-Format cameras. Mounting and removing the Clip-Filter is quick and easy. The color shift problem that may occur due to the wide angle SLR lens in peripheral areas of the image could be reduced. The recommended SLR lenses focal length is 30mm or longer.
  • The material is A2 stainless steel which is virtually non-magnetic and less brittle at low temperatures. Specially designed Clip-shaped structure could be pressed firmly while attaching the lens on camera body.
  • STC Astro-MS Clip filter can reduce the interference from artificial lighting in the city ,and enhance the wavelength of Hα, Hβ, OIII and SII. (Hα=656.3 nm, Hβ=486.1 nm, OIII=495.9 & 500.7 nm, SII=672.4 nm)
  • It is coated by the use of the IBAD (Ion beam-assisted deposition) technology on Schott® B270 optical 2mm glass, working for higher durability and easily cleaning, and preventing aging variation in optical spectral characteristics due to temperature and humidity change
  • High-quality double-sided NANO Anti-smudge coating provides excellent performance on waterproof and grease-proof capability
    18 months original manufacturer warranty and lifetime warranty on aluminium frame.

Here are a few with and without filter comparisons (direct JPEGs from Nikon D800):


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  • Todd

    Really interesting. I’ll be waiting to see some test results and opinions though.

    • Same here, certainly sounds interesting, but I’d like to see some practical usage reports/reviews as well. Seems to be fairly affordable, at current FX rates it seems to cost ~£170

  • T.I.M

    Maybe easier to put the same filter on the lens itself (or in the telescope’s filter slot).

    • I talked with one of their support people (in the little chat box that shows up on the site) and they said that the lens filters are designed to be used at 100mm or longer, while the clip in filter is for 35mm or longer. I forgot to ask why that is… /facepalm

      • nwcs

        That’s generally true of all light pollution filters. They’re not designed for wide sky stuff but rather deep space objects.

        • Though, their support rep did say that they’ve tested the clip-in filter with a Nikon D750 + 24mm f/1.4 and noticed no vignetting. I’d be skeptical about using my 14mm with it, but for 24mm, I’m highly interested.

          • nwcs

            If you do some searching on the IDAS LPS D1 or P2 and maybe the astrodon filters you’ll find a lot of the info on pros and cons at wide angles. I have seen it work but I’ve also seen it said that you get a lot more gradients in color that are very hard to process out.

      • T.I.M

        I know nothing about Astro photography (the real one, not the moon and the Sun).
        Astro photgraphy and underwater pictures are the 2 photographic fields that I have no experience (and no tools).

        • Spy Black

          Moon and sun photography IS astro photography.

          • T.I.M

            So are landscapes (earth pictures !)

            • Gael C.

              Wow, tanks, I will feel special now, when doing astro-macro-photography 🙂

            • preston

              No, they’re not. Astronomy is the study of celestial objects and phenomena outside the Earth’s atmosphere.

    • James Heskin

      IMHO, this whole concept is silly. Anyone doing astrophotography already has numerous and good filters that don’t need to be put into the camera. If you’re talking about wide angle, your just dealing with some sky bloom, which again, seems a bit silly to risk scratching your sensor.

      • Roland Delhomme

        Not at all; a lot of serious astrophotographers will go as far as full on sensor swaps; this makes a lot of sense on many levels and seems to offer a bandpass to defeat skyglow. For the same reasons an AA filter goes directly over your sensor, instead of further away, this makes more sense the more I think about it. It will be intriguing to see the results, which shouldn’t be long in coming. For those not inclined to use it, they already have the advantage of not having to wait…

        • James Heskin

          As one who does both kinds of photography and has converted DSLR’s and CMOS cameras for astro purposes this still makes no sense to me:

          It doesn’t help the reds that your current filter blocks, it just reduces some sky glow which a 2″ filter can do just as well and you don’t have to fiddle inside of a camera which is a much safer “1 camera” solution in my opinion.

          • Wei-Hao Wang

            This is indeed intended to be used with camera lenses, especially wide-angle ones. Interference filters like this work very poorly if put in front of wide-angle lenses.

            The company indeed has a 48mm version of the same filter, which goes into many telescopes and standard 2″ eyepieces.

          • Wei-Hao Wang

            The sample photos used by this NikonRumor post were shot with the lens version of the same filter, and a 180mm lens. These photos were to show the effect of the filter itself. When these photos were taken, the clip-in version was not even developed. There should be some user photos taken with this clip-in filter now BTW.

      • Nimloth

        A lot of popular filters are made to be inserted just behind the lenses’ last element, i.e. inside the camera.

      • I find your dismissal of the device to be a touch arrogant. It’s clearly not a product designed for casual users and it’s not designed by idiots or to appeal to the shitty-lens-made-of-brass folks. I would assume it works as advertised and at least give them some benefit of the doubt.

  • Photobug

    Nice niche market item. Wonder what the impact will be…we need some real field use and test results.

    • nwcs

      Of course it’s niche. Real astrophotography is a very small subset of photography but we’re rather passionate. Real AP (not starscapes/landscapes) is some of the most difficult photography possible both in setup, execution, and post processing.

      And given how fearful people are of the dark (regardless of the very real health issues of not having dark at night) every little bit that helps helps.

  • nwcs

    These have been out for a long time for Canon cameras so it’s nice to see them on Nikon as well. I’ve been following the tales of them on Cloudy Nights. What people don’t realize is that your color balance will be a bit off as it takes out a lot of red to compensate for light pollution. It’s also mostly effective with some mercury vapor and certain types of sodium lights. LED based lights aren’t blocked at all. And as the dark-fearing public switches to LED it’ll further destroy anyone’s ability to enjoy the night sky.

    • Eric Calabros

      LED is going to win. Its inevitable.

      • nwcs

        I know, and it can be fine if the cities will use the minimal needed luminance and shield it in every direction but down.

        • Ralf

          Sodium lights make for such awful colours in street photography that my first thought was how such a filter might improve available light photography with sodium lights.

          • Nimloth

            Sodium light is essentially monochromatic, so filtering out the sodium light will only make your scene go black, unless there are other light sources nearby. 🙂

          • nwcs

            Hmm, interesting use for one. There will be a difference between high pressure and low pressure sodium lights. You will lose a lot of red, though, so your color balance will need some work.

        • iamlucky13

          Most cities seem to be increasing the illumination levels as they transition to LED. They do get reasonably well-aimed fixtures, but that only reduces the problem. Most already had unshielded streetlights anyways, but reflection of light off the ground is still a major source of skyglow.

          • nwcs

            Yeah, and most of it is so incredibly wasteful and almost entirely unnecessary as studies have shown.

      • Unfortunately. Way back I was very happy about LED, but seeing how they are being abused in many fields…

        But hey, gennie’s out of the bottle, so we have to deal with it somehow.

  • thomas

    Now make it with IR filters

    • Mikycoud

      Indeed! And UV…

  • What does this mean?
    “The clip filter design also offers We recommend using STC Clip Filter–Nikon FF–Astro MS with SLR lenses of focal distance 30mm or longer …”

    • RC Jenkins

      This article is a strange coincidence because I was just looking at these 2 days ago..!

      Anyways, that means that they also offer a clip filter design (instead of a traditional filter on the front of the lens (they offer both types). This picture above is the clip filter.

      Also, they only recommend using the filter for 30mm or longer lenses, because you can get some very strange color effects towards the edge on wider FoV.

  • One of the reasons to put it on the sensor is cost. These kinds of filters have been around for decades for the astronomy community, but they are usually two inches in diameter, max. Most folks use an inch and a quarter size. Making these in sizes like 55mm or 67mm or whatever could get pricey. And of course there are the wide angle lenses with no practical way to put a filter over the lens.

    • nwcs

      Yes, usually they are 48mm but some like the IDAS LPS D1 are available up to 77mm. That would be great for camera trackers although most dedicated people would be attaching the camera to the telescope focuser where 48mm is standard.

  • sickheadache

    I will apply what I was taught many moons ago..never ever, ever never touch that mirror. It would seem…adding an object on top of a mirror would..spell disaster. Plus maybe if something did go would effect your own warranty with manufacture. Added weight to a delicate mirror..would seem like it would misaligned.

    • Eta76

      Sensor, not mirror. Mirror is continuously flipping. Sensor will be fixed to the body 🙂

      • sickheadache

        OH…this is me not paying attention..this attaches onto the Sensor? Well I learned many Moons ago..never touch that sensor…lol

  • Nimloth

    That figures nicely into my (not necessarily anyone elses) dream of a Nikon mirrorless camera: Basically, keep the F-mount, and use the real estate formerly occupied by the mirror to hold different filters. 🙂

  • Fango

    you are better off investing in a filter wheel for 2″ or 1.25″ filters

    • nwcs

      Not really… Sure the Ha and SII and OIII bands aren’t affected as much but the LRGB would still have a lot of light pollution impact. You’ll get a much better result at the cost of more complexity and time required at night. Always a trade off…

    • Wei-Hao Wang

      This filter is intended to sit between the lens and the sensor, for wide-angle shots. For this particular application, there is no way one can add a filter wheel between a lens and a DSLR. For telescopes, many of them can directly accept a 2″ (48mm) filter. So no need for a filter wheel either, unless you are using a dedicated monochrome CCD or CMOS camera.

  • galopin

    Funny enough, i bought this last week, but now i am a little scared to use it, as the manipulation require to go live view and it then block the mirror. I am afraid that once the camera time out live view, the mirror would break trying to get back in place !

    The filter has to be inside for wide angle because it is an interference filter, not in the mass of the glass, it bounces specific wavelength. At wide angles, it is enough bias in the thin layer traversal difference to reject tho wrong wavelenghts.

    i will try early next year, for the moment, my xmas detour in death valley should not need such an extreme filter to get rid of light pollution compared to LA 🙂

    • Mateusz Antonowicz

      There should be an option on your camera called ‘mirror up’. Just switch it on, click the shutter, and mirror will go up. And it will stay that way until you press the shutter again or your battery will be depleted. So you have a whole lot of time to see and attach the filter to the sensor. This method is used to actually clean sensors, it’s nothing new. Don’t ever go to live view for sensor manipulation!

      • galopin

        This is not the problem, i use the mirror up to clean my sensor from time to time already. My concern is not about installing the filter, but what happen if when in place, i turn off the camera for example. In that case, the mirror is supposed to drop but with the clip, it is blocked, so, will it break, or just mirror up is a physical action and letting it go down when it is keep in place is safe ?

        • Mateusz Antonowicz

          Nah man, look. You only use Mirror Up to install the filter, then you can put the mirror down. There is space between a mirror and sensor, so with filter installed mirror can go up and down without problems, because the filter is firmly placed on top of the sensor. There is no way that this filter would hit the mirror, it’s thin, and there is space there, so you can safely install it, and shoot normally, handheld, mirror up, whatever you want. After the shoot you can do mirror up again and remove filter. It’s simple. Nothing can break. Just google cross section of a DSLR, and you will see how much space is there.

          • galopin

            You should look better, the filter does not slide inside behind the mirror, the little round piece stick to the hollow round part in the body, and there is a little right angle to keep it in place at the top, this does not slide in at all, this keep the filter in front, and the top of it will hold the mirror from going down ! As seen here, at the top, there is the mirror where the filter would hold, and the round part at the bottom :

  • Konrad Großkopf

    Now i want a clip in nd filter!

  • Nikoniser

    No thanks ! :


    (Lensrentals insider joke: What do you call a D800 with a scratched
    sensor? Parts. Because at $1,800 for a sensor replacement . . . )

  • GearHeavy

    Someone please make an “In-Law” clip-on that will make my mother-in-law look like a kitten.

  • so does this clip in with mirror up, if the mirror should come down due to battery or something else what are you left with, damage?

    • Mateusz Antonowicz

      Attaching that would take like 1 minute max and then you just close the mirror. Nothing will break if the mirror drops, because the filter sits on top of sensor. You only use mirror up to attach it, and then you just shoot, like you would normally.

  • Update: This clip filter was made by STC and not by Cyclops Optics. Cyclops Optics is one of the resellers in Hong Kong. STC is a Taiwanese company and their website can be found here:

  • RC Jenkins

    I saw this a few days before the post here, and I do think this is very interesting; but to anyone interested, there is a “poor person’s solution”: software processing. 🙂

    It won’t be exactly the same, but it can do wonders as well.

    For example, here’s what I was able to accomplish by simply filtering out the greenish cast on an image I took earlier this year:

    I’ve confirmed that I can do something similar for the sample images above as well. 🙂

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