Astronomik Canon EOS XL CLS clip filter
If you photograph the night sky from a city or from locations affected by the orange glow of street lighting, the Astronomik CLS Clip Filter for Canon EOS XL is exactly what you are looking for. This broadband filter from the CLS (City Light Suppression) series was designed to suppress the most disruptive components of artificial lighting - primarily sodium and mercury vapour lamps - while passing the light emitted by emission nebulae, star fields and other deep-sky objects. The result is noticeably more contrasty images with richer detail, even when your observing site is right on the doorstep of a major city.
Clip-in mounting - use with any lens
One of the greatest advantages of this filter is its mounting system. Thanks to the Clip design, the filter simply slides directly into the Canon EOS XL camera body in front of the sensor, so it can be used with any lens - from wide-angle optics to telephoto lenses and even astronomical telescopes with a T2 adapter. There is no need to purchase a separate filter for each thread diameter. The filter frame is made from lightweight yet durable aluminium, ensuring precise seating and a long service life without any risk of deformation.
Optical quality and spectral characteristics
The filter features multi-layer anti-reflection coatings on all optical surfaces, minimising unwanted reflections and ghost images in your shots. The coatings are applied to high-quality optical glass with very low wedge error, so the filter does not degrade sharpness even when used with fast optical systems.
The CLS filter transmits the following spectral bands:
| Spectral line |
Wavelength |
| H-alpha |
656 nm |
| H-beta |
486 nm |
| OIII |
496 nm and 501 nm |
| Continuous stellar light |
broadband |
At the same time, it blocks the emissions of sodium lamps (589 nm) and mercury lamps. The filter is suitable both for astrophotography and for visual observation - even when looking through an eyepiece you will notice a clear improvement in sky background contrast.
Who is this filter ideal for?
The Astronomik CLS Clip is an excellent choice for astrophotographers who work with unmodified Canon EOS XL bodies and are looking for a quick and convenient way to improve image quality without any permanent modifications to their camera. It is especially appreciated by those who photograph emission nebulae such as:
- Orion Nebula
- Lagoon Nebula
- North America Nebula
These are objects where suppressing the veil of light pollution delivers an immediate and dramatic effect. The filter is also well suited to beginners in astronomy who want to take their first step towards better astrophotography without a large financial investment.
Effective light pollution reduction at an accessible price
Reducing light pollution with a CLS filter is one of the most effective and affordable ways to significantly improve the quality of astrophotos taken under light-polluted skies. Add this filter to your kit and you will see the difference in your very first image.
About Astronomik
Astronomik is a German manufacturer of premium astronomical filters with a long-standing tradition and a solid reputation in the astronomical community worldwide. Astronomik filters are produced with an emphasis on precise optical performance, accurate spectral characteristics and mechanical durability. Every filter undergoes rigorous quality control, allowing astronomers and astrophotographers to rely on consistent results under any conditions. Whether you are an occasional observer or an experienced astrophotographer with demanding requirements, Astronomik offers a product that meets expectations - and often exceeds them.
