Omegon Pro 1.25″ CLS Filter

Omegon Pro 1.25″ CLS filter

If you observe or photograph the night sky under light-polluted conditions, you know how frustrating it can be to stare at a washed-out, orange-tinted sky instead of stunning nebulae and star fields. The Omegon Pro CLS (City Light Suppression) filter was designed specifically to solve this problem - it selectively suppresses wavelengths characteristic of sodium and mercury vapor lamps, LED street lighting and other sources of artificial light, while transmitting radiation from astronomically interesting objects.

Broadband performance with natural color

CLS belongs to the category of so-called broadband filters, which means it does not work as selectively as narrowband filters such as H-alpha or OIII, but instead passes a wider portion of the spectrum. This brings a key advantage: stars retain their natural colors, the overall contrast of the scene increases, and nebula details stand out from the background more clearly than without a filter. The filter is particularly effective when observing and photographing planetary nebulae, where it helps separate emission light from the disturbing sky background.

For visual observers and astrophotographers alike

For visual observers, the CLS filter delivers an immediately noticeable effect - contrast increases and diffuse objects such as nebulae become more visible even through low-magnification eyepieces. Astrophotographers will appreciate that the filter works with both monochrome and color cameras as well as DSLRs, effectively suppressing the dominant orange cast caused by light pollution in images taken from cities or their surroundings.

Build quality and compatibility

The filter body is machined from aluminum, ensuring low weight, corrosion resistance and precise thread tolerances. The standard 1.25″ thread allows direct screwing into eyepieces, camera adapters or nosepieces. The filter fits any equipment with a 1.25″ focuser without the need for additional adapters. The build quality matches the Pro series standard - the optical surface is precisely ground and coated with multi-layer coatings to minimize reflections and maximize transmission in the desired bands.

Who is this filter for?

The Omegon Pro CLS is an ideal choice for astronomers observing from suburban or urban locations who want to get the most out of their telescope without having to travel far to dark skies. It will be appreciated by:

• Beginners looking for a simple way to improve image quality
• Experienced astrophotographers working with refractors, reflectors or catadioptric telescopes with a 1.25″ focuser
• Visual observers wanting better contrast on deep-sky objects from city locations

The broadband CLS filter is an excellent first step into the world of astronomical filters - it offers a visible effect without dramatically reducing light transmission or complicating image processing.

Ready to use straight out of the box

The filter requires no special setup or calibration - simply screw it into an eyepiece or camera and start observing immediately. Combined with other filters from the Omegon Pro range, you can build a complete filter system tailored to specific types of objects and observing conditions.

About Omegon Pro

Omegon is an established brand with a clear focus on the needs of amateur astronomers - from compact telescopes and mounts to accessories and filters. The Pro series represents the top of their filter range: precise optical manufacturing, reliable aluminum bodies and carefully designed spectral characteristics ensure you get exactly what is promised. Omegon places strong emphasis on performance-to-price ratio, making professional features accessible to observers with a realistic budget. If you are looking for a filter that truly works and lasts season after season without compromise, the Omegon Pro CLS is a choice you will not regret.

Technical specifications