Omegon Pro 1.25″ OIII CCD filter
Have you ever looked at an image of the Veil Nebula or the Dumbbell Nebula and wondered how photographers managed to capture such incredible detail? The answer is often simple: the right filter. The Omegon Pro 1.25″ OIII CCD filter belongs to the professional Pro series and is designed precisely for situations where you want to get the most out of your telescope or astrograph - whether you are observing visually or imaging with a camera.
How the OIII filter works
The OIII filter (doubly ionized oxygen) transmits a very narrow band of light around wavelengths of 496 nm and 501 nm. This emission is characteristic of planetary nebulae, supernova remnants, and parts of emission nebulae. Thanks to its extremely selective passband, the filter effectively suppresses light pollution from cities, sodium and mercury vapor lamps, and the natural glow of the night sky (airglow). The result is a dramatically increased contrast between the object and the background - even from suburban locations or less-than-ideal observing sites.
Optimized for CCD and CMOS cameras
The Omegon Pro OIII CCD filter is optimized for use with CCD and CMOS cameras, whose sensitivity differs from that of the human eye. This means that the passband width and anti-reflection coating are tuned to work as effectively as possible with modern sensors - from planetary cameras to cooled astrophotography CCDs. At the same time, it can also be used advantageously for visual observation, where it will highlight structures in planetary nebulae in a way that may genuinely surprise you.
Recommended objects for OIII observation
This filter is primarily intended for observing and imaging planetary nebulae and supernova remnants. It performs exceptionally well on objects such as:
- M57 - Ring Nebula
- M27 - Dumbbell Nebula
- NGC 7293 - Helix Nebula
- NGC 6960 / NGC 6992 - Veil Nebula
- Cassiopeia A
Note: the OIII filter is not primarily intended for hydrogen nebulae (H-alpha emission) or comets. For those objects, choose an H-alpha or broadband filter instead.
Build quality and mechanical design
The filter body is made from quality aluminum, which ensures low weight, mechanical durability, and trouble-free threaded connection to 1.25″ accessories - eyepieces, camera adapters, or filter drawers. The precisely machined thread prevents the filter from tilting, thereby avoiding image quality degradation caused by the optical surface being angled.
Key features at a glance
| Filter type |
OIII narrow band |
| Thread size |
1.25″ |
| Transmission peak |
496 nm and 501 nm |
| Optimized for |
CCD and CMOS cameras, visual observation |
| Best for |
Planetary nebulae, supernova remnants |
| Body material |
Aluminum |
| Coating |
Anti-reflection, precision multi-layer |
Who is this filter for?
The Omegon Pro OIII CCD filter is ideal for experienced astrophotographers working with emission objects who want to maximize contrast in the ionized oxygen band. It is equally valuable for visual observers who want to draw out details in planetary nebulae from both dark and light-polluted skies - details that would otherwise blend into the background. Thanks to the standard 1.25″ thread, it can be used without any issues with the vast majority of common eyepieces and camera adapters available on the market.
About the Omegon Pro series
Omegon is a brand with a long tradition in astronomical optics and accessories, built on careful material selection and precision craftsmanship. The Pro series represents the top of their range - filters designed for demanding users who do not want to compromise on the quality of optical glass, coating accuracy, or mechanical execution. Omegon offers a wide range of accessories for astronomers of all levels, from beginners to professionals, and its products are available throughout Europe with solid service support and a network of specialized retailers.
