ALTAIR ASTRO PLANET-KILLER F125IRP685CCD ALTAIR ASTRO PLANET-KILLER F125IRP685CCD filter with anti-reflective coating

The Altair Astro Planet-Killer 685nm Premium IR Pass Filter is designed to provide sharper lunar and planetary images with monochrome CCD or CMOS cameras. Unusually for a filter of its type, the Altair Planet Killer has an AR coating to enhance contrast.

It works by reducing image distortion caused by the atmosphere by passing 685 nm and longer IR wavelengths that are less affected by air currents. It also eliminates blue background glare, both day and night, for very high contrast daytime lunar or planetary images.

This reduces the blurring effects of poor vision for noticeably sharper lunar, planetary or guide star images, even near the horizon. Especially good for CMOS cameras with high infrared sensitivity, such as the Altair Hypercam and GPCAM mono cameras.

See the two example images (click on the thumbnails) to see the dramatically improved sharpness and detail on Jupiter and the Moon.

When used as a luminance filter with planetary RGB filter sets, extremely fine detail is revealed. When used during the day, lunar and planetary objects appear against a dark background. For monochrome images of the Moon, day or night, the Planet Killer filter is all you need.

Another possible application is autoguiding at long focal lengths, to reduce the effects of air motion on the guide star. In theory, this would improve tracking information, as the guiding camera would stop "chasing" seeing (air currents) instead of mount movements.

Advanced AR coatings reduce halo effects and internal reflections.

Technical Specifications:

• Batch tested to ensure uniformity.
• High quality dichroic/dielectric coatings.
• Anti-reflection coating to reduce stellar halos.
• UV/IR blocking for imaging
• Ultra-thin glass from Schott Germany.
• Precision CNC machined filter cell for stress and tilt free mounting.
• Weight: 0.1 kg