SkyTech Quad-Band EOS Clip Filter for DSLR cameras (including astro-modified) Narrowband Bi-Colour imaging is a growing new trend in astrophotography, especially popular in light polluted areas, or for imaging in rural areas in moonlight.

Now you can capture the two main emission nebulae bands at the same time, whilst suppressing light pollution, moonlight, and airglow. Capture more data in less time, and open up your imaging time window - even into the summer months.

SkyTech Quad Band filters work by isolating the primary nebulae emission zones in the red and blue/green wavelengths, and separating them into two main "zones" with a wide separation for easy capture with a colour camera - all in one exposure! Not only is capture very convenient, but processing is easy too, thanks to the wide separation of the green/blue and red "zones". Light pollution control is extremely effective and LED light is also significantly reduced, thanks to the effects of Rayleigh scattering.

Quad Band - combines Sii AND Ha into a red zone, and H-beta + Oiii into a green/blue zone. These zones are easy to process and enhance with your choice of colours.

Why choose a SkyTech Clip-Filter?
It can be inserted or removed in seconds. All lens functions (focus, preview screen, image stabilization) work as usual.
If you have a telescope with short space between reducer/flattener and camera and filter wheel, a clip filter is the solution.
It protects your sensor from dust build-up during long exposures when the mirror is up.

Technical Data:

• Precision CNC housing.
• Schott glass substrate material with precision polish.
• Glass thickness 1.0 mm.
• Surface Quality: 60/40 (Refer to MIL-O-13830)
• Fine-optically polished to ensure accurate 1/4 wavefront and < 30 sec parallelism over both surfaces
• Negligible transmission of off-band, including the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm).

Dichroic Filter Coatings:
Multi-layer anti-reflection coating (AR Coat). Additional UV IR Blocking layer.
Special high homogeneity coating process with electron-beam gun evaporation and Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL (central wavelength) no deviation with temperature change.

Quad-band OSC filter CWL:

• 1st band, CWL495nm FWHM35nm
• 2nd band, CWL 660nm FWHM 35nm
• 1mm thick optical glass with 30 arc sec parallelism.
• UVIR Block and Anti-Reflection Coating.

Compatible with all APS-C sized Canon EOS cameras. Not for full frame cameras. Do not use with EFS lenses because the rear elements can strike the filter.