Askar ColorMagic Duo-Band Narrowband Imaging Filter - 2"

The Askar Duo-band narrowband, as its name suggests, has two passbands, which is quite different from those single-band narrowband filters thus more economical and efficient because astrophotographers don’t need to purchase a filter wheel or a whole narrowband filter set. And imagers don’t have to buy a monochrome astronomy camera as the duo-band narrowband filter goes well with ordinary color cameras. So the duo-band filter is an economical admission ticket for astrophotography lovers into the world of narrowband technology and deep-sky object imaging.

The Askar duo-band filter is suitable for imaging emission nebulae, planetary nebulae and supernova remnants. The Askar duo-band filter has an extreme high transmission at a center wavelength of 500.7nm (O III) and 656nm (H-alpha). Narrow bandwidth enables this astroimaging filter to block all the light pollution and other unwanted artificial lights or night glow. So the Askar duo-band filter is an ideal instrument for astro-imaging in heavily light-pollution hit locations and delivers enhanced contrast at darker places.

The Askar duo-band filter is designed for improving the contrast and details of nebulae and supernova remnants. Featuring narrow bandwidth and a greatly high transmission at a center wavelength of 500.7nm and 656nm, the Askar duo-band filter can bring out the highest amount of details of the emission nebulae, planetary nebulae and supernova remnants. Also, the out-of-band blocking ability is rated with OD3 (0.1%) with the blocking range of 200-1100nm. It delivers an excellent signal-to-noise ratio and a sharp cut-off rate to attenuate the disturbance from other wavelengths.

The narrow bandwidth and an effective cut-off rate are important features when choosing a narrowband filter. The Askar duo-band filter has a narrow bandwidth and an extreme transmission of over 90% at 500.7nm and over 80% at 656nm, whilst sufficiently suppressing other off-band wavelengths. So the Askar Duo-Band filter can efficiently reject all the light pollution. You can expect a terrific performance of this duo-band filter in artificially-brighten background sky with your astronomy cameras (like the ZWO ASI series color cameras).

(A note from Zoltan: the transmission curve suggests a very high value of nearly 98% for both parts of the spectrum, that is what we would expect from an Askar quality products ;o), so we asked the supplier to confirm if there was a mistake in the description as originally they stated 90%... They answered that it was just a mistake as the manufacturer's specification is min 95%, but the filters usually have an even higher resultant transmission.)

The production process is strictly controlled and every single Askar duo-band narrowband filter is individually examined and tested to ensure that they can highly satisfy the observing interests and needs of our customers.

Application

• Narrow bandwidth, properly designed for astrophotography both in light polluted or dark locations.
• Useful for imaging emission nebulae, planetary nebulae and supernova remnants.
• High transmission and sharp cut-off can greatly enhance the contrast and bring out the most detailed information for those deep-sky objects.
• Designed to sharply cut off the inference of artificial light from sodium vapor or mercury vapor street lights and other unwanted disturbance like sky glow.
• The Askar duo-band narrowband filter is not suitable for visual observation and not designed for imaging or observing the Sun.

ATTENTION! DO NOT USE THIS FILTER FOR OBSERVING THE SUN! SEVERE EYE DAMAGE MAY RESULT!