About this product
Part Number: 2 Duo-Band
The Askar Duo-band narrowband 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 performs well with ordinary colour cameras. So the duo-band filter is an economical alternative for astrophotographers whom prefer to use a colour imaging camera and wish to enter the world of narrowband deep-sky 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 centre 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. The Askar duo-band filter can bring out the highest amount of detail within 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 high performance from this duo-band filter in artificially-brightened background skies with one shot colour CMOS and CCD Cameras.
|Average Rating (1 Review): |
06 January 2023 | Graeme
Managed to get out and test this filter bit long after it (very quickly) arrived. On paper it appears to be a good competitor to the L-Extreme, both being 7nm in Oiii and Ha, although I'm aware the L-Extreme has issues with halos at times. Did a couple of test hours with the Askar on the Jellyfish Nebula and the Heart Nebula during an 80% moon. I had no halos, and the blocking abilities were fabulous. Would actually recommend this over the L-Extreme, especially as it's cheaper!
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