Cyclops Optics, of Hong Kong, has launched the STC Astro Duo-Narrowband filter. This filter passes two critical 10nm narrowband lines Hydrogen-alpha and Oxygen-III simulateneously at a very high transmission rate, enabling narrowband imaging with one-shot-colour (OSC) camera and DSLR with high efficiencies even under heavily light polluted sky (according to their info). Available in 48mm and Clip-in versions, at $329 USD with free International shipping,
For all the info click on the product description link on the page below.
https://www.cyclopsoptics.com/astron...7-8bbc10b55357