NGC 1499 (California) with an OSC camera and dual band Ha/O3 filter

[old_eyes]

Two pane mosaic of NGC 1499 taken on Pier 5 @Roboscopes (Tak Epsilon 150, ASI 2400MC Pro, Askar Colour Magic Ha/O3 filter, unguided Paramount MX).

Upper pane 90 x 120 sec subs. Lower pane 63 x 120 sec subs (focus problems led to a significant number of rejected subs).

Processed in Pixinsight.

The O3 signal is weak in this image. Others have noted that if your O3 signal is strong and balances the Ha, a sual band filter with an OSC camera gives a good result. If the Ha is strong, then leakage into the green and blue channels can overwhelm the O3 signal. That is what seems to be happening here (OSC RGB Response and Dual Narrowband Filters - Experienced Deep Sky Imaging - Cloudy Nights).

Compare this result with a previous version done with a mono camera and narrowband filters:

Much better separation of Ha and O3 signals.

For this target the Ha/O3 filter gives a nice but less informative image.

Edited November 23, 2023 by old_eyes
Incorrect designation

[ollypenrice]

Nice result with good control of the bright and the faint, which are a long way apart in this target.

Olly

[old_eyes]

Roboscopes also have an O3/S2 filter on this pier. So I am trying that out to double the amount of O3 I have captured (lower QE for camera in the blue) as well as trying to add some sulphur signal.