Two pane mosaic of NGC 1499 from Pier 5 using OSC camera and Ha/O3 filter (NGC1499_final_resize.jpg). From Jobs 2373 and 2374.
90 subs from 2373, but only 63 from 2374 due to a focus problem.
All processed in Pixinsight.
The image shows a small amount of O3, but not as much as might be hoped.
Others have noted that if your O3 signal is strong and balances the Ha, a dual 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 (NGC1499.jpg).