Frank,
I see that my SeeStar automatically used the Light Pollution (LP) filter. M42 is a gaseous nebula and does respond well to a narrowband' filter. In advanced setups narrowband filters typically let in only 6 nanometers (nm) of light at a specific wavelength. That's what Dave used with his Hydrogen Alpha (Ha) image of M33. That explains why his exposure was 450 seconds long, but also he has a CCD camera whereas you have CMOS. Yours requires shorter exposures.
The LP filter on the SeeStar passes approximately 40nm combined light of Ha and Double-Ionized Oxygen (OIII). It won't have the crispness of a dedicated mono camera with a single-wavelength narrowband filter, but you'll like the results and cost is reasonable.
I have several filters for my mono camera, but I recently bought an Antlia tri-band filter for the SeeStar.
This link is for a 2-inch filter but you should make sure it fits your filter holder:
https://agenaastro.com/antlia-triband-r ... unted.html
A tri-band filter yields better star color due to the blue band. Dual-band filters only given you the Red and Green at Ha and OIII. The difference is important since you have a color camera. The total bandpass is 80nm compared to 300nm with a conventional IR/UV filter. You will have to expose longer, perhaps 20 seconds instead of 5 seconds.
Brian
