On the night of October 18, 2020 I captured a series of images of Mars using my standard imaging setup and a new setup incorporating a filter wheel intended for capturing images with a mono camera to generate RGB images. Below is a comparison of the plate scale, Focal length, and F number for the different configurations (theoretically, ~F/19 is ideal for the 224MC and ~F/15 is ideal for the 290MM):

Setup Camera arcsec/pixel FL (mm) F#

Setup #1 224MC 0.18 3319 17

Setup #1 290MM 0.135 4425 22

Setup #2 224MC 0.215 2779 14

Setup #2 290MM 0.165 3621 18

The original setup (Setup #1 in this comparison) that I worked out for the Mars apparition in 2018 gives ~0.18 arcsec/pixel (~F/17) with an ASI224MC and has the following imaging train: C8/Meade Flip Mirror/Siebert 2x custom barlow (filter sized, here attached to a ZWO nosepiece threaded on to the ADC), ZWO ADC (with standard end pieces removed)/T2 rotator/Filter (attached to ZWO camera using a T2 to 1.25" filter adapter)/ASI224MC attached to the T2 rotator using and ZWO T2 to T2 adapter. I'm pretty happy with the results I get with the 224MC in this setup. I tried the ASI290MM in this setup (manually swapping filters in the 290MM from channel to channel) but the results were pretty unsatisfactory at F/22 with the ideal setup for the 290MM being in at F/15.

The new setup (Setup #2 variations) that incorporates a filter wheel and gives ~0.165 arcsec/pixel (~F/18) with an ASI290MM and has the following imaging train: C8/Meade Flip Mirror/ZWO Filter wheel + filter/T2 rotator/Siebert 2x custom barlow (filter sized, here attached to the ADC using a 1.25" to T2 adapter)/ZWO ADC (with standard end pieces removed, attached to the T2 rotators on both sides using T2 to T2 adapters)/T2 rotator/ASI290MM attached to the T2 rotator using and ZWO T2 to T2 adapter. I tried the ASI224MC in this setup (image labeled Setup #2B) which comes in at ~0.2 arcsec/pixel, but I feel like the result with the 224MC at F/14 in this new setup is inferior to the original setup #1.

At the end of the day, I was hoping to have one standard setup to use with both cameras, but unfortunately that didn't work out (to my satisfaction at least). The original setup is giving good results with the 224MC, but is pushing the 290MM to too high an F# (and with my typical seeing conditions the F# really should be lower than ideal to take advantage of faster captures without losing any detail that seeing is obliterating anyhow). The new setup looks really good for the 290MM, but is too undersampled for the 224MC. At the end of the day, the RGB image generated by the mono camera has the edge on the OSC camera result, but there is a lot more work involved. My plan is to stick with the original setup for typical imaging sessions since I am happy with the results, and generating images with the OSC camera is a lot quicker to capture and process. For nights of exceptional seeing, the extra work associated with the new filter wheel + mono camera setup justifies the extra capture and processing work.