Tonight I aligned a brand sparkling old Celestron CGE equatorial mount, which I use temporarily, awaiting the arrival of my own 10 Micron 2000HPS mount. I have been waiting since 4 months now, but then, it has to cross the Alps, all the way from Italy. Not an easy task for any equatorial mount. Let alone it did not even leave the factory I learned the other day. Robtics in the Netherlands was so kind to offer me an interim CGE to be able to use my telescopes.
Anyway, using the drift alignment method, two hours were needed to get the Celestron aligned with the pole (where on earth does Celestron wants me to find the azimuth adjuster on this one). I like drift aligning, keeps you staring at a little dot in a cross hair eyepiece for ages. For non-astronomers: aligning an equatorial mount is the art of putting one axis exactly parallel with the earth axis. This way, one little motor can drive the mount so it makes one rotation in 24 hours, keeping the target in the field of view of the telescope, compensating for the earth rotation.
Seeing was pretty ok during the alignment process, turbulence well below average for Belgium. So, at least it would be a good night for Jupiter - I hoped. Well not exactly. When I turned the brand sparkling new Takahashi TOA150 refractor to the imaging target, seeing definitely had gone worse. Some good detail was visible on the monitor screen, but Jupiter behaved more often than not as a neurotic/elastic little ball of light. Definitely not a great start for the Takahashi planetary adventure.
Since the circumstances were not ideal to get into high resolution imaging, I compared two ASI cameras, the 120MM (monochrome) and the 120MC (direct color), being curious if the monochrome, using red, green and blue filters would teach the color camera (with Bayer grid) a lesson in grabbing detail on a planet. No sir, it did not. The color camera offered about the same resolution in the final image. So, when seeing is only average, you might as well save yourself the trouble of using a mono camera with filters. After all, direct color is a lot easier, and allows grabbing more frames in a shorter period of time. Would the mono camera without the Bayer grid overhead fare better in decent seeing? Likely. Especially if using derotation software like Winjupos to grab enough images in RGB. Will it be spectacularly different? I expect not. At least not most of the time and not in our country where moments of excellent seeing are very rare. One disadvantage of the color camera: due to the Bayer grid, it will never be ideal to use it with an IR pass filter, the most popular wavelength to compensate for bad seeing. There's no free lunch.
This was my best result of the evening. Nothing really special, but it was the first image of Jupiter with the TOA150.
Earlier that evening, Luc Debeck, a friend of mine, was using his 12 inch Orion Optics UK Newton for the first time. He used his 120MC camera under a tad better seeing. As you can see, the color camera works very well, just as good as the monochrome. The colors of my RGB image are more saturated, but that is a matter of taste and one click of a mouse away during processing. Let's give this comparison another try under better conditions and see what it gives.
On a technical note, when capturing video with the ASI 120MC, you may opt to record in raw format. If you are using Firecapture, switch off debayering while recording. You will be able to transfer more frames per second, as debayering does cause overhead on your recording PC. Stacking software like AS!2 can do the debayering later on in the process, and gives good color results. In AS!2 choose the 'force debayering GRBG' option for best results, under the Color menu.
Getting a nice picture not always requires these kind of titanic efforts, this one was taken with my iPhone, held against the telescopes eyepiece. Very hipstamatic.
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