Friday evening, early cause it was getting cold, I went out and was upgrading the learning curve of imaging by switching from the 20cm dobsonian (fl=1200mm) and a drift scan method to a 10cm Meade SC (fl=1000mm) equatorially mounted with a motor that does the RA tracking.
Jupiter was only 17 deg above the horizon at 19:00 EST and the more than half full moon was quite noticeable. What was noticeable was the -15C
But, once Jupiter was in the field of field with an eyepiece, it held centered quite well.
The asi120mc camera went in, replacing the eyepiece, and it took just a little while to get the focus, even with the superstiff focuser knob.
Surprisingly, the optimum exposure was still 5ms, same as with the much larger 20cm dobsonian..
letsee.. area=pi*r^2, MeadeSC would be pi*50^2=7850mm^2
the Skywatcher dob would be pi*200^2=125600mm^2
or x16 as much gross area.
You would think that would affect the exposure in some way!
In ay event, the image is not quite as big (1200mm vs 1000mm) but it is in the field of view much longer (still does drift a little).
I ran 5 sets of exposures, through out three, leaving two. Hey! I can still do arithmetic!
Viewing the raw .avi video (131MB), it looks horrible!
Ran them both through autostakkert! and one was better than the other.
Tested using 10%, 25%, 20%, 75% and 90% of the frames.
We can see a difference in the 10% from the rest. The rest look very similar.
This image comes from 4870 images (gross) and uses 75% of the frames.
So here it is, a 230×230 pixel 9KB image:
Can’t wait to step it even more with
1) a higher in the sky Jupiter
2) start with a x2 barlow
Love this camera!
even with the crappy old netbook (upgraded to 2GB RAM and a 60GB SSD) and a USB2 camera, it can capture near 192 frames/second, or 4800 in 25 seconds (actual exposure).