View Full Version here: : Mars last night
multiweb
12-09-2020, 09:52 AM
Pointed the scope to Mars last night after a run on Jupiter and Saturn. It cleared my house and the trees around midnight. Gee it's tiny. :eyepop:
I had to barlow further. Good thing is it's bright so in 180s I can get over 10000 subs at ~90fps. Which I think is why I'm struggling getting details with Saturn. I can only do ~20fps and only end up with 2000 subs to stack best case scenario. Anyway here's a first process. Probably went a little hard on it? Processing feedback welcome. Need to learn all this stuff :thumbsup:
PS: Added animation here ~1.5h: http://www.astropic.net/astro/mars_anim.gif
Saturnine
12-09-2020, 02:22 PM
Hi Marc
That's quite an acceptable image, what was the seeing like at the time. Assuming you were using the 212 in CC mode, which camera did you use and a what focal length, frame rate seems slow for Mars, ROI setting has an effect on the frame rate. Hope I'm not stating the obvious.
Just as a comparison, I was out imaging Mars early this morning with a 150mm f8 newt, 2.5 Powermate and ZWO 290. With a RIO at 400 X 300 and a gain setting of 250 I was getting 180 Frames / sec .
multiweb
12-09-2020, 02:37 PM
Thanks Jeff. Nothing is obvious to me so lay it on :thumbsup: The seeing was coming and going from seeing features quite sharp at time to the whole disc bobbing about. I have about an hour of video in 3min chunks so will review other ser files. I started at 5.2m FL then increased to 7.2m afterwards. I can track really well at that FL so I capture a window cropped right around the disc at 90fps. I now realised that the IR filter is quite dark when doing flats so might try straight LUM next time see if I can increase frame rate and decrease gain. Camera is ASI120MM USB2.0 on latest FireCapture.
What do you think about processing? Ok or am I kidding myself and should dial it back? I get a little excited with the wavelet sliders. Probably coffee induced at 2:00am :lol:
Saturnine
12-09-2020, 05:09 PM
I don't really see any processing artifacts as such, the image is a bit soft but that is more likely the seeing. Are you governing the focal length by the oft quoted 5 X the pixel size, 7 metres does seem a bit much. 7000 div. by 212 gives a ratio of f33 !
Using an USB3 connection will help increase signal speed from camera to to computer. If the gear only supports USB2 then you are limited .With Wavelet Sharpening, generally I start with about 20% on all sliders and gradually increase to as much as 50%, but that usually starts producing artifacts so usually set around 25 / 30% range for the planets.
multiweb
12-09-2020, 05:18 PM
Cool, thanks Jeff. I'll try your recommendations for sharpening. At x2 I'm around f24 which roughly what's recommended for the camera just a bit above 5m. With Mars I thought it was a little small so I backed up the camera by another 50mm and refocused at 7m so I could fill the same surface as Saturn. That's the great thing with the FFC. The magnification alone is a function of the distance camera/glass. The focus point doesn't change much. Regarding USB3.0 unfortunately even my notebook doesn't even have USB3.0.
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