Well, no second sketch tonight, seeing deteriorated even though mars climbed another 10°, the view at cm 74° is similar enough to cm 82° last monday to pack things in and go to bed.
Kris, yes, take advantage of the opportunities. For mediocre seeing, you did very well getting your observing eye in gear. That's what it's all about. I also notice some apparent differences in color of Mars. One night it looked more yellowish to me, then next it was more distinctly orange. Must be the atmosphere. Great observation for a large aperture in mediocre seeing. I think that speaks to the benefit of aperture and a keen eye.
Absytec, this makes me wonder: Is it something of a rule of thumb that under mediocre or poor seeing smaller apertures tend to perform better? If so, I tend to not disagree:
I've only ever used an 8" f/5 dob from around 2000 untill 2009, then I got me a 12" f/5 dob in search for extra aperture to improve my planetary viewing.
The 12" is the workhorse and the 8" doesn't get used anymore. however I was not blown away with what the extra 50% aperture increase brought, I expected more of it. sure the image is a lot brighter, which supports higher magnification, but as seeing is usually mediocre over here I mostly observe planets at around 300x and rarely push to 400x or let alone 500x (I think i've only once or twice went around or above 500x in almost 2 decades!).
So I get the impression that the 12" only surpasses the 8" and excels when the seeing is really, really good.
Looking back at my Mars sketches from 2005 and 2007/08, they don't show a lot less detail than the following oppositions from 2009/10, 2011/12, 2013/14 and the few sketches from 2016 & 2018.
Given the extra hassle to set up the 12" instead of the smaller 8", I maybe should go back to the 8" which I can also mount on an EQ platform, and break out the 12" when the seeing is outstanding?!
Edited by Kris., 22 October 2020 - 06:20 PM.