Jupiter in bad seeing

[iceman (Mike)]

I shouldn't have even bothered imaging because the seeing was really bad (about 3/10), but I wanted to try out the 2.4x barlow I'm borrowing from Gary Beal.

Plus, the GRS was transitting and I was hoping there might be the odd moment of good seeing to get an ok image.

Wasn't to be, the images turned out pretty crap.. I did notice the larger image scale with the 2.4x barlow (as opposed to the 2x that I normally use), the planet drifted across the FOV in about 9-10 seconds, instead of around 12 seconds. It was really hard to get focus right, as even on a star with the hartman mask, the image just wobbled about so much it was "best guess" focussing.

I notice some colour differences in the 2.4x barlow compared to my normal 2x, I eventually got it looking sort of natural, but I had to reduce the saturation to halfway, when normally I have it near full.

The smaller image is at prime focus, just to try and getting something a little crisper cause the seeing really couldn't handle high magnification.

The larger image was with the 2.4x barlow, pulled out of the focuser and the ToUcam pulled out of the barlow. At normal 2.4x it would be 3000mm FL, so with them both pulled out, maybe another 20-30mm @ 3030mm FL. The small image is @ 1250mm FL.

Not happy with the nights efforts, but I only spent 30 minutes out there after Desperate Housewives was over so it's not as if I wasted hours for this shocking image

- 10" dob + ToUcam
- 2.4x barlow for the large, prime for the small
- 1/33s exposure for the large, 1/250s for the small
- Low gain for the large, 0 gain for the small
- Saturation 50% of the large, 95% for the small
- Large image stacked around 40/150, small 90/700.

[gbeal]

Hi Mike,
well I thought I was the only one suffering piss poor seeing, but no. I also got an e mail from Robby with the same complaint, so we are all in the same boat.
I too was out with high expectations, and was disappointed too. Rob sent me his and I will leave him to post it, mine is attached. Taken about an hour earlier than your perhaps. Tak Mewlon, @f30 (2.5x Powermate), 526/655 frames.
Gary

[[1ponders] (Paul)]

Still having problem with the onion rings Gary?

[toetoe (Peter)]

I like the pics, they are good compared to what i see with my little scope.

[Robby]

And he's my effort. A little late than Gary's but no better seeing.
C9.25 at f/25 (2.5x powermate)
Cheers

[[1ponders] (Paul)]

I think we need to call that one "Monet's Jupiter" Robby. Lovbely pastel shades. there must be a bad "seeing" cell over most of Australia and NZ at the moment.

[Striker (Tony)]

What causes that edge affect on Gary's picture.....I still think the picture looks pretty good but the edge really stands out to me as soon as I look at it....

[ving (David)]

oh i dont know, they look ok to me!

[5ash (Philip)]

heres my offering for the night of the 18th april . still playing with the processing. seeing woud have been better if i'd remembered to turn the observatory roof round to track my subjects.
philip

[[1ponders] (Paul)]

that's the infamous "Onion Ring Effect" Tony. You can just make it out on Robby's image as well and very faintly on 5ash's

[gbeal]

Paul,
in my earlier days (heck I am sounding old) of ToUcamming I used to suffer severe Onion Ringing. I always understood this to be another "line" or two on the image.
What Tony is talking about is the sharp edge of the limb, rather than a faded off edge. If I drop the gamma this fades well, but to me when I look visually the edge is hard and sharp, and this is also rendered in my shot.
Are you saying that this "Onion Ring" is when I have a hard sharp edge on the limb? Help an old timer out here.

[[1ponders] (Paul)]

Probably my misunderstanding Gary. I was talking about the ripple effect (extra wavy lines) away from the limbs of the planet.