A ring around Jupiter

[[1ponders]]

While Saturn turned out ok, I have a similar problem to Gary. Jupiter was a bit low but the seeing wasn't too bad. After I'd processed the avi in Reg3 I noticed the corrector had fogged over a bit so that might have something to do with it.

I've really pushed the waveletting and other Reg processing to enhance the ring problem, so colour etc is way out. Any ideas anyone.

[Robby]

I have had similar problems in the past with Jupiter. Both Gary & I reckon it was something to do with stacking, & registax not getting a good "register" point..
When we had a lunar shadow on the image the stacking seemed to work heaps better as you could register on the shadow.
I don't know if this is the problem here, but's it's something to think about. Wait a couple of months and then Jupiter will be much more socialble.

Cheers

[[1ponders]]

It could be. I've also been thinking that where the first ring starts is also about where the brightness starts to drop off as well. I was using a moderate gain and quite a bit of brightness. Though I tried twice in registax with different filtering parameters. I used default as registax chose it (FFT 3 and Quality 5 and 50) the first time and I upped the FFT filter to abut 9 or 10,and set the quality filter at around 4 and reduced the with to about 15 the second time. Didn't make a great deal of difference though. So I guess its something to work on.

I'll keep an eye on Jupiter for a transit and try your idea next time.

[gbeal]

Paul,
the thought around here is overcooking the waveletting, and with poor seeing there is little else that you can do. My shot had poorish seeing, so really I can only hope for better next time to dispell this.
I had zero gain, and about 50% brightness, with 1/33rd sec shutter speed, and about 70% gamma, ( I think).
Sound similar to you, (you have got WcCtrl?).
Gary

[rumples riot]

Hi Guys, I heard that ringing is caused by under exposure. Gary if you shutter speed was 1/33rd you probably were underexposing. Sorry I know I have been at this less than you, but I have spent a great deal of time reading up and this seems to be the popular opinion. I have personally confirmed this with some experiments that I conducted in this regard.

Anyway just my opinion.

[[1ponders]]

Yes I do have WcCrtl Gary, I like it very much.

The ring is there even before waveletting. I've only pushed to make it more obvious. I think my exp was 1/33 as well. I use next to no gamma, this one had around 80% saturation, and I like to use a bit of gain, often up to 50 or 60%.

I'll take a shortish (about up to about 60 sec) avi then process it roughly on the spot to see how the settings are working out on the night. Then get intouch with my sensitive side and see how I feel I should adjust them. Very new age scientific. :P If a setting works out well I save the settings in WcCtrl for later use. Takes some of the guess work out of it.

[gbeal]

Rumples,
don't apologise, and nor should you think that you know less than me, far from it, I am still very much a beginner.
I will try your thoughts next time, and while I can only drop to 1/25th I CAN up the gain etc. The image on the laptop screen was bright enough, well it was when the clouds weren't in the road.
I need to practice this more, so when that perfect night appears I will be set. Thanks

[iceman]

I've found at most times, 1/25s is too long for jupiter, even with 0 gain. My image is usually completely washed out. I usually go for 1/50s on jupiter to get the colour right.

My thoughts on the ring would've been too much processing, but if it's there before, it must be something else.

[bird]

My favourite $0.02 theory is that it's a combination of intensity gradients near the limb and registax locking onto those gradients as a "feature" to be tracked & stacked, making them stand out and as a side effect blurring the "real" features that you wish Registax would use instead.

Maybe try a smaller alignment box in registax that covers only the inner part of teh disk, and exclude the troublesome area.

Bird

[iceman]

Hey that's what I do with Jupiter! I use the 32 alignment box (I think, maybe it's 64) with my image scale, and the square neatly fits inside each edge of jupiter with the corners of the square touching the outside of the planet.

[[1ponders]]

Right, thanks Bird and Mike. I'll definately give that a go. I tend to use an alignment box that will just fit the image inside. I'll reprocess and repost so we can compare.