Follow up from "strange happeings with jupiter" and "ring around jupiter

[1ponders] (Paul) · #1 27-02-2005, 07:27 PM

After taking a fine Jupiter avi on Saturday, the rest ended up like these two. I know we've been here before but I've adjusted the frame rate down to 10 and 5 fps, kept the exposure to around 1/25 and used a normal and reduced alignment selection area. Resolution for both was 352X288.

Any more suggestions. I haven't tried to push the processing and waveletting at all and used pretty much default registax 3 settings. Even using reference frames hasn't helped.

[1ponders] (Paul) · #2 27-02-2005, 07:28 PM

And the other one. Totally different outcome. Notice the rings.

iceman (Mike) · #3 27-02-2005, 09:19 PM

Can you zip up and upload one of the avi's? I just wonder whether it's something to do with an alignment frame choice or position, or some other setting.

If you used exactly the same capture settings, it has to be something to do with the processing..

bird (Anthony Wesley) · #4 27-02-2005, 09:20 PM

Paul, the first one looks like electronic noise - external interference maybe? Did you have the gain wound up a long way on that one?

The second image, I would have to say looks like too little gain or brightness , so there's not as many colour levels in the image as there should be. That's the classic cause of the "ring" effect, where there's only a small number of colour levels available due to a very dim image. But at least there's no interference noise either :-)

I have overhead powerlines in my backyard where I do most of my imaging, and I can sometimes get interference from them, linke diagonal lines running through the image,.

Bird

[1ponders] (Paul) · #5 27-02-2005, 10:14 PM

I'll Zip them and email them to you Mike if you can PM me an email. Won't be til tomorrow when I can access a faster upload.

If I remember correctly I captured the 1st one (the good one on the other post) on my meade outside and the rest on the C11. I remember I had all sorts of problems on the C11 trying to stop the image getting way over exposed so I had the gain way down, and the brighness. Normally I use quite a bit of gain (eg 40 up to 50) unfortunately I didn't record the settings as I was too busy fighting with the Losmandy mount getting the image centered and held there (actually finding the image first) I can't think of any electrical interferance. Apart from my laptop and the Observatory computer everything runs on 12V. Besides Saturn images I've taken there before have been fine. It only seems to be Jupiter I'm having problems with.

Now that I think about it at one stage I could see the checkerboard pattern in the live view and new straight off it would be a bad image. I've just checked the last settings on the laptop, gain 23, gamma 6 brightness 60, fps 5, exp 1/33. Maybe I just need to get Jupiter in a position at home so I can practice on it a bit more.

I'll try again next weekend hopefully and let you know how I go.

Cheers and thanks