Strange happenings with Jupiter on Saturday

[1ponders] (Paul) · #1 06-02-2005, 08:53 PM

It finally cleared on Saturday night so I thought I'd give Jupiter a shot. It was early in the night (around 11:00 to 12:30ish) so the seeing was moderate to poor. I saw Io popping out from behind Jupiter and decided to try to catch it on video. I had the saturation and gain set fairly high so the images are very yellowy-green. Strange thing though is that all exept 1 of the videos when processed end up with checkerboard patterns over them. (See second set of images) The right one in the first set here had it as well but I managed to remove nearly all of it.

Can anyone explain why this might have happened. Unfortunately as it was a spur of the moment decision, I didn't write down the settings I used. I used K3CCD to capture, WcCtrl to adjust settings, Registax 3 to stack and Photoshop for final adjustments. The checkerboard was there after waveletting in Reg3. I do remember that I'd set the gamma around 10 - 15 and the fps were fairly high I think ( more than 25fps). Would either of these cause this effect?

[1ponders] (Paul) · #2 06-02-2005, 08:54 PM

The first of the "funny" ones. This is a before waveletting and after

[1ponders] (Paul) · #3 06-02-2005, 08:56 PM

And the second set. Produced from two different avies

iceman (Mike) · #4 07-02-2005, 05:55 AM

I'm pretty sure it's your registax settings.

I've seen this on some of my own images after trying to do "resample" or "drizzle" from the optimise page.

Try re-doing the avi's in registax without those 2 options and see if it still occurs. Alternatively, zip up one of your avi's and upload it somewhere for me, and i'll try and process it and see if I get teh same problem.

btw they'll be great looking shots when you've sorted out this problem!!!

gbeal · #5 07-02-2005, 06:07 AM

Paul,
not entirely sure, but to me they look like processing artifacts as well. Perhaps less waveletting? The raw(s) do indeed look good.
Gary

iceman (Mike) · #6 07-02-2005, 06:09 AM

Quote:

and the fps were fairly high I think ( more than 25fps).

This could also be a cause. With the ToUcam, higher FPS means more compression to try and fit the data down the USB 1 interface.
When seeing is great, you should use 5 FPS so there's little to no compression of your original AVI by the capture software.

If you're using 25 or 30 FPS, the compression might be causing loss of detail and therefore less room to adjust the wavelets.

ving (David) · #7 07-02-2005, 09:12 AM

I have nfi, but nice moonage

[1ponders] (Paul) · #8 07-02-2005, 09:54 AM

I have a feeling it might be right about the fps Mike, I thought I
c check whether anyone else had experienced it.

Mike I don't use drizzling and resampling, so its not that (don't even know what it is, though I've noticed the checkboxes). Gary if you look closely at the second set of images the raw avi stack already shows the tessellations. Waveletting only made it worse.

As I mentioned seeing certainly wasn't good so I was trying to capture very short exposure images, hence high gain, short exposure and fast fps. Not a good combination by the look of it, though I'm sure the artistic amongst us could put it to stunning effect.