From: "centurion40tim" <centurion@cableone.net>

Date: September 28, 2010 9:56:23 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Hoping to get a baseline for post-processing

Good info. Thanks. I posted jupiter.grs.ganymede tonight. Not my best effort but the first time I've shot a shadow event where you could see the moon casting it. The missing brown band helps the grs stand out a little. 

Would like to use Astro IIDC to process and export a high quality reference movie from a file of 4000 - 5000 frames. Obviously that's too many frames to work with individually. But I could manage less than a hundred frames or so. Then I figure I could split it out, snag and stack the truly outstanding frames. I am running version 3. something. Is this feature available in newer versions of Astro? I've seen others talk about it.

thx TimH in Arizona

--- In Astro_IIDC@yahoogroups.com, Milton Aupperle <milton@...> wrote:

Hi Tim;

On 25-Sep-10, at 3:12 PM, centurion40tim wrote:

Jim and others:

Since no one else chimed in, I'll take a stab at it.

It's been a while since I've shot a planet. I dusted off my old iMac  

and dug out my Unibrain. It was great to get out and shoot Jupiter  

again. The only problem was seeing was terrible. I believe I have  

the data I need, however, to get a decent pic out of these sets.  

Each set is about 4000 frames. Need a little help with AstroII DC's  

post processing tools. Specifically I need a baseline from which to  

proceed and/or any advice I can get:

a) I used both horizontal and vertical areas for fine alignment.  

Right?

I normally hand pick a area manually if there is any detail to be  

seen. From what you said about seeing being bad, it likely will make  

little difference.

b) What size area for comparison should I start with?

That depend son what Focal length you shot it at and if your scaling  

frames, but likely 64x64 for Jupiter at 2 to 3 meter focal lengths. If  

you used a long focal length where the limb is basically straight,  

then you need to use a bigger area to include some curvature to make  

the area "Unique".  See page 54 of the Astro IIDC manually for some  

explanation on what I'm talking about.

c) To what degree would the matching be when comparing pixels?

As long as you did not crank the crap out of the gains / brightness to  

add a lot of image noise 8 to 10 is usually a good choice.

d) Should I scale frames?

That has to be decided on a case by case basis. I normally use that to  

suppress noise and provide better alignment.

If you do use it, don't forget to increase the Pixel Area size  

comparison appropriately too.

e) Should I use Gaussian blur for estimation before stacking

Only use it if you have a lot of noise in the image from high gains.

f) Should I sharpen frames before I stack?

Since you mentioned it was a really bad turbulence night, probably  

not. There is likely nothing "sharp" to sharpen.

HTH..

Milton Aupperle