From: "Milton Aupperle" <milton@outcastsoft.com>

Date: July 24, 2006 9:06:29 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: stacking and histogram questions

Hi Eric;

I'm on vacation, communicating via a 2600 baud modem, so getting

e-mails is a major pita.

Astro IIDC will reject frames if they exceed the matching tolerance

that you specify. Even if you pick 0% (ie all frames) of the

histogram, it may still reject frames that simply don't match based on

your tolerance setting.

Part of the issue sounds like you have your gains cranked all the way

up. So when it trys to match up one frame against another it may wind

up just matching noise for low contrast areas.

I'm working on changes to selectively allow smoothing of the images

before doing sharpness and alignment (likely a 1 or 1.5 pixel radius

gaussian blur) which should drop the noise level a lot and remove the

noise.

HTH..

Milton Aupperle

--- In Astro_IIDC@yahoogroups.com, "Eric" <eddot1103a@...> wrote:

Hi,

During my laborious processing of various streams, I notice that

IIDC sometimes doesn't stack all of the frames I originally picked. 

This has happened for both lunar and planetary sessions.  I noticed

with Jupiter that I had to prealign in KIS first before IIDC would

accept all of my hand picked frames.  With the moon, if I try

prealigning first, in IIDC it doesn't align them well at all

presumably because KIS allows the black edges to remain if it realigns

a frame.  Is there anything I can do in IIDC to get all hand picked

frames stacked?  I've had confidence at 0 (because they are hand

picked) and I have tried various matching, but still a certain number

of frames are excluded.  

I'd appreciate any histogram suggestions.  Maybe because my monitor

was incorrectly adjusted, not sure, but a lot of what I captured

recently came out with very low gains, to the point where I have to

significantly adjust the histogram of the final stack.  During

capture, I had the histogram enabled and adjusted gain until the curve

was "pure" without jagged lines.  If I continued to increase gain, I

would get a jagged histogram but not saturated.  Can I risk running

the gain where the histogram shows jagged lines and what do the jagged

lines (within the histogram curve itself) indicate?  Not talking about

saturation here, just an "impure" looking histogram during capture.  

Sorry for the long questions, but appreciate in advance any

suggestions for the above.  

Thanks,

Eric