PixInsight Forum (historical)

PixInsight => Image Processing Challenges => Topic started by: Luigi on 2012 May 04 13:52:34

Title: Plea for help -- too much noise or lack of know-how?
Post by: Luigi on 2012 May 04 13:52:34

Here is an RGB 'master' for an M81 I'm working on. But I'm perplexed because I thought I had enough data, but it seems I never do  :(

So, I've put the RGB frame (still linear) up on DropBox hoping to get some help with this.
http://dl.dropbox.com/u/21911242/M81_RGB.fit

This is 17x5min exposures in each 'color' plus some shorter exposures to 'debloom.' I converted the 64-bit to 32-bit to save some file size.

When I try to get the noise under control (MMT) I am not please with the results (this is to be part of an LRGB image). So, it's either not enough (or poor) data, or, I don't know what I'm doing. I'm leaning slightly toward the latter but would appreciate some learned opinions.

Title: Re: Plea for help -- too much noise or lack of know-how?
Post by: TeeJay on 2012 May 04 14:24:07

Hello Louis,

the color information in the date are very nice, there's a lot information from the H-II regions. But you have some very strange noise. Which camera did you use? How did you realize the "deblooming with shorte exposures"? I think the error is perhapse there... How does your Luminance looks like? Because if you have a "noise-free" Luminance, the Noise in this RGB is irrelevant.

CS
TeeJay

Title: Re: Plea for help -- too much noise or lack of know-how?
Post by: Luigi on 2012 May 05 06:29:50

TeeJay,

Camera used is SBIG ST-10XME.

The 'long' subframes are 300s; I used HDR composition with 90s exposures.

I will post up the luminance master shortly.  I don't have access to the data right now.

Thanks for taking a look!