From: Milton Aupperle <milton@outcastsoft.com>

Date: March 7, 2009 10:14:09 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] More New Lunar Images..

Hi Mark;

A few other suggestions from your log:

1) Don't set the pixel matching value (i.e. "Allow up to xxx.x variance per pixel when matching pixel areas")  to 0 or all you will probably get is one frame stacked, which is what happened.  As I suggested in the manual, use a value in the range of 5 to 8 (see page 31 of the manual). I am using 6 for these lunar images I'm posting here.

2) Don't use Luma option for  "Use XXXX color channel for sharpness and alignment" when stacking, the answer why is on page 28 of the manual.

3) Use an appropriate Gross alignment method (i.e Lunar/Solar or Planetary) for your target. The log you showed me was set to planetary, but I think you were processing Lunar movies? This also affect the Sharpness estimates and histogram as we use a different method for estimating sharpness for Lunar/Solar than we do for Planetary.

4) Unless you had clouds causing the brightness to change AND a perfectly polar aligned mount, don't use "Adjust pixel area brightness if frame brightness changes." for lunar imaging. See page 32 for more info on this.

5) The only reason you should be using "Gaussian blur the frames used for sharpness estimation & alignment" option is if you used really high "Brightness" slider values on the camera controls. High Brightness amplifies CCD noise and this will reduce it. Since you were shooting the moon with a focal reducer, you likely had Brightness set very low.

As far as DSO object exposure times, it varies based on the object and the only way to find suitable exposures is trial and error. Once you've done a few brighter objects it will make more sense. And don't bother going after Mag 16 galaxies the first night, pick a nice bright open cluster or M42 or whatever is conveniently high in the sky and get used to simple stuff before going "deep".

Hope that helps..

Milton Aupperle

On 7-Mar-09, at 9:35 PM, Mark Gaffney wrote:

Hi Milton you like that "DomeZilla" region don`t you!! I guess you

mean the RGB saturation box? The images were that colour when taken-

perhaps not light enough, although I thought I was already being

gentle with the colour! If what you`re saying about your originals is

right they`re more grey than brown to my eye- must be a very light on

approach! You`re right I`ve got the "Sharpen the frames used for pixel

alignment" box & the "Sharpen frames by (High) amount before stacking

them" selected. I missed that bit about it needing to be very light.