De-rotate star images and stacking.





/SC3-Perseid-Registax-Rotate_95f-t.jpg

 12th August, 2005.  This is from the night of the Perseid meteor shower showing Cygnus and Lyra.

This first image is 95 frames stacked in Registax 3.  I have tried to use the Rotate tool but the effects are not what I was after.  I think I must have done something wrong as the frames did not de-rotate.

/SC3-Perseid-Drizzle-post-processing_95f-t.jpg

 12th August, 2005.  Again this is from the night of the Perseid meteor shower showing Cygnus and Lyra.

In this image you can see that the image was de-rotated as of the explanation below.


Here's how I do it.



open Envisage

 Start up the new Envisage V4 software.

If Drizzle is not selected then press the down arrow and choose Drizzle.

Add images to de-rotate

 Press the ADD button in the top left.   The standard Load screen will open up.  Browse to the directory where you stored the images. 
Highlight the first of the images you want to load in and de-rotate and stack.
Browse until you find the last of the images you want to de-rotate.  Hold down the left Shift Key and press the left button on the last image.  This will highlight all the images between the 2 clicks.
Now press Open.  Now your back to the start up screen.

Settings

 Click settings. 

This is where you can tell the program about you and your astro imaging equipment,  your site and imaging setup. 

It will also allow you to change where to store your images and dark frames etc.

Save Proc

 Open the  Save Proc and choose what format you want to save the image as then click OK.

Now your back to the start up screen.

Now give the image a name that you want to store it under in the top right in Object Name.


Start

 Now highlight the first image in the top left hand pane with the list of your images.
Press the down arrow key to go through the images and sort out the images you don't want to use.
When you find an image you don't want to include in the stack press the Delete on the left using the mouse
(I found the keyboard didn't work on this)
When all the images have been gone through and you are happy, again highlight the first image in the images to Drizzle/stack.

2 squares

 Now draw a square around 2 stars.  One on one side of the image and one on the other. I also make sure that Min Quality is 0 and the Evaluation Count is 1. 

This ensures that all images will be used.

Now press Start. 


Sit back and wait till its finished.

Move the Histogram sliders,  Auto Contrast and Shadow Enhance to taste.

Save the final image.

Load the image into favourite graphics package and tweak to get the best result.