The technique shows you how to capture video of a celestial object using a low light webcam, such as the Philips TouCam Pro II, then process the video to give a single, good quality image.

You can use the software supplied with the webcam to capture the video or use  third party video capture software like K3ccdTools, the captured video must be a .avl file to work with the image processing software, RegiStax Version 4.

Paul has written a guide to using K3ccdTools 3 to capture the video from the webcam. 

Basic guide to webcam imaging in K3CCD TOOLS   -   By Paul Cheesman

1) Turn on your laptop or pc and connect your webcam

2) Once connected open up the k3ccd tools program

3) If your webcam is not automatically recognized click on the device tab at the top of the screen. From there check the video for windows tab, then the webcam should appear in the bottom of the box (it may appear as ‘Microsoft WDM image capture`) make sure this is checked then your webcam should have been recognized.

 

4) If once connected you have no preview screen, click on the video capture tab (next to the device tab at the top of the screen) and click on the preview tab. in this box you will also see a show level meter tab, click on this and it will put a light meter on the side of the preview screen which will help when centering and focusing the objects

5) Once you have a preview on screen, you then need to click the video capture tab again then click on video source, this will then open up the control panel of the webcam where you can adjust the webcam settings such as shutter speed, frame rate, white balance, brightness and contrast etc (but firstly you must uncheck the full automatic control box)

6) Once you have adjusted the image too your liking close down the video source box by clicking the OK tab (this saves your settings) you are now ready to start capturing your image.

7) To start capturing your image you need to click the capture a video sequence tab, before you do this click on the reticule tab and this will put a red reticule on the screen as this will aid you in getting the object dead center of you screen, you will then see a live image replace the preview screen on your laptop/pc screen

Once centered you are ready to start.

8) To finish taking your video sequence (AVI) simply right click on your mouse and the webcam will stop capturing an image

9) Now you have captured your image it is now ready for processing. this can also be done in k3ccd tools which is very good, but on a personal view RegiStax seems far more simple to use for a newcomer to imaging.

This is a basic guide to webcam imaging with a Philips webcam, other webcam manufacturers software may be different but will still work in the same way in k3ccd tools

Click here to download the K3ccdTools instructions

Dave Paulding has written a guide to using RegiStax.

A Basic Guide to Using

RegiStax 4

For processing astronomical images from webcam video

Overview
RegiStax is a great free astronomical image processing program, from Cor Berrevoets (The Netherlands), that allows you to align and stack many single images of treat video files as a series of single images for alignment and stacking, this guide will concentrate on the video processing aspect of RegiStax. It can automatically take the highest quality images from a frame list align and combine them to give a final image that can be manually tweaked to give an impressive end result you can be proud of. The program is brimming with options and advanced features but you can use the default settings for most of them to start out with, you can experiment and learn how to use the programs features over time to tweak your images and get even better results.

RegiStax is not an image capture program so you will need to use either the video capture software that comes with your webcam/video camera, or use third party video capture software like the K3CCD Tools package. RegiStax produces the best results from short videos taken through a driven equatorially mounted telescope that tracks the target object, you can manually track your target with an un-driven telescope, but it becomes more difficult to keep the target centred in the field of view as time passes. If you are using an Alt/Az mounted telescope, you should keep the video a short as possible as the field of view will rotate over time and RegiStax can not align frames that are rotated with respect to each other.

Supported import file types

Still images:

• .bmp
• .fit
• .jpg
• .tif
• .png
• .ser

Video:

•   .avi

  

Output image file types

•   .bmp
•   .jpg
•   .fit
•   .tiff
•   .png

Starting Out, File Selection
Once you have started RegiStax you are faced with a somewhat daunting screen with numerous buttons and tick boxes in a control panel, as this is a basic guide we will be ignoring most of these and using their default values, where changes are needed, there will be clear instructions.

You need to select the video file that you want to process, this is done by clicking on the ‘Select’ button on the top left.

This will bring up a dialogue box, in which you can navigate to, and select your .avi video file.

When you have found and selected the desired file, click on ‘Open’ and the video is imported into RegiStax ready to be processed, you will see it appear in the main part of the screen below the control panel. It may appear rather small, but you can use tick the ‘View Full Image’ box (1) to see it larger.

Selecting Alignment Points
To allow the automatic alignment process, the program needs to have a reference point to work from, select the size, of the reference box that will be placed on the image, in the ‘Alignmentboxsize’ tick boxes (2), sizes are in pixels, this should cover the entire feature that you want to use but not be so large that it goes off of the side of the image, the point will not be used if it does. You now have a couple of choices, you can select single point or multipoint alignment in the ‘Method’ tick boxes (3), note that single point alignment will process quicker that multipoint as the alignment process runs once for each point, it’s best to start off with single point alignment.

Single point alignment:
Find a prominent feature on the image for the program to use as a reference point. Move the mouse over the point that you want to use and click, a box will appear on the image, a couple of other boxes will appear but they are for information only, so ignore them for now.

 
Multipoint alignment:
This method of alignment uses multiple points as references to ensure that all parts covered will be aligned in the final image, fortunately RegiStax can pick these points automatically for you, click the ‘Multipoint’ tick box under ‘Method’ (3), a new box will appear, click on the ‘Estimate best alignment points’ (4) and a series of alignment boxes will be placed on you image.

 

Image Quality Selection
Now you need to decide on the lowest quality of the image frames that will be selected to be stacked to make the final image, just to the right of centre in the control panel, the Gradient method should be selected in the ‘Quality Estimator Method’ dropdown box (5), if it isn’t then select it. In the box below (6) you can select the ‘Lowest quality’ of the frame image that will make it into the stack, RegiStax will assign a quality, percentage, to each frame image, in the example below only images that are of quality 90% will make it in to the stack. If the original video contains very little scintillation then the ‘Lowest quality’ can be set low but video that moves and shimmers will need the ‘Lowest quality’ set high, use the up/down buttons to change the setting, 85% would be a good place to start.

General Options Settings and starting processing
On the lower edge of the control panel are some tabs that will change the controls that you see, there are a couple of final setting to make before processing. Click on the ‘General Options’ (7) tab and under ‘Tracking settings’ select ticks for ‘Track object’ (8) and ‘Ignore misaligned frames’ (9), this just drops misaligned frames from the stack. Select ‘Automatic processing’ (10) to run through the ‘optimise’ and ‘stack’ processes without the need for you to do anything.

 

To start the processing sequence, click on the ‘Align’ button (11), the progress of the alignment is shown in a small window giving the estimated time to completion. When the alignment and processing is complete, RegiStax will open the ‘Wavelet’ tab showing the aligned, optimised and stacked frame as a single image.

Riding the Wavelets

In wavelet screen the image may be a bit small so you can click the ‘Show full image’ (12) tick box to make it bigger. At this stage the brightness of the image may make it difficult for you to see details on the image, you can adjust the by clicking on the ‘Contrast/Brightness’ tab (13) to show their control sliders (14) and up/down control buttons, make small adjustments to these until you have the optimum settings to see what detail you currently have in the image. If you think that your adjustments have made the image worse and can’t seem to correct it, there is a ‘Reset’ button on the right-hand side of the slider, which will remove any adjustments that you made.

The wavelets control panel on the left side allows you to make adjustments to the sharpness of the image, select the ‘Default wavelet filter’ (15) and make small adjustments to the horizontal sliders (16) until you have the best detail in you image, this part is trial and error and you may have to sacrifice some detail for less pixelation, again there is a ‘Reset’ button (17) if it all goes wrong, when you are satisfied with the results, click on the ‘Do All’ button (18) to apply them to the image.

 

The Finale

The last couple of adjustments to be made are found under the ‘Final’ tab (19), in this tab the controls allow you to rotate the image, use the rotator dial, up/down buttons or presets in the dropdown list to select the angle of rotation (20), there is also the option to flip the image in the x and y axis.

There are colour adjustment controls (21), moving the ‘Hue’ slider, left makes the image redder, right makes it bluer, the ‘Saturation’ slider makes the colour weaker to the left or stronger to the right and the ‘lightness’ slider adjusts the brightness.


Saving Your Image
And when you have completed your adjustments and you have the image just right, click on the ‘Save Image’ button (22) to bring up the ‘Save As…’ dialogue box. Navigate to the location where you want to save the file in the usual way, type the file name into the file name box, select a supported file type from the dropdown box below that and click on the ‘Save’ button. You can repeat the saving process if you want different file types of the completed image.

 

 Click here to download the RegiStax 4 instructions