Tuesday, February 7, 2012


Its almost universally known that the easiest way to take high quality pictures of the moon or planets is using a small webcam.

The webcam is used to take a video which is essentially hundreds or thousands of individual pictures.  Computer programs like Registax look through all the individual pictures and pick out the highest quality images (the ones with the least atmospheric degradation, best focus, least movement) and stack those into one image. 

Although I've managed to get some nice pictures of Jupiter and Saturn this way it would be extremely difficult to get a complete image of the moon, particularly with any detail..  This is mostly due to the very small size of the image generated by the webcam.  The field of view is incredibly small; great for individual craters but impossible for the entire moon.

My previous post showed a high resolution image I am working on using Registax and my DSLR.  Instead of using a webcam I took about 100 shots of the moon on my DSLR and loaded them into Registax. At first this basically overwhelmed Registax and my computer's processing power.  Registax is designed to process pictures that are around 100 kb and I was loading pictures that were 18 Mb.  After a bit of fiddling around I found a way to get Registax to chug through them; there is a stacking option to use the minimum file sizes possible.  This isn't usually an issue when stacking tiny files from webcams but in this case it was an absolute necessity. If your using Registax version 6 its also a good idea to chose a small number of alignment points.  On a lunar shot you can get several thousand points but you really only need less than two dozen for decent alignment.  If you use the default alignment setting it will take forever to finish the alignment and stacking processes.

Even on my Quad-core desktop the processing took a while.  But once it was done I had one piece of my lunar mosaic.  Even with the wide field my DSLR gave me it only covered about 1/4 of the moon.  I repeated the imaging and stacking 4 more times and then had to stitch the final images together.

I accomplished this with the help of a great program called iMerge (although others have told me it can be done in Photoshop).

I'm still working on getting the colour better corrected and then I might restart the entire project with a barlow attached to get a slightly larger image.  It depends how long the post-processing takes.

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