Imaging Techniques

I'm no master astro-imager, but I'm getting better with experience and feedback from others.  With good friends like Don Goldman and Ken Crawford nearby, it is much easier to gain the knowledge that makes for improved imaging and processing.  My plan is to present a general view of my workflow here, with links to more detailed procedures as described by some of the best astro-imagers. 

Astro imaging starts with planning.  I get ideas for subjects from friends, the internet, and browsing in books and software.  One of my favorite books to browse is Hans Vehrenberg's amazing collection of four-degree-square wide-field images made on film with a classic Schmidt camera ("Atlas of Deep-Sky Splendors", Sky Publishing).  His images are very helpful for finding subjects and planning framing.  I also browse the skies using "SkyTools2" by Cappella Software and "The Sky6" by Software Bisque.  The Sky also controls my mounts for imaging, locating objects and assisting in guiding and astrometric analysis. 

Imaging uses a number of tools.  While The Sky is the primary control program, it is supplemented by TPoint and AutoMapper II to refine the polar alignment, pointing and guiding capabilities of the Paramount ME German-equatorial mount.  Further automation of the imaging process is provided by CCDAutoPilot3, which allows me to sleep while the imaging system continues its work unattended.  The camera and guider are controlled by CCDSoft5, the acquisition program that makes the most of the capabilities of the Paramount hardware.  MaximDL4 is another excellent image acquisition program that supports a very wide range of mounts and cameras.  Speaking of cameras, I use several made by SBIG.  Other fine cameras are made by FLI, Yankee Robotics, and Apogee.  There are many sources for astro imaging equipment, but I have had nothing but good experiences with Anacortes Telescope and Wild Bird for new gear, and they host an excellent site listing used items, reviews and other resources (AstroMart).

Processing of the images is first accomplished with CCDStack to dark-subtract, apply flats, align, data reject and combine the raw images.  It is usually then off to Photoshop CS2 for final adjustments to the image prior to publication and/or printing. 

A wonderful introduction to "serious" astro imaging is provided by Ron Wodaski's "The New CCD Astronomy", a classic modern treatise on how to do it right.  Ron will release a new book on image processing this Summer, "The Zone System for Astro Imaging".  It is described by Ron as "Everything you need to know for processing CCD and Digital Camera images with Photoshop® CS/CS2".  I've seen the printer's proofs, and it will quickly become a classic also. 




If your eyes follow the movement of the rotating pink dot, you will only see one color, pink. If you stare at the black + in the center, the moving dot turns to green. Now, concentrate on the black + in the center of the picture. After a short period of time, all the pink dots will slowly disappear, and you will only see a green dot rotating if you're lucky! It's amazing how our brain works. There really is no green dot, and the pink ones really don't disappear. This should be proof enough, we don't always see what we think we see.