It’s certainly possible to just go outside with a camera and take photographs of the night sky. A DSLR on a steady tripod with a wide-angle lens can produce amazing results with a 30-second exposure under dark skies! Everybody should just try this first before buying more expensive equipment and software.
For a deeper look into the cosmos though, we need to use software. There’s a wonderful selection available that makes it surprisingly easy to climb the learning curve toward producing stunning images of the deep sky and solar system. I use software to plan each imaging session, to control the camera and mount, and then to process the images.
There are loads of options, and of course I’m still learning and expanding. “Night scape” photography with a DSLR is much easier using camera control software, even if you don’t want to get into the trouble of telescopes and sky-tracking. BackyardEOS offers a wonderful and comprehensive interface to control every aspect of this process from session planning to framing to focusing to image capture.
For planning I use TheSkyX. I control cameras and mounts with MaxIm DL. After capturing all those photons I use PixInsight to process the data into the images you see here on the website. All of these packages are expensive commercial products. In some sense they are serious overkill and there’s a lot of overlap between them, so you might very well be better off using cheaper (or free!) alternatives.
TheSkyX is called a “planetarium” program, but it also aspires to be a comprehensive suite of tools for planning, observing, and imaging. I’m using it pretty much just for planning these days, but I want to learn more as I go. The program displays the sky in phenomenal detail, and lets me preview exactly what my scope and camera will see anywhere, any time, at any magnification, etc. It lets me set ”Field of View” options that specify the exact imaging chip and pixel size, guide stars, and orientation I’ll use to get the best image.
Optionally, TheSkyX can control the mount, camera, rotator, observatory dome, and schedule the entire imaging session. So far, I haven’t used this functionality. My next step with this software will be to learn to use “T-Point,” which measures and models pointing errors for the telescope mount and vastly improves the accuracy. When using a calibrated T-Point model, my observatory scope should be able to center anything in the sky on the imaging chip without any help from me. This will make it easier to someday automate the imaging process (at least down here in high-tech suburbia).
MaxIm DL is an (almost) all-purpose astro-imaging program with support for telescope mount control, camera control, auto guiding, observatory dome control, and image processing. It is extraordinarily well-integrated with the ASCOM platform for cross-compatibility among astronomy software. It even has a rudimentary planetarium program built in, so it would be possible for me to just use this one program and skip both TheSkyX and PixInsight. I prefer to use MaxIm just for the image capture process (camera control and guiding), because the other programs work better for me. This is partly because MaxIm only runs in Windows and I prefer to use the Mac when I can. Both TheSkyX and PixInsight work with the Mac.
I use PixInsight for post-processing of deep-sky images. Raw camera files (“data”) have to be calibrated by subtracting electronic noise using dark and bias frames, then dividing by flat frames. Then sometimes dozens of resulting “subs” have to be aligned and stacked by averaging red, green, and blue pixel values after excluding outliers. The software analyzes background light pollution or moon light that varies across the frame and corrects it. The resulting image is then “stretched” to bring out very faint details while avoiding saturation that would “blow out” bright areas like stars. Noise reduction and sharpening can be applied very selectively to different parts of the image.
Many astro-hobbyists use separate programs to do the initial calibration (Deep Sky Stacker, ImagesPlus, and CCDStack are some popular options), and then do almost all the post-processing in Adobe Photoshop. I started out this way too, but I have switched to PixInsight because it is a dedicated end-to-end astronomy solution that runs on Windows, Mac, or Linux; because my results are much better; and because I can grow with the software as I learn more. Also, it is much cheaper than any of the alternatives and there is a vast user support community.
I’m just beginning to experiment with automation of the imaging process. It is possible to make the mechanics and electronics of data collection almost completely automatic, including opening, rotating, and closing the observatory dome; slewing and guiding the telescope mount, controlling the cameras, and uploading the images. Some people do all this from thousands of miles away, completely hands-off. This seems like too much trouble to me, and I need to get way better at manual control before I hire robots to do it all for me. But at some point I will probably use CCD AutoPilot to help with scope and camera control at the cabin, and ACP to help control the observatory.