As amateur astronomers, we love to gaze at the night sky. But how much can we really see with just our eyes?
Astrophotography can be a great way to capture images of distant objects that we can’t fully see with our own eyes. This is because a camera can collect light for many hours, unveiling colour and details hidden from our less-light-sensitive eyes. Although it can be a richly rewarding hobby, it can also be one that bankrupts you.
There are different ways of capturing images of the universe. To start off, you might take wide-field shots of the night sky. This is fairly simple and cheap. Any camera with a manual shutter will do, but you will need a tripod. Set it up for an exposure of a few seconds, and — click! — you have an image of the night sky.
But, if you’re looking to capture distant objects, you might want to use a DSLR camera. The downside of using a DSLR, is the infrared filter in front of the sensor which renders colours correct for daytime photography blocks some of the wavelengths of light we want to capture in astrophotography. none the less, if you already have a DSLR, this is a good camera to start with. Other things you’ll need are: an adapter to attach the camera to the telescope; a good, sturdy mount (an equatorial mount is best); and lots of patience. Astrophotography is a waiting game and requires a lot of trial and error at first.
To increase the quality of images, many people move on to a dedicated astronomy camera. These cameras do not have an Infrared filter in front of the sensor like a dslr. They may also have additional circuitry to cool the sensor to a specific temperature to reduce the amount of electronic noise generated by the sensor and other camera circuitry. They have no controls on the camera body and must be run from a computer with appropriate software. These cameras can be colour or monochrome. For a monochrome cameras, different filters are needed (red, blue and green referred to as RGB). You must then combine the three colour channels using stacking software such as SIRIL, deepskystacker ,pixinsight or sharpcap to name a few.
Attached are two tutorials for editing asto photos, one for Lightroom and one for Photoshop. Both document were created and kindly provided by RASC member Benjamin Lappalainen.