A beginner’s guide to DSLR cameras
DSLRs offer a simple yet effective way of capturing the night sky. Charlotte Daniels reveals the settings to use to get the best out of them
Capture your best photos of the night sky with a DSLR camera
DSLRs (digital single-lens reflex cameras) are brilliantly versatile astrophotography cameras, and for a wide range of reasons. They perform well for most types of target, including wide-field Milky Way shots, Moon images, and deep-sky objects like galaxies and nebulae. Great for beginners, they are easy to use and can be cheap to buy, depending on the model. Plus, there’s a secondhand market for entry level cameras.
DSLRs have a digital sensor and reflex mirror that directs incoming light onto the viewfinder. You can attach different lenses to them and they are also more sensitive in low light, which is important.
You can get started in DSLR astrophotography simply with the camera and a tripod, rather than jumping straight into guiding. The lenses available also provide the ability to shoot at longer focal lengths before investing in a telescope. There are also many social media groups that showcase DSLR astro images and provide support and advice.
In this guide we’ll outline tips for DSLR astrophotograpy, including preferred specifications, imaging formats and key settings. A variety of Canon DSLRs are used to illustrate this feature; and you’ll find that most models have a similarly recognisable array of buttons and screen settings.
Let’s get technical
The two main kinds of DSLR are full-frame and crop sensor (APS-C). Full-frame DSLRs have a larger chip, giving them a wider field of view and greater sensitivity than those with a crop sensor. Some DSLRs are more suited to astro imaging than others, and the minimum requirements depend on the photos you wish to take. For example, deep-sky imaging requires a DSLR that has ‘Bulb’ mode. This allows you to attach a remote shutter control and shoot multiple long exposure frames. The ability to increase ISO levels is also a must (see ‘Capturing deep-sky objects’ section, page 64).
Meanwhile, lunar and planetary photography benefit most from video, as the high frame rate is better at cutting through Earth’s atmosphere to produce sharp images. A DSLR with video capability is an advantage, but often a fast exposure time is sufficient. DSLRs are also great for wide-field views, because you can attach a wide, fast lens (eg f/2.8).
One thing that your DSLR requires is a ‘Live View’ function; this means that instead of looking through a viewfinder, the image is displayed on its digital screen (see below). This not only helps to line up an image, but means you can achieve sharp focus on stars.
In terms of physical characteristics, this is down to individual preference, but we’ve found that an articulated ‘flip-screen’ can make all types of astro imaging easier. These allow you to view frames from awkward angles, including objects overhead. This combined with a touch-screen LCD is even better, as it helps prevent you from nudging the camera.
Lastly, two rules that apply for all astro imaging are to shoot in ‘Manual,’ and in RAW image format, as this enhances image-editing control. We’ll now take a look at what DSLRs can do, using familiar targets.