Astrophotography has become increasingly popular and, thanks to modern technology, these days we don’t need enormous budgets to get great images: even smartphone cameras can give impressive results.
The main consideration when selecting what sort of camera you need for astrophotography is whether you wish to pursue wide-field, planetary, or deep-sky imaging. Typically, any device used for night-sky imaging will need to perform long exposures, have remote shutter capability and ISO control (to alter sensitivity to light).
Here we’re going to run through the most popular cameras for astro imaging, pointing out strengths and considerations. We begin with a type of camera that many people will have with them most of the time.
To get the most out of whichever camera you have, read our astrophotography guides, including our beginner’s tips for image processing. And if you’re on the lookout for your first camera, or perhaps an upgrade, browse all of our camera reviews.
You can also hold smartphones up to a telescope eyepiece to take pictures, or use a smartphone adaptor (more on this below). This enables lunar and planetary imaging, but it’s difficult to get sharp images.
Although some smartphones have multiple cameras installed, these are tricky to line up to eyepieces. In a nutshell, smartphones are not dedicated astrophotography products and don’t offer the exposure control of a DSLR camera.
Best suited for Star trails, Milky Way and general wide-field imaging
Limitations Deep-sky photography
Ideal accessories Tripod, telescope adaptor
DSLRs (Digital single-lens reflex cameras) are good all-rounders. Because you can alter the ISO level and manage exposure lengths, these cameras are easily adapted for many astronomy targets.
Increasing the ISO setting ensures a DSLR can pick up details from deep-sky objects, including nebulae, but if this is coupled with a long exposure time there can be an issue with noise (unwanted artefacts) creeping in, which can be because the ISO is too high (the best ISO varies between cameras) or because the exposure time is causing the sensor to warm up.
DSLRs with ‘Live View’ or video capability can be used for planetary imaging, although they’re less efficient at cutting through atmospheric distortion than a planetary camera. For more on this, read our guide to astronomical seeing.
Some astro imagers modify a DSLR by removing the infrared (IR) filter, which makes it more sensitive to nebulae. A modified DSLR also allows narrowband filters to be used, which improve image details.
Best suited for Wide-field, lunar and deep-sky imaging
Limitations Exposures lasting over ~5 minutes, planetary imaging
Ideal accessories Tracking mount, intervalometer (remote shutter release cable)
Planetary cameras & webcams
Planetary imaging requires a telescope and you’ll find that reflectors are most suitable because of their long focal lengths.
If a planetary camera is also coupled with a 2x Barlow lens you’ll be able to achieve the magnification required for planetary detail, while the camera’s high frame rate will allow you to cut through atmospheric turbulence.
You’ll require a laptop to run these cameras and, as you’re viewing an object up close, a solid tracking telescope mount is also needed, which allows you to keep the planet central in the field of view.
When it comes to deep-sky imaging, planetary cameras have small sensors, which means they’re not always suited.
It’s also possible to modify an off-the-shelf webcam for planetary imaging, so that it fits into the eyepiece holder of your telescope (see below for more details).
Best suited for Lunar and planetary imaging
Limitations Deep-sky objects and wide-field imaging
Ideal accessories Laptop, 2x Barlow lens, processing software (eg RegiStax)
CMOS & CCD cameras
CMOS and CCDs are ‘dedicated astrocams’ designed to be fitted to a telescope. Each comes in ‘colour’ – for RGB (Red, Green and Blue) imaging – or ‘mono’ variants. Mono cameras require the use of colour or narrowband filters.
CCD (charge-coupled device) cameras are suited for long-exposure astrophotography (10-plus minutes per frame) because they have ‘set-point’ cooling systems that keep the sensor temperature constant, which is known as ‘active’ camera cooling.
CMOS sensors perform better with shorter exposures and come as either actively or ‘passively’ cooled.
Laptops are needed to run either device. To maximise CCD exposure times, additional accessories – including guiding equipment and software – are often required. Using these cameras can be a steep learning curve, so it’s best to build up to it gradually.
There are adaptors available that fit these ‘astro cams’ to DSLR camera lenses, which allows you to use them for wide-field deep-sky imaging.
Best suited for Deep-sky imaging
Limitations Milky Way and wide-field imaging
Accessories Laptop, telescope, guide equipment and software
How to link connect a camera to your telescope
You can go far with astrophotography by using a DSLR and lenses, but for a deep-sky object or planetary photography the addition of a telescope to your setup will widen your options. Your target will appear larger, allowing more detail.
Smartphones can be fitted to a telescope eyepiece holder via an adaptor: you just need the right one for your model. If you fancy making your own, read our DIY guide to making a smartphone adaptor for your telescope.
To attach a DSLR you will need a T-ring and nosepiece. The T-ring fits to the camera like a lens. For example, if you are using a Canon DSLR, you’ll need a Canon-fit T ring. The nosepiece is either 2-inch or 1.25-inch and you’ll find that most telescopes take either diameter.
If you are using a webcam, you’ll need to consider modifying it to fit to the scope’s eyepiece holder. This often involves stripping the webcam down to rehouse it in suitable casing. How difficult and effective this is will depend on the model.
If you are using a 2x or 3x Barlow lens and a reflector, you’ll pop the Barlow into the eyepiece barrel before attaching your webcam.
Designated planetary cameras, CCD and CMOS devices, come with a nosepiece attachment that fits to your scope.
Charlotte Daniels is an amateur astronomer, astrophotographer and astronomy writer. This guide originally appeared in the March 2021 issue of BBC Sky at Night Magazine.