We got the chance to review Canon’s mid-range full-frame offering, the Canon EOS R8, to see how it fares as an astrophotography camera.
Cameras have come a long way and, until recently, DSLRs, which use a flip-up mirror to see through the lens, have dominated the market due to their mix of capability and accessible pricing.
But the digital age is maturing and mirrorless cameras are now becoming much more affordable.
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First glance
The Canon EO8 R8 is sturdily built yet incredibly lightweight at just over 450g, so won’t strain the focuser on your telescope.
For standard photography, it has a wide range of useful functions for the creative photographer.
Canon has retained the button and dial layout you’ll find on many others in its range, with only minor changes to the EO8 R8, such as a dedicated switch for still frames or video mode.
It has a smaller battery, which we found lasted for around 180 images, depending on the temperature.
The three nights during the review period were quite cold, which can seriously affect battery capacity.
After each session on one target, we needed to recharge, so we’d suggest either buying spare batteries or using an adaptor to power the camera from an external source.
The Canon EO8 R8’s touch-operated LCD screen can flip out and be tilted, which is very useful when mounted on a telescope, where the back of the camera is often at an awkward viewing angle.
You can also view objects through the LCD viewfinder like on traditional cameras, but bear in mind that both options only work when the power is turned on.
Canon EO8 R8 Touchscreen control
The touchscreen is multifunctional. One essential feature is that the view can be magnified by 5x and 10x, allowing you to zoom in to manually focus on a star, which works brilliantly.
The screen also provides direct access to the shooting mode, ISO and other capture functions useful to astrophotographers, so you can quickly change settings in the field without feeling for the physical buttons.
We would highly recommend turning off the noise-reduction setting for long exposures in the menu or you may find that you lose the fainter stars in your images.
There are so many useful settings, it really is worthwhile studying the manual in detail to get the best out of the camera.
One of the differences between the Canon EO8 R8 and its mid-range sibling the Canon Mk I R6 is that the R8 has only one SD card slot (for a UHS-II SD card, not provided), located in the battery compartment.
Another is that Canon has opted to use a 24MP sensor for the R8, compared with the Mk I R6’s 20MP sensor.
It’s worth noting that the 24MP sensor is used in the latest R6 model, the Mk II.
The difference in image size isn’t that obvious at a quick glance, but in raw image mode using Canon’s CR3 file format, the image dimensions are 6,000 x 4,000 pixels compared with the original R6 Mk I at 5,472 x 3,648 pixels.
Canon EO8 R8 for astrophotography
We attached the Canon EO8 R8 to our RedCat 61 apo refractor and were able to image the Flaming Star region in Auriga, the Orion Nebula up to the Flame Nebula region, and the Rosette Nebula, all captured with a quad-band filter to compensate for light pollution.
Even with the Flaming Star image consisting of only 113 images at ISO 10,000 and 30-second exposures, we were impressed with our results after some processing with Astro Pixel Processor and PaintShop Pro.
Turning to the Andromeda Galaxy, M31, we swapped to using our tri-band filter with the RedCat and again were pleased with the stacked and processed image.
We did find that being a full-frame sensor, the R8 produced distorted stars when combined with our Equinox 80ED refractor and field flattener, which were evident in our image of the Pleiades star cluster, but this was as expected.
Overall, we thoroughly enjoyed using the Canon EOS R8 mirrorless camera, with its lightweight body, easy-to-use interface and impressive performance as an astrophotography device.
We would highly recommend it.
Canon EOS R8 sensor
The Canon EOS R8 boasts a 24.2MP full-frame CMOS sensor.
‘Full frame’ means it is the equivalent of the original standard format for cameras, giving a 3:2 aspect ratio or, to put it another way, 36 x 24mm.
This gives a CR3 raw image size of 6,000 x 4,000 pixels – so plenty of sensor to capture the night sky with.
The ISO range is considerable, going from 100 to 102,400, and is pushable up to 204,800.
However, note that due to light pollution, most of our sky conditions render higher values useless.
The good news is that if you use filters, such as tri- or quad-band filters, then although they do dim the image a little, the mid-range ISO values can help.
Indeed, for all our images taken during the review period, we used an ISO of 10,000, with only slight noise apparent that was easily reduced in processing.
If you’re using a guiding setup, you can reduce the ISO to 6,400 or less to increase exposure times and get even better results.
Canon EOS R8 best features
Camera body
Lightweight and sturdy, the R8 has a range of button and dials for optimising its performance, depending on your astronomy target. Those familiar with Canon cameras will find most of the controls laid out as expected, with just a few minor changes.
Tilting touchscreen
Tilting LCD screens have really helped astrophotographers, as often targets are high in the sky, putting the screen at an awkward position. The R8’s tilting screen shows many of the currently set camera functions. You can also take an image by touching the screen.
Connectivity
A wide variety of options can be found on the side of the camera for attaching accessories such as an intervalometer, microphone and headphones, HDMI output and USB-C connector. The R8 also boasts Wi-Fi and Bluetooth connectivity to control the camera or download images to a smart device.
Detailed menu
The LCD screen provides access to a very detailed menu where many settings can be changed to enable the best data to be captured. This is especially useful for turning off features that may degrade astrophotos, such as the long-exposure noise reduction, or for altering the crop ratio for the sensor.
Battery and charger
Canon provides a camera strap, a charger with a UK-style cable/plug and a single rechargeable Li-ion LP-E17 battery. Under normal daytime use, the battery can last for 370 shots; for astrophotography, we achieved 180–200 shots before it needed recharging. The charger displays an orange light when charging and green when charged.
Key specs
- Price: £1,699.99 (body only)
- Sensor: 35.9 x 23.9mm, 24.2MP full-frame CMOS
- ISO range: 100–102,400 (expandable to 204,800)
- Frame rate: 40fps burst
- Resolution: 6,000 x 4,000
- Body size: 132.5 x 86.1 x 70.0mm
- Connectivity: Wi-Fi, Bluetooth, Canon Camera Connect app, RS-60E3, USB-C, audio/headphones, HDMI
- Weight: 461g (with battery and SD card)
- Supplier: Canon UK
- Tel: 020 7660 0186
- www.canon.co.uk
This review appeared in the March 2025 issue of BBC Sky at Night Magazine
