Astrophotography-specific enhancements have been made to Canon’s full-frame mirrorless EOS R camera, resulting in the creation of a new model called the EOS Ra. Due to the fact that its infrared filter is four times more sensitive to hydrogen-alpha radiation than most others, it is ideally suited for photographing nebulae. Accurate focusing is made possible by the capability of magnifying the scene by up to 30 times.
Aside from that, the EOS Ra has the same capabilities as the standard model, including a CMOS sensor that offers a resolution of 30.3 megapixels and a Dual Pixel AF.
Both the 14-bit (CRW) and compressed (C-RAW) recording formats are supported by the EOS R. It is capable of continuous shooting at 8 frames per second when using single AF and 5 frames per second when using continuous AF. The staggering Dual Pixel AF system has 5655 selectable AF points, and it can operate in light levels as low as -6EV. Additionally, it has a low minimum exposure value.
In addition to a fully articulating touchscreen LCD measuring 3.2 inches and 2.1 million dots, the small body features an OLED electronic viewfinder with 3.69 million dots and 0.76 times magnification. An OLED LCD is located on the top plate and shows the information on the current shooting.
In addition to a 3.5mm external microphone jack, the Canon EOS R features a Mini-HDMI connector and a USB-C port. According to the CIPA, the battery life is rated at 370 shots per charge (450 using Power Saving Mode). There is a battery grip that may be purchased. The EOS R only has one slot for memory cards, although it is compatible with UHS-II storage media.
With ALL-I or IBP compression and a maximum bit rate of 480 MBps, it is possible to record 4K UHD video at a frame rate of up to 29.97 frames per second. You’ll need to switch to Full HD if you want to watch videos at 60 frames per second.
Body And Controls
The Canon EOS Ra mirrorless camera follows the overall style and ergonomics of the EOS R line of mirrorless cameras, and there is very nothing that differentiates it from the Canon EOS R other than the fact that it has “Ra” printed on the body. The Canon EOS Ra is a sleek and beautiful camera that fits comfortably in the palm of your hand and has angular curves and button placement.
When moving from a standard Canon DSLR or another brand of DSLR or mirrorless camera to an EOS Ra for the first time, the placement of dials, buttons, and the overall handling of the camera may appear a little off to the user.
This, however, is quickly remedied, and it doesn’t take long to acclimatize to the camera’s layout and understand that, in point of fact, it is both original and rational in its design. Your hands will immediately grow accustomed to it, and its more compact and lightweight form, as well as its handling, will fast become the standard; in fact, picking up another camera so soon afterward will seem foreign to your hands.
It may take some time to get used to the digital mode button that is located within the traditional shutter speed dial, and the multi-function bar that is located to the right of the viewfinder may get in the way of people who have hands that are particularly large. However, the handgrip is of a good size and is comfortable (if necessary, multifunction bars can be switched off). The Canon EOS Ra is protected from the elements, but not to the same level as regular DSLRs like the Canon 5D MK4.
When compared to other manufacturers, the level of customization is rather lacking; yet, it is straightforward to assign broad functions to the various buttons and dials. By holding the button down and turning the dial, the standard AF-ON and AEL buttons may be reprogrammed to alter ISO or other instructions instead of their normal functions.
The customization of the ISO button is relatively crucial for general ease of use while grasping the camera in the dark. As an alternative to moving half of your hand, searching for the rear, or top-placed ISO button, you can simply change the position of the button on the camera. The quick (Q) menu, on the other hand, cannot be customized; as a result, a few of the menu selections that you might wish to move over cannot be done, and you will be required to personalize another button.
The 30X focus magnification, which makes focusing through a telescope simpler than the standard 10X magnification, is one of the important selling factors for astrophotographers. In addition to the evident H-Alpha sensitivity, this is one of the key selling features for astrophotographers.
This is also helpful for landscape astrophotographers and photographers working in low light, particularly when focussing on features like the moon’s surface. It does make it simpler to focus on dimmer stars when using wide lenses; but, you may find that you need to go back to 10X magnification while working with brighter stars at times.
When used in conjunction with the Canon EOS Ra, fast lenses make it possible to utilize autofocus on the stars in the dark as long as they can be viewed clearly. All that is required is to autofocus on a brilliant start and then switch off autofocus; this is possible even with wide-angle lenses.
The touchscreen mechanism utilized by Canon is nothing short of flawless.
It is a touchscreen system that actually makes you want to use it due to how fluid it feels and how easy it is to control the camera using it, which is not the case with some other mirrorless brands. The reason for this is that it makes you want to use it because of how easy it is to control the camera using it.
Once the LCD has been flipped out from its housing, it is able to rotate through a full 360 degrees. This is a very useful feature, particularly for astrophotography, which requires the camera to be held at unusual angles. This allows you to position the screen so that it is facing you, and you can use the touch screen to control the camera.
There is a significant drawback to the layout of the screen. The L-bracket plates that are commonly used by landscape astrophotographers to hold their cameras prevent the LCD from being able to flip out of the way, which in turn prevents it from being able to spin.
In addition, Canon RF lenses feature a control ring that can be customized and located on the front of the lens. This ring may be altered to regulate aperture, shutter speed, ISO, and other settings, which adds further versatility to the camera customization process.
The Performance of Autofocus and the Buffer
When compared to the greatest DSLR options available, the restricted focusing capabilities of mirrorless cameras used to be a major drawback of these types of cameras. This status quo has been steadily undermined, with Sony leading the fight; specifically, the A7 III and A9, both of which boast outstanding focusing systems that are capable of delivering high levels of performance.
After the launch of the EOS R, it became Canon’s responsibility to develop an autofocus system that could compete with the company’s DSLR bodies and that could also match the performance of its mirrorless competitors. The EOS R has Canon’s Dual Pixel on-sensor focusing technology, which provides over 5655 AF points and covers 88 percent of the frame horizontally and 100 percent of the frame vertically.
When compared to Canon’s full-frame DSLRs, which have the majority of their AF points grouped closer to the center of the frame, the sheer number of focus points offered by this camera is particularly appealing. Notably, the focus is supposed to function down to -6 EV when used with an f/1.2 lens and -3 EV when used with an f/2.8 lens. Additionally, Canon says that a large number of adapted EF lenses should focus without any issues when used with the EOS R.
The Canon EOS R lacks a dedicated button for switching between the different focusing modes. When switching between One-Shot AF and AI-Servo, Canon anticipates that you will use either the M-Fn button, the Quick Menu, or a button that you have customized yourself. For my own convenience, I’ve decided to make the AE Lock button (represented by an asterisk) the one that toggles between One-Shot AF and AI-Servo.
The well-known AF point selection button can be found on many of Canon’s DSLR models and may be located directly below the AE Lock Button. Although this button behaves like a Custom button that can be programmed to perform any number of functions, I have mine set to Direct AF Method Selection. This allows me to quickly cycle through the various AF area modes, which include Face/Tracking (with optional eye detection, although this is only available in One-Shot AF), Single Area (Small and Normal), and Expanded AF (Surrounded), and Zone AF. Face/Tracking is only available in One-Shot AF. Single Area (Zone, Large Zone Vertical, and Large Zone Horizontal).
Because there is no dedicated AF joystick, you will need to shift your AF points about by using the touchscreen, the control knobs, or the cross-keys on the four-way directional pad.
You have an incredible amount of flexibility over the selection of individual AF points when you use the four-way directional pad, but since there are so many of them, it can take a significant amount of time to move your AF point across the picture field.
Your best chance is to utilize the touchscreen on the back of the camera, which gives you the ability to swiftly tap to relocate the autofocus area or drag it across the frame to the region you want it to be in.
The touchscreen functions as a touchpad when you are composing through the viewfinder, which enables you to shift your autofocus points around without ever having to remove your eye from the electronic viewfinder (EVF). You may pick the touch and drag AF settings from the camera menu by going to the AF1 tab and clicking there.
This gives you the ability to choose between “absolute” placement and “relative” positioning, both of which I have previously discussed to you. When using the screen as a touchpad, you have the option of selecting how much of the screen will remain active (for example, I left my active touch area to the default Right side of the touchscreen so that my nose wouldn’t inadvertently move the AF points while using the EVF). This option can be found in the same menu as the option for using the screen as a touchpad.
Autofocus in a Single Shot
The autofocus on the EOS R is outstanding for use with stationary subjects, achieving focus in a very short amount of time and with a high degree of precision. It also performs remarkably well in low-light settings.
When used in conjunction with native RF lenses, the EOS R’s One-Shot AF is simply exceptional in terms of both its speed and its level of precision. When photographing static subjects, the focusing ability of an EOS R camera is far better than that of a Canon DSLR.
Mirrorless cameras, on the other hand, focus directly on the sensor plane, as opposed to DSLR cameras, which feature a separate phase-detection focusing mechanism that does not always match the lens. This very much does away with any focus differences that may exist between the camera body and the lens, and it also does away with the requirement that lenses be fine-tuned to the camera body.
I observed that images made in One-Shot AF were continuously in excellent focus, and this high performance continued even while shooting in low-light circumstances, which is an area in which the EOS R is truly outstanding.
When using a lens with an aperture of f/1.2, Canon states that the EOS R can focus down to -6EV, which, based on my observations made in the field, appears to be a true statement. The EOS R has the best autofocus performance in low light that I have seen on a mirrorless camera, and it does a fantastic job of focusing on stationary things overall.
Face Detect Autofocus
Face Detection, along with pupil detection as an additional available feature, is an important component of the autofocus system on the EOS R. This is a function that is quite similar to Sony’s Eye AF, with the exception that eye detection on Sony cameras works in both the AF-S and Continuous Shooting modes, however on the EOS R, pupil detection is only accessible in the One-Shot AF mode.
During my testing, I found that the EOS R’s face detection had a somewhat inconsistent performance. Even when using a lens with an aperture of f/1.2, you can expect to have a reasonable percentage of shots that are in good focus even though the EOS R’s ability to nail the eye of my subject in certain scenarios impressed me. Additionally, as long as your subject’s face takes up a relatively large portion of the frame and they don’t move, you can also expect to have a good percentage of shots that are in good focus.
Sadly, there were also many instances in which the focus would latch onto a face and then abruptly leap off toward the rear of the head or body even though the face was extremely noticeable in the frame. This occurred even when the face was the primary subject of the photograph.
Because Face and Pupil Detection only works when the camera is set to One-Shot AF, it is important to keep in mind that if the face of your subject moves even slightly between the time the camera locks focus and the time you press the shutter button, there is a good chance that the eye will no longer remain in focus. This is something that should be taken into consideration.
In this aspect, Sony’s mirrorless solutions have a significant edge since they are able to apply their Eye Detection AF in Continuous AF with the camera keeping track of your subject’s face and eye as they move in-between frames. This gives them an advantage over their competitors. In comparison, the Face Detection on the EOS R seems to be quite a ways behind Sony’s face and eye detection, which continues to be the gold standard in the industry. I
In the end, I frequently discovered that I was using a single AF region over an eye or face in the frame rather than face detection, which meant that I had to turn off face detection.
AI-Servo (Continuous Autofocus)
The AF mechanism of the EOS R is pretty good when used in continuous focusing, however, the Subject Tracking mode is hindered by erratic hunting.
Throughout the majority of my testing, the Canon EOS R did a respectable job of maintaining a good focus on the things I was photographing, and I was able to produce a high percentage of in-focus photos when I used favorable shooting settings.
This performance changed while I was shooting in low-light conditions when I saw a significant drop in the percentage of photos that were in focus compared to what I got when using the Canon 5D Mark IV. Unfortunately, the continuous shooting capability of the EOS R is severely constrained by the performance characteristics of the camera.
Monitoring of Subjects
You also have the option of using AI-Subject Servo’s Tracking feature, which identifies a subject based on its color and shape and surrounds it with a shape-shifting rectangle that varies in size depending on where the subject is located in the frame. This feature is only available when AI-Servo is enabled.
It is essential to ensure that you retain control over the location at which the camera begins focusing when utilizing the Subject Tracking feature. This is accomplished through Sony’s Lock-On AF, which gives you the ability to position the camera’s focus point directly over the subject you wish to photograph, and then, after you begin focusing on the subject, the camera begins to track it from the position where you first positioned the focus point.
On the EOS R, a comparable option may be found, although it is not activated by default. To make this adjustment, go to the AF Menu Tab, choose AF5, and then find the section labeled “Initial AF pt set for Face + Tracking.” Here, alter the setting from AUTO to manual selection.
If you change this setting, you’ll be able to position the autofocus area directly over your subject using the touchscreen. This will start subject tracking, and when it does, you’ll see that the camera creates a shapeshifting box around your subject and tracks it as it moves across the frame.
The use of this technology is fairly successful, and the high-quality touchscreen included on the EOS R makes the process quite easy to navigate.
Performance With Adapters for the EF to the EOS R
Because there were so few native mount RF lenses available when the camera was originally introduced, it was important for Canon to find a solution to combine current EF lens packages alongside their first full-frame mirrorless camera.
The use of a mount adapter was the natural decision since it enabled Canon to build a completely new and advantageous RF lens mount while yet preserving full compatibility with older EF lenses. When the Canon EOS R was originally made available to the public in the month of October, the Canon Mount Adapter EF-EOS R was the very first accessory that could be purchased for use with it.
You may use EF, EF-S, and TS-E lenses on cameras that have an RF mount if you have an adaptor called the Canon Mount Adapter EF-EOS R. This adapter is a simple piece of hardware. The adapter keeps all of the autofocus and image stabilization features of the lens that it is put onto. Additionally, the adapter does not include any optical components, which ensures that there are no alterations made to the lens’s original optical quality.
It is also resistant to dust and water, making it suited for usage in settings where there is a combination of the two. When put to use, the adapter functions faultlessly with already existing EF lenses. In fact, the performance of these lenses on a Canon DSLR camera body and the EOS R is so similar that it will be difficult to tell the difference in many situations.
I was able to utilize the EOS R with both the Tamron 100-400mm and the Sigma 100-400mm lenses since the adapter works with current third-party lens alternatives made for the Canon EF mount.
It’s interesting to note that the Canon Mount Adapter EF-EOS R is simply one of four distinct adapters available for RF mount that convert EF lenses to EOS R cameras.
The second adapter, which follows the same idea as the base adapter but also includes a control ring that can be customized, has an even longer name than the first adapter, and is called the Canon Control Ring Mount Adapter EF-EOS R.
This ring is quite similar to the one that can be found on lenses with a native RF mount, and it provides the same functionality, which includes the changing of exposure parameters such as ISO, aperture, and exposure compensation.
The last adapter(s) is/are the Canon Drop-In Filter Mount Adapter EF-EOS R, which gives you the ability to put a filter in between your camera and your lens.
You have the option of purchasing the Drop-In Filter Mount Adapter EF-EOS R with either a circular polarizer filter or a 1.5-9-stop variable neutral density filter when you make your order. The filter features a tiny exterior wheel that, when turned, makes the appropriate changes to the internal rotation, allowing you to set the filters to the correct level of filtration.
The shooting speed as well as the buffer
One-Shot AF is the sole autofocus mode that supports the Canon EOS R’s maximum shooting speed of up to 8 frames per second. Canon’s documentation indicates that the maximum burst speed with AI Servo activated is 5 frames per second, which is slower than the 5D Mark IV’s maximum of 7 frames per second. In comparison to the Nikon Z6 and the Sony A7 III, the maximum burst speed of the EOS R is much slower.
The Nikon Z6 has a top-of-the-line burst shooting rate of 12 frames per second; however, I should point out that this is in “extended” mode. Even if the viewfinder is unable to keep up with a live view and the exposure is fixed on the initial frame, the Z6’s “extended” mode impressively maintains continuous focusing.
Without such restrictions, the maximum burst speed of the Z6 is 5.5 frames per second. You get 10 frames per second with continuous focusing while using the Sony A7 III, however, this decreases down to 8 when using live view.
Examining the Image’s Quality
Impressive picture quality could be seen in the photographs produced by the combination of the EOS Ra with the 85mm F/1.2L lens. Each exposure lasted for thirty seconds, and there was very little noise in spite of the fact that ISO 800 was used.
Image Format (RAW)
RAW photos captured by the Canon EOS Ra are saved in the.CR3 format. This seemingly little shift in the file extension from.CR2 to.CR3 used by Canon DSLR cameras is, in fact, rather significant. This new file format has to be compatible with every piece of software you use, including the ones you need for picture editing, registration, and calibration.
For instance, the pre-processing program that I use (DeepSkyStacker) is compatible with RAW picture files.CR2 extension, but not those with the.CR3 extension. This indicates that in order for the program to identify the native RAW picture format that the Canon EOS Ra produces, I will need to convert it to an a.TIF file.
Despite the fact that Adobe Photoshop 2020 has no issue opening.CR3 files in Adobe Camera Raw or Bridge (or Lightroom for that matter), I continue to utilize DeepSkyStacker for the registration and calibration stages of the processing of my photographs.
The processing phases of astrophotography require more time as a result of this change, and I am hopeful that the software that is now available will eventually “catch up” to the new image format. Users of PixInsight will need to wait for LibRaw to add support for CR3 files before they can integrate data (the PixInsight RAW format support module uses LibRaw as a back-end to support digital camera raw formats).
It is possible to get around this issue by registering all of your exposures in Adobe Photoshop; but, I am not aware of a technique to calibrate photographs using this method that contain black frames or flat frames.
Full Frame CMOS Sensor
The full-frame CMOS hydrogen-alpha sensitive sensor is likely the feature that will appeal to consumers the most about the camera. You have the option of switching to “crop mode” inside the settings of a camera body that has a crop sensor if you wish to shoot using the field-of-view that you are accustomed to using with other cameras.
The Canon EOS 5D Mark II and the Canon EOS 6D Mark II were the only full-frame camera sensors that I had ever used for astrophotography up to this point. The camera bodies, on the other hand, were both of the stock kind.
Finally, with the help of the EOS Ra, I was able to use the big image circles of my apochromatic refractor telescopes, such as the William Optics RedCat 51 and the Radian Raptor 61, to good use.
If you so wish, you may go into the settings of the camera and manually modify the cropping or aspect ratio of the photograph. The vast majority of photographers will just keep their cameras in the “FULL” (full-frame) mode, but there is also the ability to take pictures with a cropped sensor (1.6X), 1:1, 4:3, and even 16:9 aspect ratios.
When contemplating the EOS Ra, it is important to keep in mind that a full-frame sensor (with a resolution of 6720 by 4480 pixels) requires a level field as well as a big-picture circle. You always have the option of manually adjusting the crop factor on the camera if the picture circle of your optical device is not big enough to fit the large sensor.
4K Video at 30 FPS
The 4K video mode at 30 frames per second is one of the characteristics that a lot of folks choose to overlook when they gripe about how costly this camera is. The video was captured with a full-frame mirrorless sensor, and the resulting quality is just astounding.
Is it really unlikely that those interested in astrophotography will make use of this feature? Perhaps. Because I have shot and edited more than one hundred films on YouTube, I believe this to be an intriguing possibility, and it is one that I would make use of if given the chance.
In point of fact, I put the video capabilities of the Canon EOS Ra through its paces by shooting some daylight footage for one of my films. Despite having almost four times the sensitivity to H-Alpha than a typical EOS R, I was rather surprised to see that the colors were not too far off from what I would consider a “normal-looking” scenario.
If the video is filmed using a neutral or flat color profile, there is a good chance that a natural color correction can be performed through post-production editing. The EOS Ra comes with a useful function called color temperature correction, which helps fix the white balance setting of the photos and videos being captured. There are nine degrees of control for each of the adjustment settings, which are either a blue/amber bias or a magenta/green bias.
This camera supports an astonishing variety of video recording formats, with the highest resolution being 4K at 30 frames per second (ALL-I compression). Shooting in 4K @ 23.97 frames per second in IPB format is the most sensible choice for the way I approach filming and editing projects.
It takes a lot of processing power and memory to edit footage shot in ALL-I format at 4K resolution.
Canon EOS Ra Specs
|Body type||SLR-style mirrorless|
|Max resolution||6720 x 4480|
|Other resolutions||4176 x 2784 (1.6x crop)|
|Image ratio w:h||1:1, 4:3, 3:2, 16:9|
|Effective pixels||30 megapixels|
|Sensor photo detectors||32 megapixels|
|Sensor size||Full frame (36 x 24 mm)|
|ISO||Auto, 100-40000 (expands to 50-102400)|
|Boosted ISO (minimum)||50|
|Boosted ISO (maximum)||102400|
|White balance presets||6|
|Custom white balance||Yes|
|JPEG quality levels||Fine, normal|
|Autofocus||Contrast Detect (sensor)Phase DetectMulti-areaCenterSelective single-pointTrackingSingleContinuousTouchFace DetectionLive View|
|Number of focus points||5655|
|Lens mount||Canon RF|
|Focal length multiplier||1×|
|Articulated LCD||Fully articulated|
|Screen type||TFT LCD|
|Minimum shutter speed||30 sec|
|Maximum shutter speed||1/8000 sec|
|Manual exposure mode||Yes|
|External flash||Yes (via hot shoe)|
|Continuous drive||8.0 fps|
|Self-timer||Yes (2 or 10 secs)|
|Exposure compensation||±3 (at 1/3 EV, 1/2 EV steps)|
|AE Bracketing||±3 (3 frames at 1/3 EV, 1/2 EV steps)|
|Modes||3840 x 2160 @ 30p / 480 Mbps, MOV, H.264, Linear PCM3840 x 2160 @ 30p / 120 Mbps, MOV, H.264, AAC3840 x 2160 @ 24p / 480 Mbps, MOV, H.264, Linear PCM3840 x 2160 @ 24p / 120 Mbps, MOV, H.264, AAC3840 x 2160 @ 23.98p / 480 Mbps, MOV, H.264, Linear PCM3840 x 2160 @ 23.98p / 120 Mbps, MOV, H.264, AAC1920 x 1080 @ 60p / 180 Mbps, MOV, H.264, Linear PCM1920 x 1080 @ 60p / 60 Mbps, MOV, H.264, AAC1920 x 1080 @ 30p / 90 Mbps, MOV, H.264, Linear PCM1920 x 1080 @ 30p / 30 Mbps, MOV, H.264, AAC1920 x 1080 @ 24p / 90 Mbps, MOV, H.264, Linear PCM1920 x 1080 @ 24p / 30 Mbps, MOV, H.264, AAC1920 x 1080 @ 23.98p / 90 Mbps, MOV, H.264, Linear PCM1920 x 1080 @ 23.98p / 30 Mbps, MOV, H.264, AAC1280 x 720 @ 120p / 160 Mbps, MOV, H.264, Linear PCM|
|Storage types||SD card (UHS-II supported)|
|USB||USB 3.2 Gen 1 (5 GBit/sec)|
|USB charging||Yes (With some chargers)|
|Wireless notes||802.11b/g/n + Bluetooth 4.1 LE|
|Remote control||Yes (via smartphone)|
|Battery description||LP-E6N lithium-ion battery & charger|
|Battery Life (CIPA)||370|
|Weight (inc. batteries)||660 g (1.46 lb / 23.28 oz)|
|Dimensions||136 x 98 x 84 mm (5.35 x 3.86 x 3.31″)|
Since the Canon EOS Ra and the Canon EOS R are physically indistinguishable from one another, we had the same range of feelings regarding the cameras’ handling. However, this camera was developed for a very specific application, and many of these peculiarities are rather irrelevant in this context.
The limited 4K footage is of considerably less importance, and the lack of in-body image stabilization is irrelevant with a camera that is likely to be used on a tripod. The lens Control ring is a good feature, being simpler to find in darkness than buttons and knobs.
When compared to other types of cameras, the EOS Ra stands out due to the expanded infrared sensitivity of its sensor as well as the enlarged 30x magnification that allows for more accurate confirmation of focus.
Due to the fact that this is one of just a few commercially available cameras that have been modified specifically for astronomical photography, it does not have a great deal of competition. In spite of the fact that we have certain reservations regarding some features of the ordinary EOS R’s design and handling, we find that these reservations are of far less significance in this arena, and the camera’s capabilities begin to become more apparent.
The EOS Ra version of the camera has a price premium of 20-25 percent in comparison to the ordinary camera, although this does not appear to be a significant amount for a specialist conversion of this sort.
Canon EOS Ra Price
Pros & cons
- Good image quality
- Incredible AF performance
- Excellent EVF
- Solid build
- Single card slot
- Cumbersome LCD
- Subpar ergonomics