Canon EOS R System questions answered: all you want to know about the EOS R

Cross-section showing inside a Canon EOS R camera and RF lens.
Canon's revolutionary full-frame mirrorless EOS R System and RF lenses take photographic technology to the next level.

The EOS R System, Canon's groundbreaking full-frame mirrorless camera system, opens up new creative possibilities for photographers and filmmakers. At its heart is the innovative RF Mount, enabling a range of pioneering new RF lenses. In addition to the four acclaimed RF lenses available at the launch of the EOS R System, Canon has announced six RF lenses for release in 2019, which will expand the EOS R System and set new standards in optical excellence.

The EOS R, Canon's first full-frame mirrorless camera, was revolutionary for photographers and filmmakers. The Canon EOS R range now includes the Canon EOS RP, which puts the power of full-frame mirrorless into a small, lightweight body, ideal for amateur photographers who are ready to take their photography to the next level.

So is an EOS R or EOS RP right for you? What advantages does full-frame mirrorless offer? Does the EOS R System offer better image quality than a DSLR? Can you use your existing lenses and accessories? We put 10 frequently asked questions to Mike Burnhill, European Technical Support Manager at Canon Europe.

A Canon EOS R camera showing the RF mount.
At the heart of the Canon EOS R System is the innovative RF Mount, with a wider throat, shorter flange distance, and super-fast communication between lens and body built-in.
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1. What is a full-frame camera, and what advantages does full-frame offer?

"A full-frame camera is one with an image sensor that measures 24x36mm, which are the same dimensions as a frame of traditional 35mm film, hence 'full-frame'. Early digital cameras often used a smaller sensor but the same size lenses, but full-frame can use the full area of the lens coverage. That's the first advantage: with the same lens and focal length, a full-frame camera captures more of the scene without the 'crop factor' of a smaller sensor camera.

"Another advantage follows from the simple fact that the sensor is larger than APS-C sensors, which are 15x22mm. So a full-frame sensor has 2.5 times the surface area of an APS-C sensor. This means that even if the sensors have the same number of megapixels, the photosites on the full-frame sensor are larger, so they can capture more light, and images therefore have greater dynamic range, with more detail in both shadows and highlight areas. At higher ISO settings, this also means less image noise.

"Characteristically, full-frame cameras offer shallower depth of field and greater control over depth of field than cameras with APS-C or smaller sensors. Portrait photographers in particular love that, because it helps subjects stand out more clearly from appealingly-blurred backgrounds."
Diagram of the EOS R’s sensor showing the maximum 5,655 AF points.
Canon's Dual Pixel CMOS AF technology means every pixel in the sensor can be used for both imaging and AF, ensuring sharpness right across the frame and enabling an astonishing number of selectable AF points on the EOS R's touchscreen.

2. What is a mirrorless camera, and what advantages does mirrorless offer?

"When we talk about mirrorless in this context, we mean an interchangeable lens camera which doesn't use a single-lens reflex mechanism (mirror), but instead an electronic viewfinder (EVF). The biggest advantages come from the fact that eliminating the mirror removes certain restrictions in lens design.

"Because you have a mirror in a DSLR, which has to have room to flip up out of the way when you take a picture, you basically have to work around that mirror system when you design a lens. If you want to make a 21mm lens, the centre of the lens should be 21mm from the focus point on the sensor. But if you have a 40mm mirror in the way, the lens can't be 21mm away. Therefore you have to add extra elements to move all the optics forward, and more glass to alter the focus point, and lenses become much more complex pieces of engineering. If you eliminate the mirror, you've got potentially much simpler lens design, so you can concentrate on image quality instead of constantly having to fight around the design issues.

"In fact, when Canon developed the EOS R System, we didn't start with the decision to build a mirrorless camera. We began by asking 'What's the future of lens design? Where do we want to go with lenses?' The impetus was 'reimagining optical excellence', which led to the internal codename Project R, and that's how it comes to be named EOS R."

Cross-section showing inside the Canon EOS R’s EVF.
One advantage of a mirrorless system with an electronic viewfinder (EVF) is that it enables you to see what the camera sees, even in conditions too dark for the unaided eye to see anything.

"The key decision was the development of the RF Mount, which is at the heart of the EOS R System. It has a wide throat similar to the EF mount, and a shorter flange distance from the mount to the sensor, so we can create groundbreaking new lenses that work at the optimum distance from the sensor. This enables the creation of faster, brighter, higher-quality optics with future-proof performance. The RF Mount also has an innovative 12-pin connection that enables radically faster communication between the lens and the body. One result of this is that the EOS R has lightning-fast AF (the world's fastest for full-frame mirrorless, interchangeable lens cameras) and extremely effective real-time Digital Lens Optimization.

"Another advantage of eliminating the mirror is that the camera body can be smaller and lighter. With battery and memory card, the EOS R weighs 660g and the EOS RP just 485g – significantly less than a comparable full-frame DSLR such as the Canon EOS 5D Mark IV, which weighs almost 800g. There are lighter cameras out there, of course – the compact mirrorless Canon EOS M, for example, weighs under 300g – but with the EOS R our aim wasn't to make the lightest camera possible. We took the decision to construct the EOS R body using robust magnesium alloy, with pro standard sealing for dust and water resistance, because reliability and durability are important to the photographers we designed the EOS R for.

"There are a few technical advantages to a mirrorless design, such as eliminating the vibration caused by 'mirror slap', but that is likely to be a concern only in a few very specific circumstances. More generally, getting rid of the mechanical mirror means the EOS R System is capable of completely silent shooting, which means you can shoot more discreetly in all kinds of settings, from weddings to wildlife photography. Using an EVF also makes it possible to live-preview your image with your shooting settings applied, as well as to see what you're shooting in previously prohibitive low-light conditions."

Diagram showing communications between the lens microprocessor and image processor.
The Digital Lens Optimizer (DLO) technology built into the EOS R System takes full advantage of the RF Mount's super-fast communication between lens and camera body, and the speed of the DIGIC 8 image processor, to get the best from your lenses.

3. When looking at the EOS R's low-light performance, what does -6EV mean?

"The Canon Dual Pixel CMOS AF technology in the EOS R provides high-performance focus tracking in still photos and movies. It results in fast, accurate autofocus even in the kind of low-light conditions it was previously too dark to focus in. In one-shot mode, with a Canon RF 50mm F1.2L USM lens, the AF is effective down to -6EV on the Canon EOS R, or -5EV on the Canon EOS RP.

"To give you an idea of how dark that is: imagine you're out in some remote area at night, where there are no street lights and the only light is a half-moon. That's about the same brightness as -6EV. It will focus in those conditions, as long as there's some contrast. No camera will focus with zero contrast – if you point it at a white wall, no matter how bright it is, it won't focus, because there's nothing to measure between."

4. Does the EOS R System offer better image quality than a DSLR?

"It partly depends how you measure 'better'. On an EOS R the RF 50mm F1.2L USM lens captures a sharper image than the EF equivalent, the EF 50mm f/1.2L USM – but you might prefer a softer look for some portraits, for example. That said, by most criteria the EOS R System sets a new standard in full-frame image quality. The Dual Pixel CMOS AF sensor delivers a perfect balance of rich, sharp detail and incredibly reliable low-light performance, and because almost every pixel in the sensor (100% vertically and 88% horizontally) is used for both imaging and autofocus, it ensures outstanding sharpness right across the frame.

"Many people like Canon photographic tech because they like the way we process colour, but the real test of image quality is not JPEGs straight from the camera. Take a look at the RAW files from an EOS R or EOS RP and you'll be blown away by the richness of the image data captured by the sensor. The Digital Lens Optimizer (DLO) technology built into the EOS R System takes full advantage of the super-fast communication between lens and camera body to make the most of the groundbreaking RF lenses. The camera actually knows whether you're using an RF or an EF lens. It accesses lens profile information directly to correct optical aberrations, diffraction and so on, ensuring optimum image quality.

"The Canon EOS R sensor is from the same family as the sensor in the Canon EOS 5D Mark IV – it has different filters and new electronics, for a better signal-to-noise ratio and other enhancements, but it's the same family. If you compare the images from the two, particularly if they've been shot with RF lenses on the EOS R, I think there's no disputing that image quality is improved. What you get is closer than ever before to how the scene appears to the naked eye."

A photographer holds the EOS R with the screen tilted upwards to take a photo.
The Canon EOS R's vari-angle touchscreen makes it possible to shoot from almost any angle.

5. Should I buy an EOS R System camera or a DSLR?

"Canon offers a wide range of DSLRs for a wide range of users, and so far just two EOS R System cameras: the Canon EOS R for photography enthusiasts and the Canon EOS RP for those stepping up to full-frame mirrorless. We think the EOS R System is a game-changer for these users.

A Canon DSLR, Canon EOS R and smaller Canon camera.

Mirrorless or DSLR? Which EOS system should you choose?

Professional photographer Richard Walch takes you through the different EOS systems to help you decide which interchangeable lens camera to choose.

"If you're a professional photographer, you might feel there are advantages to a traditional Canon DSLR: a range of proven bodies and lenses to choose from, with all the reliability and ruggedness of the EOS system; high frame rates for fast-moving sports and action photography; predictive AF, which works differently from the EOS R System's AF and might suit some kinds of photography better; a traditional optical viewfinder, which some users prefer for the direct connection it gives you with the scene.

"That said, professional photographers too are adding the EOS R to their kitbags, often as a second camera for situations it's better suited for – where they want, for example, to take advantage of the outstanding RF lenses or the EOS R System's revolutionary low-light performance, or the totally silent shutter, which makes it possible to shoot in previously tricky situations...

"Canon offers both solutions. What is the right choice for you will depend on a whole range of considerations and what are the most important factors for your particular needs."

6. Can I use my existing lenses, flashes and accessories with EOS R System cameras?

"Although it's revolutionary in many ways, the EOS R System builds on Canon's 30-year EOS heritage. We recognise that many photographers and filmmakers will have a substantial investment in EF and EF-S lenses, and you can use these lenses on EOS R System cameras with absolutely no loss of quality or functionality, using a choice of EF-EOS R mount adapters.

"With the standard Mount Adapter EF-EOS R you can use your EF and EF-S lenses on EOS R cameras seamlessly. With EF-S lenses, which are designed for EOS DSLRs with the smaller APS-C sensor, you'll get cropped images that match the smaller image circle of EF-S optics.

"The Control Ring Mount Adapter EF-EOS R adds a lens control ring, which is easy to use without taking the camera from your eye. This offers tactile manual control over various settings, just as you get on the RF lenses – you can customise it to adjust aperture, shutter speed, ISO sensitivity or exposure compensation, as you prefer – so in this sense it gives you the potential to get even more out of your existing lenses.

"Alternatively, the Drop-In Filter Mount Adapter EF-EOS R adds the ability to use drop-in filters, removing the need to fit filters on the front of a lens, which is especially useful for wide-angles with a large front lens element. It’s available with either a variable neutral density filter or a circular polarising filter."

A photographer changes lenses on the Canon EOS R.
It's straightforward to use your existing EF and EF-S lenses with the EOS R System, as Canon Ambassador Brent Stirton found on his demanding five-day trip capturing the wildlife, landscape and people of Namibia.

"Whichever of these adapters you choose, your EF and EF-S lenses are fully compatible. I think technically there is one lens that loses function – a Canon 35-80mm Power Zoom lens that was available in around 1990 for about a year. The lens will autofocus and exposure is all the same, but the power zoom won't work.

"As for accessories, because the EOS R has different dimensions from other EOS cameras, it has its own model-specific Battery Grip BG-E22 for extended shoots. But it's part of the EOS family, so your Speedlites will all fit, and you can attach it to standard tripods and so on. It also uses the same LP-E6N lithium-ion battery as the Canon EOS 5D Mark IV and Canon EOS 6D Mark II.

"The more compact EOS RP uses the same LP-E17 battery as the Canon EOS 750D and Canon EOS 200D."

7. Are there limitations to shooting video?

"We think filmmakers will love the EOS R System just as much as stills photographers. It offers stunning 4K video recording, and there are a host of creative movie-making features. You can control focus with great accuracy thanks to manual focus peaking, face detection and eye-detection AF, and the Dual Pixel CMOS AF allows you to move your point of focus smoothly and precisely using the touchscreen for professional focus pull effects.

"Even if you're shooting handheld, advanced Digital Movie IS provides 5-axis image stabilisation for beautifully steady footage. Using an external recorder, filmmakers have the option of uncompressed HDMI output complete with timecode (YCbCr 4:2:2, 8-bit from EOS RP and 10-bit from EOS R) for professional standard quality and grading possibilities. On the EOS R you can record using Canon Log for up to 12 stops of dynamic range at ISO400, allowing post-production grading to extract every subtle nuance of colour and detail in shadows and highlights, and the EOS R also offers high frame rates up to 120p in HD. It's a highly accomplished filmmaking tool.

"Naturally, you're not going to get every feature and function you'll find on a professional Cinema EOS camera, but professional workflow features such as 10-bit output and Canon Log make the EOS R ideal for use as a B-camera on large-scale productions where you need a compact and flexible tool."

Diagram showing the EOS R control ring’s communications.
The innovative control ring on RF lenses gives you a versatile additional way to adjust various settings.
Nicolai Briz holds the Canon EOS R ready to video.

EOS R first impressions: videographer Nicolai Brix’s perspective

The Danish videographer and photojournalist Nicolai Brix was the first filmmaker to try shooting video with the Canon EOS R system. Here’s what he thinks.

"There's a lot of discussion online about the 'crop factor' when you shoot 4K video on EOS R. The lens's field of view is cropped by a factor of 1.74. So where the maximum 16:9 still image you can capture on the sensor is 6,720 x 3,776 pixels, the 4K video is a slice in the centre of that, 3,840 x 2,160 pixels. Let's be clear: this is 4K resolution, but the complaint is that this is not using the full field of view of the lens.

"This is down to the technical limitations of the sensor and the image processor. We could have tried to pursue full-frame 4K video capture, but it would take a lot of processing, for example, to scale and resample the capture, and this would risk causing the camera to overheat and shut down prematurely during video recording. We didn't want to risk that sort of instability. With the hardware we had available or in the pipeline, this is the best balance we can achieve at this time to deliver 4K capture.

"Another video limitation people comment on is the maximum record time of 29 minutes 59 seconds. This is common in video-capable stills cameras, and it's because of WTO tax rules: any device that records for longer than this is classed as a video camera and taxed at a higher rate."

Photographer Katya Mukhina crouches low to photograph a couple.
Canon Ambassador and destination wedding photographer Katya Mukhina, on location in Iceland with the EOS R System, took advantage of the vari-angle screen to shoot from interesting and unusual angles.

8. Why have you added new features such as the multi-function touch bar and removed familiar features like the AF joystick?

"Designing a whole new camera gives us the opportunity to try different ideas. Some people love the multi-function touch bar on the EOS R, which you can customise to control functions such as AF or ISO setting or white balance. It’s similar to the familiar EOS control wheel, but with the added benefit of silent operation and enhanced weatherproofing. But we're aware that some people really don't like it. Other innovations like the customisable control ring have been pretty universally well received. So has the touchscreen AF system, which really gives you much better control than a joystick – can you imagine trying to use a joystick to select between 5,655 AF points, as you can on EOS R (or 4,700, as on EOS RP)?

"It's about offering the best usability we can for the features available. We tried to balance the new features and functions with familiar EOS handling, menus and so on, so you don't need to grasp a whole new system and can get up and running as quickly as possible. We won't always get the balance right, and we always welcome feedback."

Diagram showing the Canon EOS R’s weather sealing.
The Canon EOS R benefits from the same professional level of weather sealing as other cameras in the EOS family.

9. Why aren't there two card slots, or a higher frame rate, or in-body image stabilisation?

"We totally understand why professionals value dual card slots. The Canon EOS-1D Mark II was the first camera with dual card slots. We know some people find it important for backup, or a more flexible workflow, or simply a feeling of security just in case. In the EOS R it was a balance, for the target market. When we design cameras, we tend to be looking at who the customer is for that product, and what they want. That's our starting point. So we'll put some features in and leave some features out, based on what the customer requires, rather than trying to cram everything in.

"The problem with the EOS R, really, is that it's got such a good feature set, it's appealing to people who are more advanced than the users it's actually aimed at. Professional wedding photographers, for example, want to use it for their work, because it's so compact, offers silent shooting, and so on. And it's great for that. But the EOS R is designed for the photography enthusiast, and it doesn't offer everything you'd find in a top-of-the-line professional camera. As we expand the EOS R System range, we will doubtless add features and functions that best serve other markets.

"When it comes to in-body image stabilisation, let's be clear: the EOS R System does have tech built in like 5-axis Digital Movie IS, and the EOS RP offers a powerful Dual Sensing IS system that reduces camera shake for handheld photography. We get where it is most useful. It's technology we understand. But for stills photography, our view is that optical stabilisation is still superior. If you look at all manufacturers' long lenses, guess what, they've all got optical stabilisation. As we look to the future, we are quite aware that there are potential gains to building in various technologies, and the EOS R System will, I'm sure, continue to evolve."

A photographer holds a Canon EOS RP up a mountain.
The lighter, more compact Canon EOS RP is ideal for travel photography. It has a familiar mode dial on the top.
A photographer uses the Canon EOS R’s multi-function touch bar.
The Canon EOS R introduced innovative controls such as the multi-function touch bar on the back, and has an OLED panel on top that displays current settings.

10. What's the difference between the EOS R and EOS RP?

"The Canon EOS R is designed for photography enthusiasts. The Canon EOS RP is a smaller, lighter camera aimed at advanced amateurs looking to take a step up to the full-frame mirrorless EOS R System. It is the lightest full-frame camera Canon has produced, making it ideal for travel, landscape and portrait photography and videography, or indeed any kind of creativity on the go.

"Some of the differences between the EOS RP and the EOS R are related to the EOS RP's smaller size. The vari-angle touchscreen is slightly larger on the EOS R, has a higher resolution, and offers a higher number of selectable AF points (although the 4,779 on the EOS RP is still phenomenal coverage compared to the rest of the industry). The EOS R's larger body means a larger battery and therefore greater battery life than the EOS RP.

"Other differences arise because the EOS R is designed for more ambitious users. So it has a sensor with more megapixels, and it supports advanced features such as High Frame Rate movies, 10-bit C-Log output via HDMI, and Dual Pixel RAW. The EOS RP also doesn't have the EOS R's multi-function touch bar or an OLED display panel on the top of the body; instead, the EOS RP has a more familiar mode dial.

"On the other hand, the EOS RP introduces some exciting features for the first time, such as focus bracketing, and Eye AF while continuous focusing in Servo AF mode (now also available for the EOS R with the free Firmware 1.20 update). It also offers slightly different Picture Styles and AF mode options.

"For more details, read our head-to-head comparison of the essentials, or see the complete specifications of the EOS R and EOS RP."

كتابة Alex Summersby

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