Products >> All Products In Focus: EOS R- Part8

EOS R Specs and What They Really Mean


5,655 AF positions, ability to focus in conditions as dark as EV-6, AF acquisition in 0.05 seconds…the EOS R's specifications are much emphasized, but do you know what they truly mean? In this article, we seek to unravel these specs and through them, understand more about the EOS R and find out just how revolutionary it is.

EOS R hero image


1. 5,655 AF positions

Why is it possible with Dual Pixel CMOS AF and not conventional phase detection AF?

While conventional phase detection AF is known for its speed and accuracy, it does have its limits. 

Conventional phase detection on DSLR cameras: AF points are fixed

During optical viewfinder shooting on DSLR cameras, conventional phase detection AF is carried out by a dedicated AF sensor. This AF sensor is equipped with a number of phase detection sensors that form AF points. The position of the AF points is fixed, which means that depending on the number and type of AF points on the camera model, there may be AF "blind spots" where there is no nearby AF point to provide focusing information to the camera. This makes it more difficult to establish AF on some parts of the scene than others.

Conventional phase detection in mirrorless cameras: Trade-off between phase-detecting pixels and image quality

On mirrorless cameras that use conventional phase detection AF, phase detection is carried out by pixels on the image sensor that are exclusively used for phase detection.

As these pixels cannot be used for imaging, the camera uses imaging information from the surrounding imaging pixels to fill in the information gap. This results in a trade-off on image quality, necessitating limits on the number of phase-detecting pixels. 

Dual Pixel CMOS AF

The Canon-engineered Dual Pixel CMOS AF (DAF) system was first introduced for Live View shooting on the EOS 70D. Since then, it has been implemented for Live View shooting on many of Canon's recent DSLRs, including the popular EOS 5D Mark IV and EOS 6D Mark II. In this system, all the pixels on the image sensor can be used to carry out both imaging and phase detection, removing the trade-off between image quality and the number of phase-detecting pixels.

On the EOS R, DAF is used for both viewfinder shooting and Live View shooting. 

Consider the following:

- There are 30.3 megapixels on the EOS R image sensor. 
- The EOS R has an AF area that covers 88% (horizontally) x 100% (vertically) of the image frame.

This suggests that approximately 26,000,000 pixels (26 megapixels) out of the 30.3 megapixels on its image sensor can conduct AF.

Imagine that: 26,000,000 phase-detection "sensors". This would not be possible if not for DAF technology. 

"AF frame positions" versus "AF points"

When every single pixel can conduct AF, there is a new degree of fluidity that makes the term "AF points" no longer appropriate. Hence, the new term "AF frame positions".

5,655 selectable AF frame positions means that there are 5,655 possible places you can put the AF frame within the screen—i.e, almost anywhere within the AF area. Considering that the slightest difference in focus can change the look of your photo, this also means 5,655 different expressive possibilities. 


Dual Pixel CMOS AF system on the EOS R

A: Selectable AF frames (up to 5,655 positions)
B: Each pixel can perform both phase detection and imaging


2. AF acquisition in 0.05 seconds

The EOS R is equipped with the world’s fastest AF* – the speed of 0.05 seconds is comparable to the blink of an eye. It is the time required for AF to focus from infinity to a specific distance, which is measured based on CIPA guidelines.
*As at 4 September 2018 (according to a Canon survey)


Great for capturing photo opportunities

Such speed gives you a huge advantage especially for photographing subjects with unpredictable movement, such as flying birds, motorsports, or fleeting encounters on the street. It helps to broaden the scope of what you can capture without missing shooting opportunities.

Biker in mid-jump, shot on EOS R

EOS R/ EF16-35mm f/4L IS USM/ Control Ring Mount Adapter EF-EOS R/ FL: 16mm/ Manual exposure (f/10, 1/500 sec)/ ISO 200/ WB: Daylight


3. The world’s first camera** with EV-6 low light focusing capability

Yes, the EOS R can focus in the dark. Just how dark?


What is “EV”?

“EV” is an abbreviation for “Exposure Value”. You might have come across the concept of relative EV when applying exposure compensation. Here, it refers to absolute EV which measures the brightness of the subject at a given ISO speed (usually but not always ISO 100). It is usually determined by a light meter, but it can also be calculated based on the exposure settings that would result in the correct exposure on the camera.

For example, at EV1, the level of light would:
- Be approximately the same as outdoors after sunset
- Result in a correct exposure on the camera at ISO 100, aperture f/1.4 and shutter speed 1 second.


How dark is EV-6 and what does that mean for me?

At EV-6, the light level would be close to pitch darkness. It’s much darker than your usual everyday night photography scene, but the fact that the AF on the EOS R can work even in such conditions means an increased range of possibilities***. It will certainly come in handy when you are waiting in the dark for that wild animal to make its move, or for capturing the atmosphere of indoor parties.
**Fastest among all the interchangeable lens digital cameras incorporating the 35mm full-frame equivalent image sensor with phase detection AF on the image plane (as at 4 September 2018, according to a Canon survey).
***f/1.2, at 23°C, ISO 100, One-Shot AF

Tree silhouette shot at night

EOS R/ RF50mm f/1.2L USM/ FL: 50mm/ Aperture-priority AE (f/1.2, 13 sec)/ ISO 100/ WB: Daylight


Darkness close to EV-6

The actual shooting scene (EV-6) would have looked something like this


4. 40x more processing power

DIGIC is an image processor, but it does not just process image and video data. It also plays a role in key camera functions such as determining the exposure, driving the lens, and performing AF and IS calculations, noise reduction as well as data recording. All that generates a very large volume of data, which has to be processed rapidly and all at the same time. (Find out more in 5 Things Made Possible with DIGIC Image Processor)


The true capabilities of DIGIC 8

The advancements on the EOS R means that even more data has to be processed than before. For example, the amount of AF data that is generated from Dual Pixel CMOS AF is about 40x more than that on the EOS 5D Mark IV (during Live View shooting).

Despite this, the EOS R can acquire AF in 0.05 seconds—the world’s fastest AF for a full-frame mirrorless camera*. Such advancements would probably not be fully realized without the capabilities of DIGIC.
*As at 4 September 2018 (according to a Canon survey)

Location of DIGIC 8 chip in EOS R

Besides processing video image data, the DIGIC 8 image processor on the EOS R also handles many other different processes including lens drive and AF calculation.


5. A native standard zoom lens with a constant f/2 aperture

As implied by its development concept, “Reimagine optical excellence”, the EOS R’s new optical system, i.e., the RF mount and RF lenses, is central to what makes the EOS R so revolutionary.

Of the four RF lenses released alongside the EOS R, the RF28-70mm f/2L USM probably captured the most attention. It provides a fixed maximum aperture of f/2 over its entire focal length range—an eye-opening update because it was a full aperture stop wider that the maximum aperture of f/2.8 on Canon’s other existing constant aperture standard zoom lenses for full-frame cameras.


Beautiful, creamy bokeh that’s great for portraits

The constant f/2 aperture is especially effective for portrait photography. To create a creamy bokeh effect that makes portrait subjects pop requires a fast lens, i.e., one that offers a large maximum aperture. The fastest Canon lenses are prime lenses, and that was what portrait photographers looking for the creamiest bokeh would use.

On prime lenses, it is necessary to change the lens every time you need a different focal length, such as when the portrait subject changes their pose, or when you are switching from a chest-up to a full-body shot. However, for some shooting scenes, such as weddings, every split second where you are not ready to shoot could mean a lost photo opportunity. As a standard zoom lens capable of a very shallow depth-of-field, the RF28-70mm f/2L USM provides a viable, versatile option for such scenarios.

See some examples in:
EOS R: Capturing Compelling Moments in Equestrian Photography


Portrait with background bokeh shot with EOS R and RF28-70mm f/2L USM lens

EOS R/ RF28-70mm f/2L USM/ FL: 70mm/ Aperture-priority AE (f/2, 1/1250 sec EV+0.3)/ ISO 100/ WB: 5200K


RF28-70mm f/2L USM

Besides the RF28-70mm f/2L USM, the RF lens lineup includes another 3 lenses. Two of these lenses support up to 5-stops’ image stabilisation (IS) with the Dual Sensing IS system with built-in image stabilisation (IS): the RF24mm-105mm f/4L IS USM and RF35mm f/1.8 Macro IS STM.


We have unraveled what the high specs of the EOS R really mean. It’s now up to you to make the most of the camera’s abilities!

Find out more about the other features of the EOS R in these articles:
8 EOS R Focusing Features We Can't Wait to Try
Reimagine Optical Excellence with EOS R
An Interview with the Developers: Introducing Canon's First Full-Frame Mirrorless Camera, EOS R
3 Features on the EOS R That Will Change the Way You Shoot


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