April-June 2019 issue, Michael Burnhill, European Technical Support Manager at Canon Europe, told us what the new EOS R system means for the future of Canon EOS cameras and hints at the exciting optics made possible by the new RF lens mount.
Interview by Angela August, Editor
AA: Where is Canon heading with the EOS R system?
MB: That's still to be defined, but the plan is to develop the system in both directions. With the EOS RP we've gone towards an entry-level full-frame camera, which is a very large market. It was a bit of curve ball because everyone seemed to have expected a high-end model.
When you have a high-end product it's got to be bullet-proof. It's got to work. That's the faith professionals have in Canon. It’s not going to let them down. And that's what has built the CPS [Canon Professional Services] reputation. It’s the same with a pro mirrorless camera – it's got to work. It can’t be a ‘work in progress’ kind of product.
In the middle market there are users who are passionate about photography, but they don’t want to be overloaded. It’s not about cramming in lots of features that aren't relevant to that user base. Other important issues are usability and practicality. Canon’s menu system is consistent across anything from an EOS 1300D to an EOS-1D X Mark II.
AA: Having said that, the touch-sensitive multifunction bar on the EOS R is a significant departure from the familiar Canon layout. What has the feedback been?
MB: It's been mixed. People either love it or they hate it. It's maybe a bit too sensitive for some people, but it's very customisable. Other people find it fantastic that you've got three functions in one small area.
The touch bar is an interesting story. Canon is changing how we work internally in Japan, and we're now giving engineers sub-projects to work on. So the question was – we can't have a big control wheel on the back any more, but we want to be able to feature some of those controls, so what can we do? An engineer came up with the touch bar because, by using that small control you can carry out similar functions as with the wheel.
AA: EF lenses have eight contacts on the lens mount, while RF lenses have 12. What sort of additional features does this offer?
MB: The whole communication system in the RF mount has been designed with future potential as one of its core requirements.
When we introduced the EF mount there were so many things we weren't aware of; IS was still a dream; we didn’t even know what digital was. When we were designing the RF mount, the future is also unknown, so we needed to plan ahead.
Some of the contacts on the RF mount we're not actually using today. They're for future expansion. But there's a higher-powered delivery system, so we can deliver more power to the lenses, which could mean a bigger motor for faster autofocus (AF), or a power zoom. All these things are being built into the interface from day one, to allow for expansion. What that expansion is we don’t know. We’ve still got to work out what the next 30 years hold for us. The important thing is to lay down a solid foundation so that we can adapt to future demands.
The mount size – 54mm – just happens to be the same size as the EF mount, but we did try other mount sizes. We built prototypes and tried lots of crazy things to see what would happen. But 54mm gave the best balance, allowing us to position the optics any way we want.
So then the question is, why a flange distance of 20mm? Slightly smaller would have given better possibilities optically, but that means the whole front panel becomes thinner. You have to make the camera thinner and smaller, therefore the front body has less strength, and because you have to use thinner metals, the screws that hold it in have to be thinner. All these things then affect durability and endurance. And if you want to hang a big lens off the front of it, you've got to have a solid front panel, with big screws that keep everything in place. So it's that balance of endurance and durability versus optical performance.
We've got the EOS M, which has a flange distance of 18mm and a smaller mount – so we had an example of a smaller mount and a shallow body depth. We had this as a reference point and tried different lens designs to see what would happen. It was a bottleneck for the future. If we wanted to use very wide aperture lenses, etc., they weren’t going to be possible on that sort of mount.
AA: There are currently four RF lenses, with a further six recently announced, but let’s not forget that the EOS R-series cameras are compatible with Canon’s range of over 160 EF and EF-S lenses. Are there any differences in terms of performance when using EF and EF-S lenses on EOS R cameras?
MB: No. For the RF protocol there are different channels. One is for the lens to talk straight to the camera, so if you're zooming, etc, they’re communicating. And then the mount adaptor has a different channel, so it doesn't interfere with any signals. Once the camera detects an EF lens, it swaps its protocol from RF to EF. It's actually using the same protocol as an EOS 5D Mark IV with the same lens.
I can’t talk about exact speeds, but if you go back to the EOS 650, the communication speed would be comparable to walking, with the 5D Mark IV it would be equivalent to being on a scooter, while with the RF technology it’s equivalent to being on a bullet train. So the speed of communication has been massively improved.
AA: Many of your competitors have introduced in-body image stabilisation (IBIS). Does Canon intend to introduce this technology?
MB: In-camera stabilisation – moving the sensor – is good for wide-angle and standard lenses, but as the focal length increases IBIS becomes less effective. There's a very sharp drop-off. If you look at our competitors, all those who use IBIS still have an optical stabiliser in their longer lenses.
We want our own IBIS system, but there are a lot of patents to work around, and we still think optical is the ultimate solution, though both could be used together for greater effect.
There is a high demand for IBIS, but we want to make sure we get it right. It's on our drawing board, but when, or if, we implement it is still to be decided.
The other thing to talk about is dual sensing. Dual sensing IS does not move the sensor – it is picking up the movement across the sensor. It detects low-level vibrations, such as the photographer’s breathing, that the gyros in the optical IS cannot detect. So in practice this gives about five stops correction.
AA: You mentioned that Canon wants to address the movie capabilities of its EOS cameras, but there has been criticism that the EOS RP is lacking some fairly standard movie features.
MB: It’s to keep the costs down. There is a limit to how much data the DIGIC processor can handle in the time available. The concept of the EOS RP is an affordable full-frame model with movie capabilities that we believe are at an acceptable level for customers looking at an entry full-frame model. While it does offer 4K movie recording, some other options are limited because of the additional heat generation caused by greater movie processing requirements. So it's down to the processing power of the hardware used in this price range.
Some of those features need certain technology, and that technology needs either a faster processor or a more expensive part, which affects the price. And then you've got a very different product from where you started.
So, in theory some of the criticisms could have been tackled, but suddenly you've got an EOS R again, and you're back to the same price point, while you were aiming at something different. So there have to be some hard decisions – this is the market, this is what's important, can we meet those goals?
AA: Will Canon be introducing more DSLR cameras?
MB: Yes. Canon still sees demand for all sorts of cameras – including DSLR and mirrorless – so we will continue to produce across multiple product lines. We've only just phased out the EOS-1 film camera because there were still people buying it in certain markets, and we will see the same with the DSLR cameras.
There are certain technologies where we don't think mirrorless is quite ready – the electronic viewfinder for instance – compared to the SLR system where there is zero lag through the viewfinder.
AA: And what is the future for the M-series, which has been a big seller in Japan, but has not done so well in Europe or the USA?
MB: Again, the M-series has still got legs to it. There are so many different types of customers – in Asian markets, they tend to want those smaller cameras, but the Western market tends to want slightly larger cameras. This is where we see cultural divides, so we still see a potential market for this product.
AA: Which brings us onto APS-C with the R system...
MB: Yes, the system could support it, but again it's not a priority because we have the M, and what we need to fill out is the lens range for the EOS R full-frame.
AA: The six proposed lenses have no prices or availability. Can you give us more details?
MB: One of the criticisms with our EOS R was lack of a roadmap. Canon has not really done a roadmap for lenses since 1987 because we've had such a large range. But people were anxious about where the RF lens range was going, and they were confused by the four lenses we launched. These are basically statements to demonstrate what the mount is capable of. For example, the RF 35mm F1.8 Macro IS STM is smaller than the EF 35mm f2 IS USM, but it has stabilisation, macro, lower price… And that demonstrates the ability of the RF mount – to make cheaper, high performance lenses with more features than your existing DSLR lenses.
We have the RF 24-105mm F4L USM, which is smaller than the existing EF 24-105mm f4L IS II USM, but again, superior performance. Then you have the RF 50mm F1.2L USM, which is a super high performance lens that no one else has. The RF 28-70mm F2L USM is a lens no one else can do. The RF mount allows us to do this. If you want to make this on another mount, it would weigh an additional 500g and you would have a filter diameter of 122mm.
There's a strategy behind it. You can’t launch a new mount and say it’s the most amazing thing ever, without launching some exciting new lenses at the same time. We wanted to show that we are committed to the R-series. We're trying to build confidence that the EOS R range and RF lenses are expanding.
There are fewer limitations on lens design; with the RF mount the rules of what we can do, or what we can't do, have disappeared. It was very hard to make a fast-aperture super-wide zoom because the flange back distance on an SLR is greater and you had to have a retro focus design, which meant a whole series of optics that you had to put in before you even started on a design – that's gone. The designer has a blank canvas.
There will be more EF lenses, but probably not until next year. This year we've really got to fill out the RF system. We can only develop a certain amount of lenses a year, so you have to make a choice. The EF range is extensive, so we're really going through that refresh period where some of the older lenses are being updated, while occasionally introducing new lenses, like the TS-E 135mm f4L Macro.
AA: Can you tell us more about focus bracketing? Why did you decide to introduce it into the EOS RP?
MB: We had focus bracketing in the compact cameras, but it wasn't popular and it disappeared. But now macro photography is very popular, and this technique gives greater depth-of-field. It wasn’t really possible with the EF mount. It's all about driving the motor to micro steps and there just wasn't the necessary control.
Some features we see in the RP just weren't ready in time for the R – features such as continuous silent shooting and continuous eye tracking. The continuous silent shooting is now available as a firmware upgrade on the R, but we are working on the Eye AF, so it will be similar to the RP. That will be sometime in the first half of this year.
AA: What other camera features are available on the R range that you couldn't incorporate on a DSLR?
MB: First, you’ve got the dual sensing IS, which I mentioned before. Then, going back to movies, we have a new aperture control mechanism in the system. If you zoom with an EF 24-105mm f4L lens when shooting movie, you can get a pulsing effect because fixed aperture lenses aren't really fixed aperture. There are two aperture systems and they work in tandem – as you zoom they switch from one system to another. There's always a small delay and that's why you get this slight jump.
With the RF system, the speed of communication is very fast and the apertures are working in real time, so you don't see the change in exposure. Even though mechanically things are moving around, it's instantaneous because of the speed of communication.
You get no pulsing because we can adjust the aperture in much smaller increments as well. There is a slight change – around a tenth of a stop – which the human eye does not register.
It is technology that we're incorporating to make these products better for movies. Shooting movies with a still camera you'd lock the aperture down and try not to zoom, to work around the issues. Now, you can treat the R-series cameras the same as a movie camera.
Then there is the Digital Lens Optimizer (DLO). It needs information about focal length, aperture, focusing distance, and with the EF system it was just too slow. That data came through after the image had been taken. You need to have that information as you're taking the image.
The R system allows us to put all the information in the lens chip, so the lens is telling the camera in real time the focal length, the focusing distance and aperture. All this information is fed to the system in real time. When you take the image the correction system gets the image data and the information to correct it simultaneously. So DLO is turned on as standard in the R-series and you don't notice it's turned on at all, whereas on the EOS 5D Mark IV, for example, it slowed the shooting speed down to 1fps (frame per second) and reduced the buffer capacity.
AA: You have talked about how the speed of information passing from camera to lens is critical, so presumably the disparity in performance between Canon lenses and third-party lenses has increased with the R-series?
MB: For an RF lens, yes. But one of the wonders of the system is it speaks the two languages – RF and EF. The camera will know that a third-party lens is not an RF lens and will switch to the EF protocol.
Magnesium alloy was used for parts of the EOS R and RP camera bodies, similar to pro models, whereas, for example, the EOS 6D Mark II uses aluminium. Was this a weight issue?
Weight, but also heat. Magnesium is a better conductor of heat than aluminium, so it becomes like a heat sink. And magnesium alloy gives strength, as well. We talked about durability and attaching big lenses. We could easily have used aluminium and made it slightly cheaper, but the magnesium alloy enables the R-series to perform better.
AA: What do you think is the most significant aspect of the new design?
MB: Its potential. The R-series has so much potential. The RF mount came from a separate project – it wasn't about making a mirrorless camera, it was about the next 30 years. What does Canon need to do to make better lenses? It was all about what was holding us back and what we can do about it. It could have been a new super-processor or something like that, but then we developed this mount which would open up all these possibilities, and then, because we ended up with a 20mm flange back, mirrorless was the solution. It wasn't like, ‘Let's make a mirrorless camera, and then design a mount for it.’ The mount came first.
AA: Do you see a full-frame camera coming in at a price below the RP?
AA: And a pro version before the 2020 Olympics in Tokyo?
MB: Well, that's the million dollar question…