Interview: Understanding RF, DS and DO - we talk to Canon about its latest lenses

Left to right: Yoichi Sato, Manabu Kato and Shogo Yamaguchi

At the launch of the Canon EOS RP in February we had the chance to sit down with a selection of senior engineers and planners to discuss the R series and its lenses. They talked to us about the RP and the six lenses whose development was announced alongside it, but also gave some insight into where the R series is heading.

• Manabu Kato - Head of EF + RF mount R&D
• Yoichi Sato - EOS camera electronics R&D
• Shogo Yamaguchi - Optical planning specialist

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What's the biggest challenge for Canon over the coming years?

One of the challenges from the lens side is that, obviously we switched mount: we added the RF mount. We've kept the same mount for over 30 years, that was really big, and we kept lens compatibility for a long time. But when we started the new mount had to start from scratch and prepare a lot of new lenses, so that's been a big challenge for us. Of course, it’s very exciting that the new mount opens up whole new possibilities in lens design and expand the boundary of image capture.

How do you prioritize which lenses to develop?

So the idea for the initial four lenses was we wanted to deliver the surprise factor, so we decided to deliver the 28-70mm, as well as the 50mm F1.2, with stunning resolution. That was the concept behind these two lenses.

With 24-105mm we thought it would be the best match as a standard zoom lens to the EOS R camera, and the 35mm F1.8 was supposed to be an affordable and compact travel companion. Those were the concepts behind the four initial lenses.

With the six additional lenses that we introduced as development announcements this time, we believe we will be able to deliver more surprise factors, for some models compactness. These two concepts with the addition of these models.

How have you made the 70-200mm so small?

Canon's RF 70-200mm F2.8 L mockup, alongside the EF version. Although it's not clear from this mockup, we expect the RF version to extend on zooming.

We were actually surprised as we started developing this particular product. The idea is that, with the introduction of the large diameter mount with the shorter back-focus distance, we were expecting it to be more suitable for designing wider-angle lenses, but it turned out to be very effective for designing this telephoto lens.

So this is largely due to the fact we have this new mount: it has become a really big contribution to designing this really compact telephoto zoom lens. So we hope we were able to give more of a 'wow' factor with the introduction of this telephoto zoom lens.

I apologize that this is all we can talk about, as of now, but we hope to talk more about it as we make an official announcement of this product.

It doesn't use a Diffractive Optics design, then?

We decided not to use Diffractive Optics with this lens, this time, but we are working on this particular technology and we are experimenting with different designs and so forth, to see how we can use this DO technology in future.

Can you give any insight into the DS technology?

With lens such as the 85mm F1.2 bokeh is a really important factor, because it's a portrait lens. We really wanted to deliver something that was not possible with the conventional lenses, so we decided to develop this technology of defocus smoothing.

There will be two versions of the RF 85mm F1.2L USM: a 'DS' variant will feature 'defocus smoothing' technology.

The fact with our DS technology is that it's a coating technology, so it's relatively easy to apply this technology to a range of different lenses. This is all we can say at this moment.

There are going to be two versions, does this imply the DS technology is quite expensive?

There's a price factor but, with the DS element it's not the case that it's superior in every way. There's some differences: some challenge in maintaining the illuminance. With transmittance, we lose some light as it goes through the DS element, so that is one difference of having the DS technology. So it's not like one version is obviously better than the other.

That sounds like an apodization effect.

Yes

Some lenses designed to match the EOS R and others designed to impress and surprise, what lenses do you imagine EOS RP users buying?

At this moment, the best match would be the 35mm F1.8 and we believe the 24-240mm lens that we announced will be a good companion to the EOS RP body.

We were able to mount the 24-240mm mockup on an EOS RP body, to give some idea of the size.

One thing that's important about our system is that you can adapt a lot of lenses. Truly a variety of lenses: you can adapt some of the really compact EF lenses, that's an option too.

Obviously we're working on a lot of really compact lenses in the future, so I hope you'll stay tuned to hearing from us.

The pro-level 'L' series lineup looking impressive: how far into the future are you planning?

I'm sorry, the roadmap is all we can say for now. We have a full lineup of what there should be: a full lineup of the RF lenses. And what we do among those lenses we choose which to prioritize, that's the concept of how we decide what to work on next.

With this many professional lenses being announced in 2019, does that mean a body isn't far behind?

All we can say is that we're working on a lot of different types of cameras. I can't pinpoint when a specific camera will come. We understand that expectations are really high.

What are the advantages of the faster communication between lens and body that the RF mount allows?

A good example is that we are working on a combination of optical and body stabilization, working together to give enhanced IS. That would be a good example of being high speed communication system in RF.

We are working on a combination of optical and body stabilization, working together to give enhanced IS

There are numerous things that we will be able to deliver, through the introduction of the new communication system. The combination of RF lens and body, the Dynamic Range Optimizer (DLO) data can be transferred automatically to the body. So users will be able to use in-camera DLO for new lenses without needing to download an update from their computer.

We've previously talked about how we're looking another 30 years into the future. We have to think about what might be possible with another 30 year in mind, we have to think that far into the future. So at first glance this communication system might be too much for what's been made possible, as of now. But we have to look so far into the future that this system has to have a lot of potential.

I think most people now understand how forward-thinking the EF mount was for 1987

Looking back after 30 years of EF lens and mount, we can't help but thank our predecessors for being so forward-thinking: delivering a fully electronic mount at that time in history. We hope we were able to deliver the type of communication system that our future generations of designers, thirty years down the road will be thankful us for being so forward-thinking.

Is there anything else you'd like to tell our readers?

So in terms of the six lenses, once we've launched these we'll have ten RF lens models. I hope we can convince our users we’re serious about this mount, serious about this system.

We hope your readers will understand each of these designs are unique, and are impressive in every way, in terms of the specifications, in terms of the size. I hope your readers understand the potential of the system.

Please don't forget the pro-level camera that you're expecting is on the way

We hope that with the introduction of the RP, the main purpose is we hope we're making full frame more accessible to more people. That's what we're trying to do with this camera. We hope that a lot of beginners in photography will be able to enjoy what is possible with the full frame sensor and we hope to expand the market of full-frame camera, overall.

Please don't forget the pro-level camera that you're expecting is on the way.

Also important, we see people speculating that we're terminating the DSLR or the M-series development. What we can say is that we're developing, simultaneously, multiple DSLR, M-series and R-series models. Our approach is to leverage our lineup strategy but at the same time, we'd like to listen to our customers' feedback and make decisions based on this.

Should we expect to see more lenses like the EF-M 32mm then?

The Canon EF-M 32mm F1.4 is one of the few photographically ambitious lenses available for the EOS-M system.

The reason we launched the 32mm for EF-M came from closely listening to users and what the market was asking for. So we were really happy that we were able to deliver something that a lot of users will be able to enjoy and we're really confident about the performance of this lens.

One of the goals of the EOS RP was meant to be a good step-up for current APS-C users. We hope it's possible for APS-C users to step up to the FF camera market.

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Editor's note: Richard Butler

We conducted this interview a few hours after Canon revealed the six RF-mount lenses it plans to launch in 2019 and, although they wouldn't be drawn on specifics, we did uncover a few interesting details.

The confirmation that the 70-200mm F2.8 won't use diffractive optics was interesting (a Canon patent for an extending 70-200 has subsequently come to light), as was the confirmation that the 85mm DS will use an apodization filter effect to smooth the edges of its bokeh.

Canon has only released a mid-level and entry-level R-series camera so far, but its lineup is awash with pro-focused 'L' lenses.

On the cameras side of things, the interview confirmed what we believed about the RP: that it's a concerted attempt to expand the market to reach a new type of user that wouldn't have previously considered a full-frame camera (and, as a result, a different type of user than the one Sony has already been targeting with its a7 models).

It was interesting to hear Canon confirm that there will be a pro-level camera: something that can be easily deduced from the company's lens lineup, but still good to have confirmed. But it was the statement that Canon is working on a combined in-body and in-lens image stabilization system that most stood out.

Many of these are themes that we took up with Canon when we met them at CP+ in Yokohama. There'll be further insights coming in that interview, in the coming days.

from Articles: Digital Photography Review (dpreview.com) https://ift.tt/2HRWDd1