Canon EOS R LondonChoosing and buying a new camera – especially when you're considering switching to a new system, like the EOS R – is a big decision, and a very personal one at that. There's no 'one camera fits all' solution, and so you need to be sure that your intended purchase will meet your needs.

That can be difficult to establish sometimes when there's a lot of 'noise' about a new camera, new technology or particular headline features.

The Canon EOS 5DS / 5DS R models were a good example of this – the high pixel count drew a lot of interest from photographers simply because of that one feature, without really understanding the disadvantages of a 50MP sensor. The 5DS-series were intended for a fairly narrow audience, but ended up being far more widely adopted than Canon ever expected. Many people then didn't get the results they wanted, as the camera wasn't a good match for their photography.

So if you're considering the new Canon EOS R full frame mirrorless system and would like to know more about it, Nina has put together some of the most common questions she's been asked so far.

Click on a question to find out more.

Which lenses fit onto the EOS R / EOS RP?

What compatibility does the EOS R / RP have with the wider Canon lens system?

What is the handling like using the EOS mount adapter with EF/EF lenses?

Are EF-M lenses compatible with the EOS R / RP?

Are RF lenses compatible with EOS DSLR bodies?

Does the EF-EOS R lens adapter cause loss of light?

Why did Canon introduce a new lens mount?

What is the battery life like?

How big is the viewfinder, and what is it like to use?

Are there any advantages to an electronic viewfinder (EVF)?

Are there any drawbacks to an electronic viewfinder?

Are the changes you make visible in real-time in the viewfinder?

Is the current Canon EOS DSLR system now obsolete?

Why is the R system mirrorless?

What types of photography are suitable for mirrorless cameras?

Why is Canon not using IBIS (in-body image stabilisation)

What's the menu system like on the EOS R and RP models?

What’s f11 focusing compatibility?

How robust are the R-series models?

What’s FV mode?

RF lenses appear to have no focus scale - why is this?


Which lenses fit the EOS R / EOS RP?

rf24 105 side hiResThe EOS and RP cameras accept the RF lens range, of which there are four currently available, with another six planned for release by the end of 2019. RF lenses fit the camera natively – i.e. without the need for an adapter.

At release, all EOS R and RP cameras are being supplied with a mount adapter – the EF-EOS R – which allows you to fit both EF and EF-S lenses to your R-series camera. This extends the range of lenses available for you to use with your camera extensively, given that there are over 150 different EF and EF-S lenses. The adapter also allows you to use Canon's specialist lenses, such as the TS-E tilt-and-shift and MP-E macro lenses.

Back to top

How will the EF-EOS R adapter affect the performance of my EF and EF-S lenses?

Canon ef eos r mount adapterIf you fit an EF lens via the mount adapter onto an EOS R-series camera body, that lens will work exactly the same as it does on any full frame EOS camera. No quality is lost, nor is any functionality. There are, however, some features only found the EOS R and RP models that will only operate if a compatible RF lens is fitted.

When using an EF-S lens on the EOS R / EOS RP then it also works in an identical way to when fitted to a compatible EOS DSLR camera (EF-S lenses only fit cameras with the APS-C or 1.6x crop sensor). The angle of view that an EF-S lens gives will be the same as on an APS-C model; and when attached the EOS R-series camera will automatically swicth into crop mode to give the right coverage for the lens. Because the image circle is cropped, this does mean that instead of the standard 30.1MP (EOS R) / 26.2MP (EOS RP), the maximum image size is only 11.6MP (EOS R) / 10MP (EOS RP).

Back to top

What's the handling like using the EF-EOS R mount adapter on an R-series camera?

mount adapter whThis very much depends on the lens. For longer lenses like the EF 100-400mm, although it makes the combination a little front heavy – the EOS R-series cameras are not quite as good at counterbalancing the larger lenses – it actually still works and handles reasonably well.

Some of the standard 'kit' lenses – particularly the EF 24-105mm f4L IS USM lens – can feel very unbalanced on the mount adapter, especially when compared directly to the dedicated RF 24-105mm f4L IS USM lens.

Part of this handling issue comes from the internal design of Canon's lenses. EF lenses have been designed with more weight towards the front (because of the historical design limitations of the EF mount), whereas RF lenses have the heavier glass elements more towards the middle and rear, thanks to the new RF mount design and much shorter distance between the sensor and the rear of the lens. The extra space that the mount adapter adds between the camera and lens (around 2cm) undoubtedly contributes to this slightly less well balanced feel.

Back to top

Can I use EF-M lenses (for EOS M-series cameras) on the EOS R / EOS RP?

Unfortunately, the EF-M lenses cannot be fitted to the EOS R/RP nor can the RF lenses be fitted to any of the M series mirror less models.

Back to top

Are the RF lenses compatible with EOS DSLR camera bodies?

No, RF lenses have a short back focus design, meaning that the distance between the sensor and the rear lens element is very short – only 20mm. On EOS DSLRs this distance is 44mm; this means that an RF lens would not be able to achieve focus with an EOS DSLR as the sensor is too far away.

Back to top

Will I lose any light when using the EF-EOS R lens adapter?

No, the EF-EOS R lens adapter doesn't have any optical elements in it and so therefore there is no light loss. In essence it is simply acting as a spacer to allow EF/EF-S lenses to achieve the correct distance between the rear of the lens and the sensor so as to allow those lenses to achieve focus. Plus the mount adapter contains all of the necessary circuitry so that the pins can still transmit all of the normal data between camera and lens.

Back to top

Why did Canon introduce a new lens mount?

3 The Front Body copyThe EOS R mirrorless system is actually more about the new RF mount and the possibilities that this new mount opens up in terms of lens design, rather than camera design. However, the two go hand-in-hand as it's only because of the lack of mirror box and reflex system that the distance between the rear of the lens and sensor can be reduced.

The Canon EF lens system came out in 1987 and has performed incredibly well for over 30 years. However Canon has reached a point where the existing mount, and distance between the rear of the lens and sensor, is actually holding back technology in terms of lens design. Therefore a new mount is necessary in order to continue to develop better quality and more versatile lens designs.

Back to top

What is the battery life like?

The EOS R uses the standard LP-E6N battery that is also used in the EOS 5D Mark IV, 7D Mark II and 80D models (amongst others) – the battery itself has good capacity and performs very well in the DSLR models.

Under Canon's testing standards, the LP-E6N is rated for about 370 shots. In real life shooting conditions, we've been able to achieve around 1000 shots from a single battery with the EOS 5D Mark IV. However, there are lots of factors to consider, including whether you use the viewfinder or rear screen to view, how much you review and zoom into your images, as well as Wi-Fi and GPS usage, which all take their toll on battery performance.

In practise, we're finding that power consumption is about double the rate with the EOS R than with the 5D Mark IV – when using the latter with its optical viewfinder – but in fact performs better than when using Live View constantly on the 5D Mark IV. Expect to use two batteries if going out for a day's shoot (we take three just in case).

The EOS RP is designed to be smaller and lighter and, to help achieve this weight reduction, it uses the smaller LP-E17 battery, which also fits some of the smaller DSLR models such as the EOS 800D. Canon quotes this battery at 250 shots, so you will most likely need three, if not four, batteries for a day’s intensive shooting.

Back to top

How big is the viewfinder, and what is it like to use?

EOS R BCKThe viewfinder on both the EOS R and RP are fairly generous in size, the R's viewfinder being slightly larger than the one on the RP.

The image shown in the viewfinder is very bright and you really do not see the pixels that make up the viewfinder, making it much more similar to a DSLR viewing experience with its optical viewfinder. Particularly in lower light levels, many users have commented on how bright the image looks when compared to the view we're used to through an optical viewfinder. This, combined with both R-series cameras' low light performance, make them attractive if you regularly shoot in low light conditions.

Back to top

Are there any advantages to an electronic viewfinder?

Yes, plenty!

The first advantage is that with an electronic viewfinder you'll see what the final image is actually going to be like once captured. The colour and exposure is accurate, allowing you to see both exposure and white balance errors whilst composing, meaning you can make corrections accordingly until the image looks right.

The second advantage is that if you want to use depth-of-field preview (which needs to be programmed onto one of the customisable buttons), there is no loss of brightness.

If you wear glasses, it’s also easier to view the information through the viewfinder than on the rear of the camera as the viewfinder offers eyesight correction. 

Lastly, you can see the information better in bright light than the rear LCD screen.

Back to top

Are there any drawback to the electronic viewfinder?

The answer here is also yes – if you plan to shoot action, especially if you're panning with your subject, as there is a lag on the viewfinder image. When you shoot there is a momentary passing of the subject, which makes it difficult to follow something fast like a bird in flight.

There is a high-speed display mode which does improve performance, but this feature only works if an RF lens is fitted. Currently the longest focal length available within the RF range is 105mm, making the use of EF lenses essential for action photography, where you're typically using a minimum of 300mm.

Back to top

Do you see the settings (white balance, exposure etc) that you change on the camera in the viewfinder?

Yes, any changes that are made that affect the image are visible in the viewfinder – but only when shooting with ambient light. If shooting with flash, then the camera cannot preview the flash light, and so the final image may look different.

Back to top

Is the current DSLR system now obsolete?

No. Canon plans to continue with its EOS DSLR range for some time to come. After all, it was only a few years ago that the last film model was dropped – and Canon will always continue to meet the demand for product ranges, so long as there is demand.

Additionally, the EF and EF-S lens ranges are extensive, with a number of lenses recently updated to improve performance to match camera capability, meaning that EF lenses will continue to be available for the foreseeable future. Indeed, the EOS RP model is even being sold as a kit with a couple of EF lenses as an option – hardly something Canon would do if that lens system was about to become obsolete.

That said, we may see a slightly slower rate of change for DSLR models than previously seen.

Think of the introduction of the EOS R system as a gradual evolution of the EOS system rather than a radical overnight change.

Back to top

Why R system mirrorless?

EOS RP hands onThe R system is all about making full frame cameras smaller, lighter and more affordable. Previously, the move from APS-C to full frame has been offputting for some people because of the increased weight and bulk. Yet the advantages of full frame are significant – wider ISO ranges with better quality at the higher ISO settings being the forerunner.

The EOS R is significantly smaller than its DSLR counterparts, such as the EOS 5D Mark IV, but is still in the normal price range for full frame models. The EOS RP brings full frame down to a much more affordable level that is not much more than advanced APS-C models such as the 80D, and the EOS RP is in fact smaller and lighter than an entry level APS-C camera such as the 800D.

So the EOS R-series mirrorless camera range makes the benefits of full frame shooting available to a much wider range of photographers.

Back to top

What types of photography does mirrorless work for?

It is fair to say that, at the moment, the R-series cameras are not suitable for everyone, or every subject.

If you shoot lots of action, then although the focusing is very fast, the issues with the viewfinder lag when panning makes it frustrating to use. It's not the ideal camera for subjects like birds in flight, for example.

However, if your subjects are slow moving or static, as in the case of landscapes, city shots, travel shooting, architecture and portraiture, then the benefits of Canon's full frame mirrorless system are significant, especially when coupled with the smaller size.

Back to top

Why has Canon not introduced IBIS (in-body image stabilisation)

Canon was the first manufacturer to introduce image stabilisation (IS) and, right from the start, it was very clear that the best place to put an image stabiliser was in the lens. That way, the stabiliser unit can be designed exclusively for each individual lens and the type of work that it does. Then the lens can cope with a much wider variety of movement and provide a better range of corrections. This is especially important when it comes to longer telephoto lenses where the stabilisation has to offer significant amounts of correction.

True, including image stabilisation in-lens will increase the cost of every lens. We would argue that it’s better to pay slightly more and have a system that works optimally, rather than save a little and have a system that is always going to be a compromise.

It's conceivable that virtually every lens in the RF range will have image stabilisation as standard, as it's now very much a mainstream feature.

That's not to say that IBIS won't come – and Canon has told us that it's something that's being worked on at present. However, Canon's lens image stabilisation is second-to-none and performs brilliantly.

Back to top

What menu system is on the EOS R and RP models?

EOS RP menu screenThe menu system on the EOS R is very similar to the system found on most of the other current EOS DSLR models, meaning that it will be fairly recognisable and intuitive when you first pick up the R. As with most current cameras, the touchscreen makes the larger menu systems easier to navigate.

There is, however, no such thing as a standard Canon menu and you will find that many items have moved position, with new menu items added too!

Back to top

What’s f11 focusing compatibility?

The EOS R and RP offer f11 focusing compatibility – this means that the cameras can use Extenders (Canon's name for teleconverters) with compatible lenses and still retain autofocus when the light loss will bring the resulting aperture down to f11. The 1.4x Extender loses one stop of light, whilst the 2x Extender loses two stops of light. Therefore, a 1.4x Extender fitted to a lens with a widest aperture of f5.6 will give an aperture of f8. A 2x Extender used on the same lens will give aperture of f11.

That's what is meant when saying that the EOS R system has f11 focusing compatibility – it's the ability to retain autofocus at an aperture of f11 when used with certain accessories like Extenders, thereby increasing Extender compatibility and performance by one stop more than is possible with any of the DSLR cameras.

Back to top

How robust are the R series models?

RP rigidity wh en copyThese EOS R-series models are designed to be very robust: the EOS R is comparable in terms of its build to the EOS 5D Mark IV. Even with the smaller build of the EOS RP, the sturdy magnesium alloy chassis and weather sealing mean that it will be on a par to the EOS 6D Mark II or 80D.

Back to top

What’s FV mode?

FV, or flexible value mode, is the first new Creative Zone exposure mode (i.e. a mode that offers manual control) to be introduced in over 40 years. Flexible value mode does as its name suggests – it offers flexible control over all your exposure settings, whether you want to control aperture, shutter speed and/or ISO or leave any combination of those settings on automatic. This means that the one mode can mimic Program, TV, AV and even Manual mode.

It's hugely versatile and being able to switch individual exposure controls on or off without the need to change mode is fantastically powerful.

FV mode does take a bit of getting used to, however once you’ve mastered how the options are set it’s a very versatile mode leave your camera on. We think this new mode is here to stay, and in a few years we'll wonder how we ever lived without it!

Back to top

The lenses appear to have no focus scale - Why?

When redesigning the lens system Canon has taken a look at each and every element, and the focusing scale has been moved into the viewfinder, or it can appear on the rear screen.

This does mean regardless of the level of the lens there will be focusing scale available to see. This needs to be turned on from the setup menu. The option where this setting is found is called shooting info display and the scale is turned on by going to the focus distance display, when you can choose to have it always, only in manual focus mode or when focusing and you can choose whether to have the units in feet or meters. For those that like to manually focus there is also a focus guide which will show how much you’re in or out of focus as well as the more traditional focus peaking settings are normally found on mirrorless models.

Back to top

If you decide to take the plunge with Canon's new EOS R system, and need some dedicated tuition to get up to speed with your camera, look no further than our Optimise your EOS R / RP classroom course.