Enter the Unicorn. . .trailing clouds of smoke.  (Where there's smoke, there's heat, but more about that in a moment. . .)

Since the beginning of the digital camera era, photographers have complained that, to borrow from Veruca Salt, they "want it now." -- one all-purpose camera that does everything well.  For two decades, digital cameras, especially at the top level, were bifructated into high frame rate, low megapixel sports and action cameras and high megapixel low frame rate studio and general purpose cameras.  This was pretty much dictated by the fixed image processing pipeline maximum capacity available for a given level of technology.  Although pipeline capacity tended to increase over time, for any snapshot in time the capacity was (more or less) limited, hence the tradeoff of megapixels and frame rates.  As a subsidiary consequece, photographers with a wide range of interests often had to purchase two cameras, one of each type, to cover all of their activities.

But, photographers nevertheless dreamed of a camera that could do it all -- the mythical unicorn camera that had both high megapixels and a high frame rate.  Alas, for two decades, in the words of the song, ". . .as sure as you're born, you're never gonna see no unicorn."  This was partly due to the restrictions placed on processing pipeline capacity by extant technology and partly due to the inherent limitations of the digital single lens reflex (DSLR) camera type, a holdover from the film era.

Well, time and technology march on, and those days are over.  With the rise of mirrorless interchangeable lens cameras (MILC) and the inexorable progress of technology, the unicorn camera has finally arrived, in the form of Canon's newly announced EOS R5 MILC -- 45 megapixels and up to 20 frames per second.  With people and animal eye tracking for good measure!  So, just how does it stack up to the previous generation of both action cameras and general purpose cameras?  Let us find out.

A Brief Comparison

For comparison purposes, we'll choose the EOS 1DX Mk III, the latest EOS sports and action DSLR, which is contemporaneous with the R5, and the 5D MkIV general purpose camera that the R5 nominally replaces in the Canon hierarchy.  For the 1DX MkIII, the first frame rate value is for mechanical shutter and the second is for elecronic shutter (ES).  For the R5 the values are mechanical or electronic first curtain shutter (EFCS) followed by electronic.  Note  that bit depth drops with ES, and on the R5, at the highest frame rate (H+).

Undeniably, there are many attributes that matter when choosing a camera.  Use cases are an important determiner, but let us concentrate on camera characteristics only.  These include build quality, functional features and capabilities, ergonomics and customizability, dynamic range, high ISO noise characteristics, color science, and many others.  As the summary table of key metrics above illustrates, and leaving aside the ruggedization aspects, the R5 can compete as both an action camera and a general purpose camera.

With that in mind, let's look at a few specific points that emerge from initial and brief use of the R5.  Note that not all are unalloyed positives -- for instance, optical viewfinders (OVF) still provide a more immediate and accurate view of reality than electronic viewfinders (EVF), although the latter are capable of displaying far more information.  Most DSLRs now provide a live view on the rear screen that can also provide similar information to that available with an EVF -- but in the case of the DSLR one must hold the camera out at arm's length to take advantage of that additional information.

First Impressions

Having said that, here are a few initial observations, in no particular order of importance, and subject to change as experience is gained.  All experience so far is with adapted EF lenses using the control ring adapter.  Lenses include the original 24-105 f5L, 600mm f4L and 2X, 50mm f2.8L TS-E and 24mm f3.5L TS-E.  These findings reflect my preferences and my use cases, and may or may not be the same as others with different viewpoints.

• EVF experience not as comfortable as OVF; however, available extra information and exposure simulation is a big plus

• Despite smaller size, battery grip allows R5 to fit in hand comfortably

• Buttons are very small, joystick on battery grip placed too far down; using with heavy winter gloves may be difficult

• Tiny top panel screen is difficult to use because text & icons are very small

• Image A/D conversion bit depth and frames per second vary depending on continuous shooting drive mode and shutter type: 

  • Mechanical & electronic first curtain shutter (EFCS):  High-speed (6 & 8 fps, respectively) & Low-speed (3 fps) drive modes and 14-bit A/D conversion

  • Mechanical & EFCS with High-speed+ drive mode:  12 fps and 13-bit A/D conversion

  • Electronic Shutter (all continuous drive modes):  20 fps and 12-bit A/D conversion

• Mechanical shutter and EFCS can each impact image quality in certain specific circumstances

  • Mechanical shutter shock can have a noticable negative impact on images at moderately slow shutter speeds, e.g. at and around 1/100 sec

  • EFCS with wide open apertures and high shutter speeds (1/1000th or more) can result in harsh bokeh

  • In fairness, other MILCs exhibit similar phenomena, especially the EFCS impact on bokeh

• Canon C-RAW format reduces file size by as much as 40% with little impact on image quality, mostly confined to raising shadows by several stops

• In-body image stabilization (IBIS) works well, even for older adapted EF lenses

• IBIS and IS always running when using camera with lenses equipped with in-lens IS -- a negative for battery life

• Very complete set of items available for My Menu, but could have used six My Menu tabs vs five available

• Flash cannot be used with electronic shutter

• When using flash with manual exposure and auto ISO, the ISO setting can take on values up to 6400, greatly enhancing exposure flexibility; with previous cameras, when manual exposure and Auto ISO were used with flash, ISO was automatically forced to 400, potentially limiting manual/Auto ISO use in lower levels of ambient lighting and forcing use of Av or another autoexposure mode instead.

• Simplification of AF cases to four is welcome and just as effective as the previous six

• AF with 600mm + 2X on subjects far out of focus is slow or won't budge at all; 1DX MkII is far superior, but in fairness, all mirrorless cameras exhibit this limitation.

  • Setting AF point select to zone and setting the AF-ON botton to enable eye AF allows for quick subject acquisition, followed by eye lockon and tracking.

• While R5 resolution is quite high at 45MP, getting sharp images with the 600mm & 2X extender requires higher shutter speeds than with previous lower resolution EOS cameras

• 600mm + 2X continues to shoot at H+ well below spec value of 60% remaining battery charge and at stopped down apertures, a welcome surprise

• Eye AF is quite effective but is not perfect; it can lose lock on erratic subjects, and sometimes (adapted) lenses cannot drive fast enough to achieve the precise focus point

• Having four dials for aperture, shutter speed, ISO and exposure compensation is fast and convenient; however flash exposure comp. requires more steps

• When using Auto ISO and control ring mapped to Auto ISO, if one exits to a fixed ISO value, the camera will return to Auto ISO only after the display times out; the control ring cannot immediately allow return to Auto ISO

• Files up to ISO 6400 are very smooth and useable, up to 12800 with noise filtering; allows higher shutter speeds

• Images can be cropped significantly while maintaining very good resolution

• Best noise filter approach (using Neat Image) is to perform noise reduction before making adjustments

• Previous cameras varied aperture when bracketing in manual exposure mode and camera exposure steps set to 1/3 stop -- exposure steps had to be set to 1/2 stop to enable shutter speed bracketing with manual exposure; this was an odd design choice since there is virtually no instance where varying aperture is preferable during exposure bracketing.  The R5 performs shutter speed bracketing in manual exposure and 1/3 stop exposure settings, the more useful option in the great majority of instances.

• Fully articulating screen, focus peaking and triangular focus aids are very helpful for getting focus and tilt right on manual focus tilt-shift lenses

• When moving a focus point to the edge of frame, the camera does not allow the focus point to "wrap-through" to the other side of the frame; one must space all the way back across the frame.  While other features make using tilt-shift lenses easier to use, this particular limitation adds unnecessary time to some of the successive approximation methods for getting both focus and tilt set correctly.

• Focus bracketing is an excellent feature, even if DPP is used for processing, although hand-held is problematic for close subjects

• Cold weather performance is an unknown at this point; minimum recommended working temperature for both the 1DX line and the R5 is 32 degrees F.  However, the 1DX MkII was reliable at much colder temperatures, and a favorite activity is photographing birds in the snow as it tends to bring on a feeding frenzy.  We will find out when the snows arrive.

In addition to these points, image quality is excellent.  Canon colors are easy to edit, and dynamic range is increased over 5D MkIV.  With IBIS, image resolution for hand held exposures is visibly better than earlier tripod-mounted 20 megapixel cameras, as observed on the USAF 1951 resolution test chart.  Noise is well controlled, making ISO 6400 a viable setting -- and ISO 12800 available if absolutely necessary via noise reduction filtering, albeit with some loss of faint detail.

Customization

Next, there is the matter of customization.  Each new generation of camera seems to provide more customization options, and the R5 is no exception.  Here, we introduce four categories:  dials, buttons, custom shooting modes and My Menu selections.  Needless to say, customization is a highly personal matter, and likely no two photographers will choose exactly the same setup.  And, one must admit that the settings below are subject to change as additional shooting experience is gained.

Control dials.  The addition of a control ring allows one to use up to four dials for exposure adjustment, each of which can be assigned to one of the five attributes of the exposure pentagon.  The latter term is introduced here in recognition of the fact that the accepted and long standing exposure triangle -- aperture, shutter speed and ISO value -- should for completeness be supplemented with exposure compensation and flash exposure compensation.  With the R5, one can map four of these to separate dials.  In my case, only flash exposure compensation requires additional actions to adjust.  Here are the allocations

• Main dial -- aperture

• Rear quick control dial -- shutter speed

• Top plate mode dial -- exposure compensation

• Lens control ring -- ISO value

Control buttons.  Next, one can map the various camera control buttons to different functions.  After much experimentation, I've settled on the following allocation for certain of the key buttons.  The Q button and the magnify button are unmodified. 

• Set button -- bring up camera menu on rear screen

• AF-ON button -- AF mode toggle (1-shot or Servo)

• Exposure lock button (*) -- Drive mode toggle (single frame, continuous advance, timer, etc.)

• AF point selection button -- Available AF points (e.g. eye tracking, single point, expanded single point, various large zones, etc.)

• Mf-n button -- Custom shooting mode toggle (see below)

• DOF button -- Depth of field (for landscape and architecture oriented shooting modes) or AEL/FEL (for shooting modes that use flash)

• Rate button -- Record or playback sound memo

Note that a consequence of mapping the AF-ON button to AF mode toggle is that it removes the possibility of using AF-ON for its intended purpose, i.e. back button focus, which is normally combined with setting the shutter button to control exposure metering and shutter release only. This is a negative, and has resulted in a need for personal muscle memory retraining.  Pahrenthetically, one might characterize the trio of autofocus mode, drive mode and AF point selection as the operations triangle, a grouping analagous to the exposure triangle, consisting of aperture, shutter speed and ISO.  (Add metering mode -- e.g. evaluative, partial, spot, etc. -- and the operations triangle becomes an operations square.)

Custom shooting modes.  There is also the very useful custom shooting modes feature.  These can be set up to be accessed in a variety of ways.  In our case, as mentioned above, we use the Mf-n button next to the shutter button to toggle through the standard setting and the three custom shooting modes.

With the options available through these four types of customization -- dials, buttons, custom shooting modes and My Menu -- it is possible to set the camera up to be almost an extension of one's image making thought processes.

Bothersome Things. . .or Not

Things about the R5 that bother others, but not me.

• Camera is too big/too small.  Well some like them tiny and light. And some, coming from DSLRs, think tiny is too small for their hands. Personally, lighter is almost always welcome. RE size, the R5, equipped with the battery grip, fits in the hand well but is about as small as I would care for.

• Power switch on left top panel.  This has been a recurrent gripe ever since the original R was launched. All that real estate and nothing but a power switch.  After using an R5 for several months, and given the number of buttons and dials available to be programmed to one’s preferences, to me this complaint is much ado about nothing -- the good stuff is on the right (grip) side, where it belongs.

• Mode button inside mode wheel on right top panel.  Push a button and then turn a wheel to change exposure modes (Av, Tv, M, etc.). Two steps rather than one.  I guess to some people this is a big deal. But, the ability to declare up to three custom shooting modes (to include exposure mode settings) in addition to the regular mode, added to the availability of the mode dial for other functions, e.g. ISO or exposure compensation, is an enormous plus.

• Control ring adapter too close to camera to make adjustments with EF big telephotos.  Well, yes, if one intends to hold the camera with right hand and adjust the control ring with the left, all the while with several pounds of 600mm f4 lens cantilevered off the camera mount. Or if one is constantly adjusting whatever is mapped to the control ring. But, on a tripod it makes little difference. And, if one maps ISO to the control ring and uses Manual with Auto ISO, then that control ring will usually take care of itself.  If none of this is satisfactory, there's always the straight adapter for half the price.

• Overheating in some video modes, e.g. 8K, 4K 120 fps, etc. This is truly a big deal if one bought the R5 for use as a video camera. The camera doesn’t deliver all those advertised "Wow!" video features for more than 25 minutes or so before the laws of physics and engineering catch up.  But then, no one else can do those things without overheating either.  Of course, the other modes work just fine, and one can add an external display and storage mechanism (for an added expense, of course) if one really wants unlimited 8K video.  All that aside, if you don’t care about high end video the R5 is a great stills camera and a fully satisfactory video camera.

• Can’t fully customize every button.  It is true that the rate/record button is limited as to what can be done. And the top panel lock button can't be modified at all. And for the ultra specialized user, maybe even more flexibility could be had.  But, there are still plenty of choices, and I’m just fine with the buttons and dials as they are. I could, however, use one more MyMenu set. . .

• Mismatched card slots.  First it was no dual card slots on the EOS R.  Now, it's the fact that the two card slots aren't identical CFExpress enabled, rather than the delivered one CFE and one SDXC slot.  But, cameras are designed for a price point and a feature set and performance level. Rest assured that there will eventually be a high end R body with two CFExpress slots.  This is not that camera.  (FWIW, sending RAW files to the SDXC card works just fine.)

• Battery grip protrudes beyond left edge of camera.  Of all the complaints, this is perhaps the oddest.  People want smaller cameras.  And they want battery compatibility with pervious camera models.  The latter means keeping the add-on battery grip width roughly the same in order to accomodate the same (dual) battery form factor as previous models.  Which means that the grip has to extend beyond the base plate of the camera on one side or the other.  Better on the left than the right.

No, the R5 is not perfect, especially if any of the above are must haves for an individual.  But for the rest of us mortals, who live in a world where engineering compromises and choices among non-perfect alternatives are a reality, the R5 checks too many boxes to be ignored.

Conclusions

The question initially posed was, can the R5's performance compete with both the 1DX series and the 5D MkIV.  The answer is, of course, in two parts.  First, with respect to the utility of the R5 as a general purpose camera -- portraits, landscape, architecture, etc. -- the R5 is simply superior in virtually every regard, excepting only a mild preference for looking at a scene through an OVF.  But, in the end the EVF provides far more useful information, especially when used with tilt-shift lenses.  The articulating screen, greater customizability, more megapixels, faster frame rates -- the list goes on and on.

Comparison with the 1DX series for action photography is a little more mixed.  The 1DX series does not compromise bit depth at the maximum mechanical shutter frame rate, and it drives focus much better on long telephotos, particularly when used with extenders.  Both are capable of 20 frames per second with electronic shutter(1DX MkIII only).  However, availability of virtually the entire viewfinder for AF, combined with animal eye tracking, is an enormous plus for the R5 -- as is the IBIS and much higher megapixel count of the R5.

None of these cameras is better in all regards, so whichever is picked will be a compromise in some way.  In the end, for action photography it will come down to number of keepers -- images that are well composed (no need to focus and recompose with the R5), properly exposed and, critically, sharply focused.  It will take a while to accumulate enough experience to reach a definitive conclusion, but suffice it to say that initial experience is, while mixed, nonetheless encouraging.  Perhaps the most concerning deficit of the R5 is its inability to rapidly bring a very out-of-focus long telephoto with extenders (e.g. 600mm f4 with 2X) into focus.  Compared to the 1DX MkII, the R5 appears stuck in quicksand, and manual focusing to nearly the subject distance is the only way to get it moving again.

On the other hand, for general puprose photography -- portraits, landscape, travel and the like -- the R5 exceeds the 5DIV in virtually every metric that matters.  In particular, the availability of focus peaking and higher screen magnification for use with tilt-shift lenses is a highly useful time saving aid.  Hand held photography using tilt is often done using an iterative method whereby the lens focus and degree of tilt are repeatedly and alternately refined until sharpness is achieved across the entire plane desired of focus.  Focus peaking reduces the number of steps and iterations greatly, allowing for achieving results not only more rapidly but more reliably and accurately as well.

The ultimate answer may be an expected future R1 professional camera with performance equivalent to the 1DX series and the resolution of a high megapixel studio and landscape camera but with the advantages of mirrorless technology.  We can see the future potential with Sony's new Alpha 1, at 50mpx and 30fps, values that would have been inconceivable even a few short years ago.

To close this out, I didn't forget that opening sentence.  The cloud of smoke allusion refers to early reports of R5 overheating in some of the high end video modes, e.g. 8K, 4K HQ, 4K 120.  These limitations are documented in the camera User Manual, so they were not kept secret -- although more than a few videographers, who perhaps wanted $20,000 dedicated video camera features in a $4000 hybrid camera, have expressed outrage.  To quote Roger Cicala, our favorite lens tester, "expectations are a down payment on disappointment."

We have no such expectations, and for our almost exclusively stills-oriented use cases this camera is indeed the closest thing ever to the long-awaited unicorn.