The EOS R Diary : Customizing Controls

I highly regard the contemporary Canon DSLR user interface design. It provides a great experience out of the box, with just the right amount of customization abilities. The EOS R clearly inherits a lot from this. And it is good. But is also inherits from the PowerShot / EOS M cameras, and from the prevailing over-customization mania, which isn’t.

Late Fall Sunset – EOS R + RF 50/1.2

All three of my current DSLRs (1DX II, 5DS R, 7D II) are configured to have the exact same control layout, so that I can pick any of them and everything is in the place I expect it to be. My goal with customizing the EOS R is to make it as much identical as possible to my DSLR setups.

Please keep in mind that this customization is designed for my still (mainly landscape) photography. I don’t shoot video.

If you haven’t done so, it is now time to read chapter 5 and chapter 7 of the EOS R user manual. I’m not going to replicate what’s there, and how to set the mentioned options.


The mail dial controls aperture in manual mode, as I use Av and M modes 99% of the time, so I prefer aperture to be on the same dial. Its direction is reversed, so that turning it to the right will add more light.

The quick control dial is used to set shutter speed in manual mode. Otherwise it is used to set exposure compensation. Its direction is reversed, too (there’s one setting that applies for both dials). As a side note, I disregard any camera with a dedicated exposure compensation dial that cannot be used for anything else. I’m glad Canon finally abandoned that concept even on the M series.

Feedback to Canon: +/- 3 stops of compensation range isn’t always enough. It should be +/- 5 stops, like on any recent single digit Canon DSLR.

The lens control ring is configured to set ISO, but only while metering is active. The ring on the RF 50/1.2 is a tad too loose to be used without an interlock. There’s one drawback for the latter: auto ISO cannot be set with the control ring this way.

Focus ring rotation behavior (ill-named as sensitivity in the menu) is linked to rotation degree. Honestly, I wouldn’t have bought the camera without this option. I find it totally impossible to manually focus with the rotation speed sensitive behavior.


The EOS R team did a great job with minimizing the number of physical buttons. Well, actually went one button too far with removing seldom used stuff.

I strongly believe that metering and AF should be on separate buttons, so the shutter release half-press only initiates metering on my cameras. AF ON turns focusing on, with a side effect of also initiating metering. But the general idea is to be able to release the shutter without AF, and this configuration makes it possible.

M-Fn have AE lock and hold assigned. Like on all my cameras. This is really handy when shooting frames for a stitched image and want to ensure the same exposure for the entire series, but also enjoy automatic exposure setting to get into the ballpark of the final exposure.

In general, I prefer to place all-point, auto point selection AI Servo AF to the * button, but unfortunately it’s not an option on the EOS R. So it toggles between one shot and servo AF for me.

I configured the AF point button to switch directly between AF methods. This is something I use a lot, and I also limit AF methods to face+tracking, single, expand area (both) and zone AF.

Cross keys are set to move the AF point around, with the center Q/SET button set to reset the AF point position to the center of the screen. The erase button has the exact same functionality, but its way more natural to press the center of the cross keys to move to the center instead of finding another button.

While we are here, there are a few things where I would welcome a change in further firmware releases.

Feedback to Canon: During picture taking the erase button has the fixed functionality of resetting the AF point to the center. This is rather cumbersome, as I described above. Instead, the erase button should have assignable functionality during picture taking, for example one can assign the depth of filed preview to it (since there’s no physical DoF preview button on the camera – the place I think Canon went too far with button removal).

Feedback to Canon: During image playback, every single contemporary single digit DSLR can be configured to use the SET button as a magnification button. I would welcome this option on the R, or at least an option to be able to switch the SET button’s functionality with the magnify button.

The Mosquito Hut – EOS R + EF 35/2 IS

MODE is left at its default function. Let me stop here for a moment. There is sizable hysteria around Canon’s choice of the mode button instead of the mode dial. Well, the MODE button comes from 1-series DSLRs. And it is rather convenient if you shoot tethered. For example you can switch the shooting mode from within Kuuvik Capture. Try to do that with a mode-dial-equipped camera when it is mounted 4 meters high. Yes, I do prefer to have a MODE button.

I’m glad that there’s a video record button, and that I’m not shooting video. This button is a key element of my customization. It’s assigned function is DIAL FUNC. The R lacks the usual camera-top buttons like WB, drive mode, ISO, etc. DIAL FUNC is an amalgamation of those. After pressing the DIAL FUNC button, you can choose between different functions with the quick control dial, as well as different values of the chosen function with the main dial. Up to five functions can be selected for DIAL FUNC. I have ISO (for cases when the attached lens have no control ring, and for selecting auto ISO), drive mode, and metering mode (I usually leave it on evaluative, but there’s no way to set it via the menu).

And finally, the LCD illumination button is used for just that. No inadvertent switching between different top LCD information modes, thank you.

Touchable Thingies

A controversial topic, I must admit. Yes, the M-Fn Bar is a gimmick, and I would prefer a joystick, or button(s) in the same place. Or a button plus a display mode selection switch (more on this in a later post). But touch and drag AF is genuinely useful. Actually so much, that I constantly find myself reaching for the LCD even on the 5DS R and 1D X II…

So let’s see first how I configure touch and drag AF. Positioning is relative, as I wasn’t able to develop a muscle memory for absolute positions. And only the right side of the screen is active, as I want to drag the AF point with my finger, not with my nose.

The M-Fn Bar is arguably a thing that needs to be worked around. It’s safety lock is upsetting, but without it you’ll definitely change settings inadvertently. But there’s a solution! The multi-function lock that I never ever used on any of my cameras before the R. So the LOCK button locks the M-Fn Bar for me (only works during shooting, and NOT during playback, though).

During picture taking, the M-Fn Bar’s assigned function is to zoom in and out on live view. This is a seldom used function for me on a travel camera. And on a tripod, I can safely disengage the lock with no fear to make an uncorrectable error.

During playback the right side of the control toggles between one and zero star rating.


The EOS R is a rather minimalistic camera. This isn’t bad. On the contrary, I enjoy shooting with it mostly because it lets me focus on the bare essentials. I know from experience how much thinking goes into making a camera minimalistic. So hats off for the EOS R team.

But you definitely have to think about your needs and configure the camera for those. The all too common “I want it all, just in case” thinking will not work here.

The EOS R Diary : Whys

This is the first installment of what I plan to be a long(ish) series of posts about my experience with the Canon EOS R system. Yes, while I’m not a big fan of mirrorless in general, I bought an EOS R along with an RF 50mm f/1.2L USM lens. Why?

First and foremost for software development and testing purposes. ShutterCount was the first and as far as I know still the only app that can read the shutter counter of the R (plus the M50). Kuuvik Capture provides tethered shooting support for the EOS R for macOS Mojave users as well (Canon’s own software is not supported on Mojave).

And there’s another reason. I have been looking for a camera system that requires less disciplined technique than my 5DS R plus Zeiss/Rodenstock glass for a very long time. For those occasions where spending half an hour on a single frame isn’t feasible (think travel, for example). What the 5DS R produces is pure magic, but sometimes I would love to stop down beyond f/7.1 or have auto-focus.

November Sun – EOS R + RF 50/1.2

I had tried many options: APS-C, full frame, medium format. From Canon, Nikon, Sony, Fuji and Hasselblad. And they all failed. Either in the image quality department, or I just gave up amidst frustration because of their awkward user interfaces.

Regarding image quality, I look at the whole imaging chain. The EOS R, with the RF 50/1.2 and Capture One as the RAW converter is capable of producing excellent image quality. (Lesser RAW converters, such as Lightroom or DPP, produce lamentable results, so everything I say here refers to Capture One converted files.) No, it’s not in the league of a Zeiss Otus or a Rodenstock HR-Digaron on the 5DS R, but close enough so I don’t regret leaving the big boys at home.

The freedom those larger pixels and AF brings is charming. I do warn people longing for high resolution cameras that it’s hard work to use them properly. The R’s full frame sensor with 30 megapixels is a little more than what I would consider as an easy-to-shoot camera, but still manageable. And the resulting images can be printed quite large.

As you probably guessed, I like the camera. It won’t replace any of my DSLRs, but already opened up new possibilities, and hope it will do even more in the future.

This brings me to the next why.

Based on the exorbitant amount of negativity on the net about the R you may think it’s a bad camera. Well, from my experience it’s clear that, to put it mildly, most of those reviewers aren’t on the top of their craft. And all this darkness irritates the hell out of me. I expect Canon to make the paying customer (me) happy. I don’t care if the professional we-know-everything-better haters aren’t happy.

Each camera offers a feature set for its target audience. If it’s not for you, then move on, choose another one that fits your needs better. Finding workarounds and solutions to make a system a better fit for one’s needs is a sign of intelligence. Yet I seldom run into constructive and helpful writings. The stupid mud-slinging that goes on and on is a sign of arrogance. Honestly, some of those guys should seek immediate medical assistance.

With that said, if I had been in charge of leading the camera’s development, there are things I would definitely have done differently. But as someone who does user interface design for more than three decades, I can understand the motivation behind most of the team’s decisions. And as someone who knows way more about the internal working of Canon cameras than any of the regular reviewers, I’m confident that in the upcoming diary entries I will be able to shed light on the whys of the EOS R.

That’s for the introduction, next time I’ll discuss camera customization. Homework: download the camera’s user manual and read chapter 5 and chapter 7.

Choosing Lenses for the Actus-G

Choosing lenses for the Cambo Actus-G isn’t trivial. Partly because the abundance of choices, and mostly because concrete numbers – based on which one can decide whether a lens will fit – are scarce. With this post I’m trying to shed some light on the problem, provide a few numbers and simple formulas for your own calculations. I’ll illustrate the concepts using large format view camera lenses (the Rodenstock HR Digaron-S 100mm f/4 in particular), because my goal is to use Rodenstock glass with the Actus. But will also mention how things apply to medium format lensboards (such as Mamiya and Pentax).

There are a couple of distances one needs to consider for a given configuration, depicted on the following image (with the bellows removed, of course).

Distances for a lens focused at infinity

Lens flange focal distance at infinity (a). This is the distance between the lens’ mounting flange and the sensor, when the lens is focused at infinity. The lens will not normally come closer to the sensor than this (focusing closer will pull the sensor away from the lens). Data sheets for large format lenses contain this number. For medium format lens boards, this number is the flange focal distance of the lens board’s mount.

Flange to lens end distance (b). The distance from the mounting flange to the end of the rear lens barrel for large format lenses. The number is available from manufacturer data sheets. For medium format lensboards, this is the distance from the mount to the rear end of the board. Unfortunately Cambo does not publish the thickness of their boards, but in general Hasselblad and Mamiya RB/RZ will work with DSLRs, while others require a mirrorless “back”.

Mount holder and mount thickness (d). It’s 11mm on the Actus-G for the AC-78E bayonet holder and Canon bayonet.

Camera flange focal distance (e). The lens mounting flange to sensor distance of your camera. 44mm for Canon EF, 26.7mm for Fuji G, 18mm for Sony E, and so on.

Lens to rear standard clearance (c). This is the important number that indicates whether a lens fits or not.

c = a – b – d – e

If it’s larger than zero, the lens will be able to reach infinity focus on the Actus. A negative value indicates that the lens is a no-go for the given setup (will have no infinity focus, but might work for closeups).

Simple? Well, there’s another caveat. Lens movements and even the bellows need some clearance. On the following image a white line indicates where the lens end would fall with no movements applied.

Clearance required for movements

This clearance depends on the diameter of the rear barrel, and may limit the amount of tilt/swing if (c) wasn’t too large to begin with. 8mm or more for (c) is a safe bet.

The following table summarizes values for Rodenstock HR Digaron lenses. Why those? Because Rodenstock is the only company still in the business of making large format view camera lenses, and because they seemed pretty good from the data sheets (my experience with the HR-S 100/4 confirms this). I assumed (d) being 11mm for Sony E and Fuji G mounts as well.

Using a Sony A7 camera will allow you to go as wide as 50mm (with limited movements) on the Actus-G. But don’t forget that you have shift, so stitching can be used to increase field of view. There’s a way to go wider with large format lenses, and that’s the Actus-DB2 with a digital back (and the associated problems with crosstalk and mazing artifacts with wide angles – a bag of worms I don’t want to open).

The original Actus also had a special rear standard with no rotation and with a fixed bellows that lets you use wides down to 32mm. But as mentioned in a former post, I found the non-geared movements of the original inadequate, and thus skipped that version. The numbers above refer to the Actus-G.

So it’s not a surprise that my first lens is the 100mm f/4. The next one is going to be the 180mm f/5.6, but that presents another aspect to think about. Maximum extension to be exact.

Maximum extension

Theoretical maximum extension (f) is the maximum distance between the lens’ mounting flange and the sensor, with the telescoping monorail fully extended and the focusing mechanism in the farthest position. Naturally it must be larger than (a).

f = monorail_length – 28 + d + e

The stock Actus-G monorail is 152mm long, the Actus-DB2 monorail is 174mm, and there are 300mm and 450mm options.

There’s theory, and then there’s practice. You might have noticed on the above image that the rear standard tilts backward a bit (check the bubble level). This is due to the flex between the monorail and the sliding base of the rear standard, as well as the flex between the sliding base and the focusing mechanism. To avoid the flexing, you want roughly 10mm more overlap between the monorail and the sliding base, and don’t want to pass the 50mm mark on the focusing scale. So the flex-less practical maximum extension is:

f_practical = monorail_length – 50 + d + e

Of course you can compensate for the backward tilt using a front tilt, but the extreme extension pictured above also puts undue stress on the parts of the camera, so I’d recommend to stay within the practical limit.

I bought the Actus-G with the DB2 monorail with the intention to provide enough extension for the HR Digaron-S 180mm f/5.6. In theory, it would allow 201mm, with ~23mm of focus travel over the 177.4mm flange focal distance of the lens. Well, this was before I discovered this flexing. My opinion now is that the HR-S 180 will need the 300mm monorail for better stability. I don’t regret getting the DB2 rail, since it makes my system more rigid with HR-S 100. As usual, stability needs sacrifices in terms of weight and ease of portability.

There is another way to increase extension by turning the swing mechanism 180 degrees and mounting the lensboard to the very front of the camera. It gives 45mm more, but it’s slow and inconvenient to do, and the zero swing marks are a bit off in the reversed position. I’d definitely choose a longer monorail over this. But it could come handy in case of emergency.

Note that you may also need a longer bellows as the 3-fold shipped with the camera extends only 120mm.

— ooo —

That’s all regarding the “which lenses will fit” question. By now you know the requirements and the limits. This is where I stop today, movement limitations with Canon DSLRs being the topic I’m planning to explore in an upcoming post.

Product images were made with a Canon EOS-1D X Mark II and Zeiss Apo Sonnar 2/135 ZE lens. Focusing was done in my Kuuvik Capture app. Guides in Kuuvik Capture came in handy to make sure the camera alignment is square with the Actus.

Rodenstock HR Digaron-S 100/4 + 5DS R Crops

If you were wondering what kind of performance the Rodenstock HR Digaron-S 100mm f/4 lens is capable of with the Canon EOS 5DS R, here are two 100% (actual pixels) crops from my test shoots for your pixel peeping pleasure.

Click the image for 100% view on non-retina displays.

While the sRGB and JPG conversion kills some of the magic the files have, you can still see the stunning resolution and lovely rendering. Both files are straight out of Capture One 10. The lens is in the same league with my high-resolution Zeisses (28 and 55 Otuses, and 135 Apo Sonnar).

Click the image for 100% view on non-retina displays.

Aperture for both shots was somewhere between f/5.6 and f/7.1. The lens and the 5DS R were mounted to my Cambo Actus-G view camera. Focusing and capture was done in Kuuvik Capture.

These crops are from the 5-10mm vicinity of the image center, but you get the same quality to the edge of the 70mm advertised image circle.

The 70mm image circle allows for 15mm shift along the longer image side and 18mm along the shorter. There’s a 12mm-ish practical shifting limitation along the shorter image side with Canon DSLRs, however (more on this in a later post).

You can shift all the way to 22mm the Actus is capable of along the longer side – going well out of the advertised image circle. But you’ll start to lose edge/corner sharpness past 17-18mm. To put it in perspective: with 22mm horizontal shift the corners are comparable to what you get at 12mm shift with the Canon TS-E 24mm f/3.5L II. Impressive. Think about 150-180 megapixel stitches with this shifting potential.