Thoughts on the Mirrorless Revolution

January 03, 2021  •  4 Comments

A Revolution?

I call it a revolution because I think it is the logical next step in photography.

In the early days, mirrorless was sold as a lightweight and compact alternative to the heavy and bulky DSLR bodies. I saw right away that this was not completely true. While the bodies were indeed more compact and lighter, when you started to attach lenses, and adapters, extra batteries, there really wasn't much of an advantage. Add to that the horrible electronic viewfinders, I figured it was going to be a while before I got my first one. I needed a lot more encouragement.

Why a logical next step? Sensor-based everything! It never made much sense to me to have a metering system, and especially a focusing system, that was not integral to the actual focal plane. Before the technologies were available though, the only alternative was either a dual lens set up of the twin lens era in the late 1920's or a reflex housing like many of us enjoyed during the SLR and DSLR days. They worked and they gave us an identical view of what the film or sensor was "seeing" for the most part. And with mechanical shutters and mirror boxes wearing out and the costs to have them replaced, it was time to remove the mechanical bulk much the way Tesla is removing the internal combustion from the automotive equation.

Not impressed

I held a few of the early mirrorless bodies of several makes and was so turned off by the fake look through the electronic viewfinders. I heard everyone talk about how small and light it was - when paired with their bulky 100-400mm lenses. My prime lens is a 500mm/f4, often with a 2x extender behind it so a smaller body is almost useless to me. In fact, I like a bulkier body to hold. So these early products were duds in my opinion. For a compact and lightweight snap shooting camera, I already had one smaller that would also make phone calls and wake me up in the morning.

The Solution is in the Software

My career at NASA involved developing software for digital imaging. Not the editing type of software like Photoshop, but the kind that is hardware-based and built into imaging systems for aircraft, for real-time processing during poor visibility flying. Our goal was to make the processing faster while making the hardware more compact and energy and computationally efficient. Focal plane processing was our end goal. I retired as the program money dwindled and priorities shifted so I never got to see the end.

The R6 Arrives

Fast forward to 2020 with the introduction of the Canon R6. I had been watching the market for some time but had not been impressed with the offerings. Coming from the 1Dx line and currently shooting a 1Dx MkII, nothing offered me much over what I already had. Finally, the R6/R5 that came out in the summer of 2020 caught my eye mainly because the amazing auto focusing that was now offered in the 1Dx MkIII was added, but expanded to include detection and tracking for animal eyes. The 1Dx MkIII was limited to human eyes.

Why the difference? After a couple of simple experiments, it seems the camera first detects a human face (some of the related work I was involved in at NASA) and then locates the eyes. Same with animals, especially birds (and cats and dogs as well as I have heard). Pattern recognition is an important first step in facial detection software and we are starting to see it in consumer photographic equipment now. Being that my main interest is in capturing wildlife, and the focus on the eye is so important, I was excited to see something that may increase my "hit rate" on my favorite genre of shooting.

So, after watching the roll out of these two products very closely, I decided to get the R6, mainly because of the larger pixels (larger pixels = greater signal-to-noise ratio = better low light performance) and the difference in price. Had I been interested in high definition video or had I not already been in vested in big glass, I would have leaned toward the R5. But coming from an amazing 18MP 1Dx and the even better 1Dx MkII with 20 MP, the R6 was a no-brainer to me. I ordered mine with the battery grip and the Kirk L-bracket, something I like for all of my bodies. There went the compact size and light weight of the R6.

In the Hand and out in the Field

My first impressions with the R6 were nothing short of amazing. My description continues to be that it's a "game changer". The image quality is no less than what I'm used to but the autofocus features make this a must-have camera for almost anyone, in my opinion. In just a few minutes with it in my hand, and with the first short venture out into the field, I couldn't say enough good about the performance and the features, especially for wildlife.


Crude cell phone video of the rear of my camera, showing how the animal eye tracking picked up the egret's eye as soon as it was visible.

Some of you may have seen the cell phone video I shared on Facebook, and in another blog post here, showing the back of my camera, as it picked up and focused on the eye of a preening great blue heron, and then continued to lock in on its eye as it moved. Gone was the need to focus and recompose - for two reasons. Firstly, the focusing area on this camera now has over 6000 locations as opposed to 61 for the 5D MkIv and goes nearly to the edges of the frame! And secondly, the tracking works so well, that all you need to do in most cases is compose your image and let the camera take care of the focusing for you. Those of you using back button focus may even find yourself forgetting to hit the back button because the tracking works so well, you may think it's also focusing for you. I found myself doing that while shooting eagles at Conowingo Dam. Fortunately I realized it early and corrected myself. But you may find that in many cases you can revert back to shutter button focus - Gasp! Yes, this camera is really that good.

eagle landing sequenceeagle landing sequenceThe eagles of Conowingo Dam. An eagle landing at 20 frames per second. The animal eye autofocus detected and tracked this eagle as I followed it through its landing.

The eagles of Conowingo Dam. An eagle landing at 20 frames per second. The animal eye autofocus detected and tracked this eagle as I followed it through its landing.

The only con I can come up with at this point is the viewfinder. While it is so much better than any I had seen of other brands (I admit I have not seen them all) in some cases, it does not render highlights very well. After all, it's an 8-bit jpeg representation of a 16-bit+ real world scene (when you factor in human dynamic range compression). But in most cases it looks wonderful and perfectly natural.

Notable Features

This article would be too long if I were to list all the great features of this body, like the articulating screen that allows you to select your focus point (and save your knees), and the touch screen capability, useful for so much of its operation. But I will go over a few of the features I expect to be enjoying.

Amazing Autofocus!
First of course is the amazing autofocus system. Not only is it fast but it's accurate and it seems to know what I want the subject to be. Only in a few cases have I had to do manual selection. But in a wildlife setting, it almost always picks out the animal, and if it cannot find it's eye, it will place a focus box around its head. I used it for a studio session and the human eye focus was perfect. With multiple people in the scene however, you have to do some manual selection among eyes, but it does detect that there are multiple eyes from which to choose. I did notice something about the way it tracks eyes. It apparently needs to detect a human face first. It's also obvious that this software was developed before the COVID-19 pandemic that has placed so many people behind masks. With a mask on, the subject's eyes cannot be found! Pull the mask down and it instantly find the eyes.

76967696Great blue heron at ISO 12,800. The automatic animal eye detect immediately locked in on the eye even in the low light at f8.

Great blue heron at ISO 12,800. The automatic animal eye detect immediately locked in on the eye even in the low light at f8.

Still use your older lenses
Next is the ability to continue to use your older EF lenses. All you have to do is pick up one of the EF to RF adapters for under $100. This is one of the cases where you are fine to go with an aftermarket product if you are using lightweight lenses since it's nothing more than an extension tube with electrical contacts that pass through it. I got one of the Vello ones from B&H and removed the tripod mount because it was in the way. And since the focusing is all done on the sensor and not by in intermediate set of optics, gone is the need for lens calibration! It worked great but it was rather sloppy when paired with my heavy 500mm/f4 lens and in fact, I lost connectivity occasionally, enough to disable my auto focus and make my image stabilization for haywire.

I ordered a Canon one and the fit was so tight that once locked into place, it feels like the adapter is part of the camera body. And the connection with my lens is much tighter too.

Image Stabilization
Another great advantage of the R6/R5 bodies is that they have really effective in-body image stabilization or IBIS. So even if you have the Canon 400mm/f5.6 lens for example, (a wonderful wildlife lens!) which has no image stabilization built in, once you couple it to the R6, you now have the benefit of the IBIS. And as an added benefit, if your lens does have IS, you now get the benefit of both!

Real-time exposure preview
Not unique to any brand or body but most of the mirrorless bodies allow you to preview the image before you take it. Even the DSLR bodies had that (Live View for Canon for example) but with the electronic viewfinders, it now becomes almost standard that you see what your exposure is before you press the shutter button. This is especially helpful when using exposures outside of the normal, human vision range such as when shooting slow exposures or those of dark scenes at very high ISO vales. Autofocusing with dark scenes is now easier than ever. When shooting with strobes it helps to turn this feature off. Otherwise your scene will likely be dark and otherwise not indicative of your final exposure.

Autofocus Loss at f8
In the lens department, now gone is that nasty minimum aperture limitation of f8. Well, since it's moved to f22, it's all but eliminated. That means that those of you with the 100-400mm/f5.6 lens (or the 400mm/f5.6 mentioned above) can now get the 2x extender and still have autofocus at f11.

Shutter Choices
Next is the electronic shutter. We've all experienced the silent shutters of our cell phones. Well, you now have it with the R6/R5. It so quiet in fact that during high speed bursts you will immediately lose track of how many you have shot. The nice extra is the presence of a real, mechanical shutter. This is useful when shooting under flickering lights and when your subject is moving very fast. I used the mechanical shutter during the studio session I mentioned because there were other lights in the room. And even the mechanical shutter is amazingly quiet.

Battery Life
The battery life on this body is severely underrated. Canon lists it at something like 380 exposures per charge at best. My day on the rail at Conowingo was seven hours long. I had not yet received my battery grip so I was relying on one battery, with ten backups, from my 7D MkII and older 6D, I had amassed. To my surprise, the one battery outlasted me. I shot just over 3400 images and the first battery was still going. Now, with a battery grip holding two batteries, and two backup batteries, I may be on battery overload.

Focus Bracketing
Focus bracketing was available on the R and the RP but it's new to me in the R6. It's simple to set up and perform and after a few minutes of testing, I'm hooked. It allows one to easily take multiple images while the camera automatically moves the focus distance deeper into the scene. In the end, you're able to produce one frame, blended from multiple shots, so you get it with all the sharpest edges combined. Like shooting at f5.6 but getting the depth of field of f64 or higher.

77967796Example of focus bracketing. 50mm at f5.6 with the effect of having shot at f64

Example of focus bracketing. 50mm at f5.6 with the effect of having shot at f64.

Affordable High ISO Performance
Great high ISO performance. This is not new for high-end bodies, but for the first time, it's available to those who don't buy in to the professional level gear. For $2400 for the R6, you're getting essentially the same image quality you can get on the 1Dx MkIII which would cost you nearly $6000.

Support of Multiple Aspect Ratios
For those who do portraiture or who otherwise end up with 4x5 aspect ratio images, there is a nice feature which allows you to see cropping bars inside the viewfinder so you don't compose improperly and end up having to fix the image in post or end up cropping grandma's head and shoulder out of the picture.

cropping in viewfindercropping in viewfinderExample of automatic cropping, in this case 6x6, for an Instagram session.

Example of automatic cropping, in this case 6x6, for an Instagram session.

I used this when doing a recent studio job where the final product was to be on Instagram, with all the images being square. Easy. I just selected the 6x6 (not sure why it's not 1x1) crop and it tossed up bars in my viewfinder, making it easy to see what was going to be in my final product. And although it captured the entire frame, when bringing up the images in my RAW editor (Adobe Camera RAW), it automatically cropped them square for me. All I had to do was slide them around to center them the way I wanted. And since the client also wanted the full frame shots, they were all still there as well. The closest thing I had to this with my 1Dx MkII was an extra focusing screen onto which I had etched lines in a 4x5 aspect ratio.


The mirrorless revolution is less about removing the mirror and so much more about moving the essential photographic processes - focusing and metering - to the focal plane. It comes at a time when additional features can be added to control things that were reserved for the darkroom or the computer desk. At least for me, the time has come for me to start taking advantage of what these newer bodies have to offer. I'm expecting totally professional models to come out soon but it seems the big two (or three) manufacturers are trying to drag some of the old school photographers like me into the market to get a taste of it before the pro models come out, hoping to keep us loyal to the brand. So far, it's working for me.

While the 6D was an amazing body for it's time, being a slight step up in image quality over the 5D MkIII at half its price; the 1Dx was definitely a truly professional body; and the 1Dx MkII was the next step, the R6 has now taken over as my primary body. It's hard to think I've just pushed my beloved MkII into the second slot in my bag. But with all the great features of the R6 and the same image quality, it's not really a tough decision.

Be sure to check out my other blog articles for useful photographic tips and techniques.


Dave Gibson(non-registered)
Great job, Glenn. Really enjoyed.
Laura Vroman(non-registered)
Thank you for such a nice detailed review!
I'm looking forward to using one!!
Keith Gypps(non-registered)
A wonderful in depth report that has got me salivating, i think i might hire once first just to be on the safe side.
Eugene Simmons(non-registered)
Thanks for your field report. I've been considering the R6 and you just sold me on it.
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