Sometimes you can use past experience to predict how things will behave and preform, but sometimes things change just enough that the only real way to understand the changes is though actual practical experience.

In this episode, I’m talking about my struggle with just that. Mirrorless cameras are just different enough from DSLRs in important enough ways that I’m not entirely sure how that transition will play out in how I shoot, especially when it comes to my wildlife photography.

Compounding matters, my decisions are complicated by design decisions that Canon has made in how their RF 100-500mm f/4.5-7.1L IS USM lens interacts with teleconverters.

One Trouble with Mirrorless

Mirrorless cameras pose some interesting problems for me due to the simple nature of how they work. Since there’s no purely optical path to observe the world though the lens, to do that the camera must always consume power.

For many users, and in really in many cases, this isn’t that big of a deal. The vast majority of the time, the camera is either actively creating an image or is off. However, in wildlife photography, at least the way I do wildlife photography, I spend a substantial amount of time observing my subjects through the lens, ready to shoot at the slightest hint of interesting behavior.

When using a DSLR, this isn’t a problem. With an optical viewfinder, no power is being consumed while you’re just observing. Sure you don’t have autofocus, or image stabilization, but by and large, that’s not a big deal.

On the other hand, mirrorless cameras can’t just sit and observe — well they can, but they consume battery power and generate heat just to show you what the lens is seeing.

While I don’t expect this to be a world ending problem for me. After all there are quite a few wildlife photographers that have switched to mirrorless cameras. I’m also not entirely sure how this plays out either in terms of how I use the camera, and how I have to go about managing batteries in the field.

One interesting side note, that I didn’t mention in the video, and assuming that the details in the EOS R5’s manual is correct, the camera uses less power when the LCD display is being used than the OLED EVF. Typically on the order 30-45%. And in some respects, I’m not totally surprised. The EVF runs at 120 Hz, and is a 2 MP display, while the larger 3.2″ LCD is only a 0.7 MP display, and likely runs at much lower refresh rates.

Granted, I’m approaching this from a niche application. But I think what ultimately frustrates me is that the only way mirrorless cameras really have completely parity with DSLRs is when they have a significant lead in technology. And that only really happens if manufactures decide to completely abandon DSLRs.

Put another way, a hypothetical 5d mark 5 that used the same sensor and processor as the R5, and the AF and metering sensor from the 1DX mark 3, would out preform the R5 in virtually every respect when it comes to power consumption, battery life, and likely thermal performance.

With a DSLR, the complexity comes largely from insuring that the various dedicates sensors are properly aligned. Not from having to constantly process and compute image data to even form an image. Additionally, those specialized sensors for the autofocus and metering systems allow the camera to simplify the processing it has to do to preform those tasks.

And actually, there’s one benefit that I haven’t really seen talked about — though to be honest, I’m not entirely sure how much of a factor it really is either. Canon’s high-end DSLRs like the 5D mark 4, and 1DX mark 2 and 3, have RGB+IR metering sensors. With IR sensitive pixels, the cameras AF systems can use temperature queues as well as color queues for tracking a subject. That is, a bear, or a bird in flight, isn’t going to have the same thermal signature as the trees or terrain it’s moving through, and so the camera’s processor can use that to track the subject across the AF grid, as well as better reject interfering objects.

As things currently stand, no mirrorless camera has IR sensitive pixels — and it would be difficult for them to do that anyway, since they all have IR cut filters anyway unless they’ve been modified for astrophotography work. Therefore mirrorless cameras have to use more processor intensive methods to recognize and continue to track a given subject.

The RF 100-500mm f/4.5-7.1L IS USM and Teleconverters

The second thing I wanted to talk about is the teleconverter situation with the RF 100-500mm lens.

Since the lens has become available, more information has slowly come out on it’s capabilities; though at least as of the time of writing, full image quality tests are still not readily available. Most notably the information came out that while Canon claims the lens is compatible with the simultaneously announced teleconverters, in practice this isn’t quite the case. Or at least, I have a hard time calling the lens compatible with teleconverters.

Specifically, Byian at the Digital Picture in his testing found that you cannot mount either the 1.4x or 2x teleconverter when the lens is zoomed to less than 300mm. Moreover, while the teleconverter is mounted, the lens cannot be retracted below 300mm.

To be quite honest, I’m more than a little disappointed in Canon’s decision here and it’s seriously affected how I’ve had to think about planning out my lens purchases on the platform as a whole — and really throws up some questions again about how to manage moving to mirrorless.

And this honestly gets quite complicated, at least it does to me.

On one hand, the 100-500 gives me 25% more reach than my 100-400 does. Which in theory should reduce the need for shooting with a teleconverter in the first place. While I now frequently find myself shooting at 560 mm with a 1.4x TC, I could accept the loss of 60 mm, or about 9% of the reach, and just shoot at 500.

On the other hand, if I want to put a 1.4x TC on the lens, I go from having a supremely useful 140-700mm range to a much more, for me at least, problematic 420-700mm range.

How do you effectively manage that?

So I think part of the problem here, may stem from the way I view teleconverters and zoom lenses compared to others.

For many, it seems like the thought process is that you zoom all the way to the longest focal length, and then if that’s not enough you put a teleconverter on. This is certainly, for example, how Bryan does his lens image quality tests.

So for example, in his tests of the 100-400, he covers 100-400 mm with the bare lens, then 560 mm and 800 mm with the 1.4x and 2x teleconverters.

For me, I view a teleconverter on a zoom as simply multiplying the focal length of the lens. So mentally it’s not a 100-400 + 560 + 800, it’s a 140-560, or a 200-800.

I’ve arrived at this way of thinking for two reasons. First, in my experience it’s not usually practical be messing with a teleconverter in the field. It takes time, and 3 hands, to remove or install a teleconverter, and they’re easy enough to drop and lose or damage.

With the 100-500’s reduced range when using a teleconverter, it significantly impairs the flexibility that comes with using a super telephoto zoom. In fact, this is one of the primary reasons I prefer using a zoom, like the 100-400, instead of super telephoto primes with better optical quality. I’ll gladly take the hit in image quality to have the flexibility to not have to constantly change lenses.

And this whole point raises some questions in my mind, about how to deal with the 100-500 when you’re using it with a TC, and doing so economically.

With a 1.4x TC making it a 420-700 mm lens, there’s really no a great many options to pair it with.

As things currently stand, the RF 70-200mm f/2.8L isn’t compatible with the RF teleconverters. So it’s not possible to use the 100-500 with a 1.4x and pair that with the 70-200 with a 2x on a second body giving you 140-700 mm minus 400-420 mm.

You could certainly have a second 100-500, but it seems pointless to me to buy 2 of the same lens, just for the case, where you have a TC on one of them.

You could keep using an EF mount 100-400 if you have one. I do, and since I’m not ready to completely convert to mirrorless, I’m going to have that for the foreseeable future too. Then again, I can just use it with the EF 1.4x III, and have a 140-560mm lens and crop to make up the 560-700 mm difference.

700 mm is only 25% more focal length than 560 mm, and with a 45 MP sensor in the R5, I can crop in 25% and still have an almost 34 MP image. Given that the 30 MP from my 5D mark 4s is good enough for great quality prints, that should be a workable solution.

Of course, the extra 100 mm on the 100-500 may mitigate the need for using a teleconverter as often. Then again, in my own personal experience, I’ve always found it hard to pass up having that bit more reach.

In either case, as I’m still waiting for my R5 to ship, I’ve had a lot of time to really think about how I’m going to transition to mirrorless most effectively and economically. While I know I’m coming at this form probably a more niche perspective than a lot of generalist photographers, I see a lot of cases where I’m really going to have to try things out to really understand how the new gear will workout for me in practice.