This is a continuation of a series of posts on the Nikon D850. The series starts here. You should be able to find all the posts about that camera in the Category List on the right sidebar, below the Articles widget. There’s a drop-down menu there that you can use to get to all the posts in this series; just look for “D850”. This is also a continuation of a series of posts on the Sony a7RIII. You should be able to find all the posts about that camera in the Category List on the right sidebar.
We had our children and grandkids at our house over the holidays. It had been a while since we were all together, so I was feeling the need to catch up photographically. I take the pleasant task of documenting some of our family history seriously, and I approached this the same way. But I also had two new cameras, Sony’s and Nikon’s latest take on what an all-around full framer should be, and this was a good chance to use them extensively side by side. I learned a lot, and I’ll tell you what I found. By the way, for the most part, I am not showing you the best pictures, but the ones that illustrate interesting differences. Pictures where the cameras did everything perfectly are not that useful in this post.
But first, a disclaimer. Taking family photos, at least the way I do it, is a moderately specialized activity, so what I’ll be talking about here won’t apply to photography in general. Much of it will apply to event photography – at least the kind with no artificial lighting or light modifiers.
I don’t do posed shots, except the very occasional – and rarely successful – “hey, look at me for a second” kind. I concentrate much more on the kids than the grownups. That means that the action is pretty rapid, and I need to frame and focus in an instant. I use aperture priority almost all the time to handle lighting variations, and on DR-Pix cameras like the a7RIII and D850, mostly use the higher base ISO: 400 for the Nikon, and 640 for the Sony. I use the exposure compensation dial to get the shutter speed I need.
I used to use what Sony calls flexible spot for autofocusing (and I always use autofocus for these fast-moving shots), but Nikon’s and Sony’s face detection is now so good that I use that, gaining a lot of speed in framing and focusing. In the case of the a7RIII, I use the eye-detection for many shots.
I decided to see how far I could get with similar lenses on the two cameras. I put a Zeiss Batis 85 mm f/1.8 on the Sony, and a Nikon 105 mm f/1.4 on the D850. I could have used the Sigma Art 85/1.4 on the Nikon and kept the aperture to f/1.8 and narrower, but I wanted to have a couple of different “looks” available, even if they weren’t all that different. To make the comparison tough, I used both lenses wide open all the time.
Size and weight
The D850 body is heavier than the Sony, and the lenses I favor for the Sony are smaller and lighter than those I use on the Nikon. I think that’s a matter of configuring each body to take advantage of its strengths. The a7RII doesn’t feel right with really big lenses (there’s a grip available that helps there), and feels delightfully diminutive with small, light lenses. The D850 is already pretty heavy, and if the grip weren’t seriously back ordered, I’d be using it with that and heavy, fast lenses.
Throw a 105/1.4 on a D850 and you’re going to impress your friends; the combination screams photographer. With the Batis on the Sony, you’ll have a lower profile. Call that good, or call it bad, depending on your ego and goals.
I have complained long and hard about the Sony mirrorless camera user interface (UI), starting with the NEX-5 and NEX-7. There was a noticeable improvement with the introduction of the first generation alpha 7x’s, and another with the a7RII. Then came the a9, which was even better. The a7RIII UI is pretty close to the a9, but missing the shutter mode and focusing mode controls on the left part of the top deck. The dials aren’t so flimsy-feeling. But, compared to the D850, with its UI that Nikon has incrementally evolved for more than a decade, the a7RIII is still well back in second place in this two-camera race. Although there is room for one on the left side of the top deck, Sony still has no reflective status panel, which means that you have to go to the menus a lot. With the Nikon, you hardly ever do. By the way, my favorite such panel is the one on the GFX, but the Nikon’s LCD one is perfectly serviceable. There is one feature that mirrorless cameras have that DSLRs don’t that makes the lack of a top status panel tolerable, and that’s the fact that you can navigate the menus structure using the EVF when the ambient lighting washes out the LCD back panel.
One thing I don’t like about either camera is the way that the lockable controls work. You have to hold down a button and twist a dial at the same time, and sometimes that’s an awkward and slow move. As an example of how I think this should work, I give you the GFX, in which you press a button which locks the dial if it was unlocked, and vice versa, and the dial stays either locked or unlocked until you press the button again. I use the exposure compensation control a lot, and I do like the fact that it’s right on top of the a7RIII, where you can see and adjust it without even turning the camera on. It’s pretty easy to adjust the equivalent function on the D850 though.
While Sony is clearly behind in some parts of the UI – I’ll get to some of the areas where they are ahead further down the page – they are moving fast in the right direction, and they are moving faster than Nikon, which is just doing minor tweaks to its already-refined UI.
Another aspect of ergonomics is the tactile experience of using the camera. Even though it has grown to a9-ish size, I find the a7RIII a little small in my hands. I use it with the Really Right Stuff (RRS) base plate (but not the companion piece that makes it into an L-bracket), and find the additional height useful. The new generation of RRS plates have a place to stow the Allen wrench. It’s a nice thought, and I didn’t have any trouble with it using the a7RIII on a tripod is slow-moving situations. But when hand holding the camera I found that the Allen wrench kept me from being able to quickly tilt the LCD panel away from the body, and I consigned the wrench to a drawer.
Two more shots from that series at 1:1:
The D850 is more comfortable for me to hold, but with large lenses, I prefer the D5. I think the D850 will be just fine with the grip, but I don’t know that for a fact since the grips seem to be virtually unobtainable.
I didn’t mind the weight of the D850 and the 105/1.4 when I was shooting, but the increased weight of my Nikon gear over the Sony stuff I have gives the a7RIII an advantage when I’m planning what to carry in my camera vest or on a trip.
The mechanical shutter and the flapping mirror on the D850 combine to make a lot more noise than the EFCS-mode shutter on the a7RIII. Handheld EFCS is not practical – or particularly beneficial – on the D850. The D850 shutter seems louder than the D810 one. The difference in sound between the Sony and Nikon cameras was enough to distract people. Both cameras have an electronic shutter, and both scan full-frame single shot images at about 1/15 second. The a7RIII offers a scan speed of twice that in continuous compressed mode. I didn’t use the electronic shutter on either camera for any of these pictures. I could have done so with the a7RIII, but I don’t think there is any point to using the D850 electronic shutter handheld, at least for my kind of photography, since to use ES requires that you use live view, and there is no way to do that handheld except by holding the camera out like an iPhone. If I’d been using the a9 for these shots, I’d have used the electronic shutter almost all the time.
The a7RIII is faster than its predecessor, and it’s fairly fast in an absolute sense. The D850 is much faster. You can turn it on as you’re raising the camera to your eye and it’s ready when you are. The Sony needs a couple of seconds to get its act in order. When you format a card with the D850, it’s over in an instant. The Sony can take 5 or 6 seconds for a 128 GB 100 MB/s card, which can seem like an eternity when you’re changing cards and things are happening around you (some of the earlier a7x cameras could take more than a minute to format those big cards). Fortunately, with either camera, you hardly ever have to change cards.
Autofocus use experience
This is one of the most critical issues for the kind of photography I was doing, and one of the most complicated to describe.
First, both cameras have a bewildering number of autofocus options, and I didn’t even try to explore them all. Instead, I set the cameras up similarly, using AF-C and allowing face detection, and giving the cameras a wide choice of what to focus on. I programmed the AEL button on the a7RIII for eye-autofocus; there is no similar capability on the Nikon. In order to concentrate on the differences in more automated autofocus systems of the two cameras, I chose not to use the spot-autofocus features, even though there were many times when they would have been preferable. The a7RIII has a new joystick to control the spot position, which is a huge improvement over the two-step mess of the a7RII, but I think the D850 haptics are better.
When you give the camera a good deal of freedom in picking the focus point, it’s important to know just what it’s doing, and in this realm, the Sony is a clear winner. It shows you groups of green squares when it is focusing on something other than a face, big green rectangles to show you the faces it’s favoring, and a tiny green square to show you which eye you’re focused on win eye-AF. The Nikon is nowhere near as communicative; it shows you a gray square where it’s currently focused and call that it. By the way, I like the red squares the D5 uses better; they’re easier to see.
Once you’ve decided what the camera is focusing on, you can then decide if that’s what you want it to focus on. Usually, it is, and all you have to do is trip the shutter. If it’s not, and you want it to focus on a face, with both cameras the trick is to move your chosen target nearer the center of the frame, try again, and reframe your subject while slowly moving it where you want it. The Nikon will follow it quite well until you get near the edge or unless it is distracted by another face that got moved to the center. The Sony plays the same game, but not quite as well. But the Sony has a trick up its sleeve: eye-AF. Invoke that, and it will track the eye that it picked quite well.
In practice, the Sony system is easier and faster to use. The better visual feedback is the thing that makes the difference.
The D850 uses phase-detection autofocus (PDAF) all the time you’re not in live view, and I didn’t use live view at all for these pictures. PDAF is fast, but it’s not very repeatable, and can suffer from systematic errors that vary with f-stop and subject distance, and are thus hard to calibrate out (with the 105/1.4, I used corrections derived from earlier testing). For active subjects with constant velocity, the D850 uses a prediction algorithm that is quite effective.
The a7RIII uses a combination of PDAF and contrast-detection autofocus (CDAF). It uses PDAF at first, because it’s faster, then trims up the focusing with CDAF. There is no calibration required (or possible, with native lenses). The Sony does not use predictive autofocusing but relies on tweaking speed and the fact that the AF sensors are not blacked out by the swinging mirror.
The D850 AF is better for violently moving subjects such as you encounter in sports photography. For the kind of work I was doing here, the Sony system is far better. The reason is the keeper ratio.
It’s not that the D850 AF is inconsistent by DSLR standards. It is very good and isn’t far behind the D5, which has arguably the best DSLR AF systems in the world. It’s that the a7RIII CDAF tweaking takes accuracy to a whole new level. When you take a series of shots with the D850, you have to go through them and pick the sharpest ones. With the a7RIII, most of the time (assuming the camera is focusing where you want it to focus), they are all sharp. This makes editing much faster and more stress-free. Instead of constantly zooming in and out to check focus, you pick the best shots from low-magnification displays, check them briefly, and toss the rest. And you’re hardly ever choosing between two slightly out of focus shots like with the D850. When I say slightly out of focus, I’m talking about distinctions that most DSLR shooters aren’t used to making, but using the a7RIII (and the II) raises the bar for what’s in focus, and it’s hard to go back.
Autofocus and finder modes
All the autofocus modes of the a7RIII are available when using the electronic viewfinder (EVF) or the liquid crystal rear display (LCD). They work the same way, and they display the same amount of information. PDAF is only available on the D850 when you’re using the optical viewfinder (OVF). When you want to use live view, you drop back to slow and inflexible, but quite accurate, CDAF. For the kind of shooting I was doing here, this makes the D850’s live view useless. It is very convenient with the a7RIII to be able to move the camera away from you and flip up the LCD when the EVF proves awkward. For the kind of work I was doing, that option is effectively foreclosed by the D850.
Autofocus in difficult light
Both cameras do about the same in dim light. The Sony eye-AF does not work well with strong backlighting. The eye-AF in the D850 does not work in any circumstances. ;<)
The a7RIII has in-body image stabilization (IBIS). I turned it on for all the shots in this series. However, I didn’t miss it much in the D850, since almost all the time I was sufficiently concerned with subject motion that I picked fairly fast shutter speeds.
Continuous shooting speed
Without the (so far unobtainable) grip, the maximum continuous frame rate on the D850 is 7 fps. The a7RIII can shoot at 10 fps. The difference is noticeable, and welcome sometimes. At full cry, the D850 is pretty noisy.
From a practical point of view, getting to 10 fps with the Sony requires that you use compressed raw, and it drops the digitizing precision to 12 bits, but at the ISO settings and subjects I was using for this set of images, neither of these affects image quality. When you do that, you’ve got about an 80-shot buffer. I never managed to fill it. Using 14-bit lossless compression, the D850 is supposed to have a 50-shot buffer. I did fill the D850 buffer on two occasions. I don’t think I took that many pictures, but maybe it was that I was using 150 MB/s SD cards in both cameras, or maybe the buffer wasn’t empty when I started paying attention. You could argue that to make the playing field level, I should have used 12-bit lossy compression for the D850, which would have made it the winner for buffer capacity.
Both cameras employ Aptina DR-Pix technology, and both switch to the high-conversion-gain mode 2 2/3 stops above base ISO, so that the conversion gain ratio of the two modes is the same with each camera. The a7RIII has very slightly less noise at ISO settings around 1000, but the difference is insignificant for pictures like these.
Comparing the a7RII and the D810 battery life resulted in a big win for the Nikon. Not anymore. With the new cameras, I call it a tie. The a7RIII uses the a9 battery, while the capacity of the battery that ships with the D850 is only marginally higher than the D810 battery (you can use either Nikon battery in either Nikon camera).
At the end of the shoot, what matters most is how many god images you got, and in that respect, this match ended in a tie. Here’s the breakdown of the lenses used in the images that I thought worth keeping from the first few days, when I was using only the 85 on the a7RIII and the 105 on the D850.
I admit to liking the “look” of the 105/1.4 wide open more than the Batis 85/1.8, so some of this has nothing to do with the bodies.
Voting with my bag
At the end of the family gathering, we all went to Santa Cruz for 3 days. I picked a Tamrac rolling bag to carry all my camera stuff. The question was, what should I put in it? I considered packing both the D850 and the a7RIII and continuing to carry on my comparison. But when I considered what that would mean, the weight got to be too much, and I had to choose one camera system or the other. That wasn’t a hard decision. I took the a7RIII, the 12-24/4, 35/2.8, 55/1.8, and 85/1.8 lenses, and an a9 with the 100-400 (I never used either the a9 or the long zoom). The key factors were weight and the greater focus accuracy of the Sony system.
Netting it out
The D5 and its D-single-digit predecessors have always been my go-to event cameras. The D850 can do most of what the D5 can, and some stuff the D5 never thought about doing. But for available-light, no-modifier event shooting, I think there’s a new sheriff in town: the a7RIII with an a9 backup. When the action is so fast that you’ve got to turn the camera loose to pick the focus point with no fiddling, the D5 is the winner, and the D850 is close to that. But if you’ve got the tiniest bit of time, you can do the job better with the a7RIII, and your keeper rate for print and prints will be much higher (the D5/D850 PDAF is accurate enough that your keeper ratio for low-res web shots will be about the same.
When I plan to use a lot of lenses at an event, I put them in a Domke (or, if I’m feeling the need to be a little dressier, a Billingham) photo vest. Carrying E-mount lenses that way is a lot easier than if I use F-mount ones, at least with the F-mount lenses I use. Admittedly, I tend to pick smaller and slower lenses for the a7x cameras than I do for the Nikons.
In case it’s not obvious, I think these are both great cameras.