It’s not you, it’s me…
If you’re a photographer thinking about switching to mirrorless, I just thought it might be useful to read about someone else’s experience doing the same thing. I used to have an extensive collection of Nikon camera bodies, lenses and accessories, including a D850. However, I switched to the Sony mirrorless system last year, and I now have two Sony a1 cameras and various lenses from 12-24mm all the way up to 600mm—plus 1.4x and 2.0x teleconverters.
So what happened, I hear you ask? Was it a good idea? Are you happy with your decision? Any regrets? Here are my answers to all those questions…
Back Story
This all came about because I was due to go to Arviat in Canada to photograph the polar bear migration last November, and I wanted to get a new camera before flying out there. I’d read a lot online about the benefits of mirrorless cameras, and I was keen to do something different to get myself out of what I thought of as a bit of a rut.
After watching dozens of video reviews, I decided that the best option was the Sony a1—or A1, alpha 1, Alpha 1, ⍺1 or however you want to write it! It seemed to offer the best of both worlds: a high-resolution, full-frame sensor, a high frame rate, a deep buffer and the best autofocus system on the market, including human, animal and bird eye detection and tracking.
The only problem was that I had a lot of very expensive Nikon lenses, and I couldn’t use any of them without an adaptor. That would’ve affected image quality and autofocus performance, and I also wouldn’t be able to benefit from the smaller, lighter, native mirrorless lenses.
The mirrorless Canon R3 and R5 were available, but that wouldn’t have solved my problem as the mounts would still have been incompatible. That left the mirrorless Nikon Z9, but unfortunately it hadn’t come out by the time I left for Canada…!
In the end, I decided to bite the bullet and bought one Sony a1 camera body, a 400mm lens and a 1.4x teleconverter. I used them almost exclusively on my trip to Canada and then again when I spent a week in Antarctica. In fact, I was so happy with my new camera that I traded in all my Nikon kit and bought another a1 and all the lenses I might possibly need. I lost about a third of the value of my Nikon kit—mostly because my D850 was a write-off after getting splashed by a wave in the Southern Ocean! However, I managed to get a bank loan to make up the difference, and I now have the following Sony gear:
Cameras
2 x Sony a1 mirrorless cameras
Lenses
Sony FE 70-200 mm f/2.8 G Master OSS II lens
Sony FE 400 mm f/2.8 G Master lens
Sony FE 600 mm f/4 G Master lens
Why Switch?
There are many reasons to switch from a Nikon D850 to a Sony a1, and you can see a detailed, line-by-line comparison here. In my case, I wanted a higher frame rate and better autofocus. To understand my decision a bit better, let’s take a look at each of the cameras in turn.
Nikon D850
Sensor: 46MP full-frame BSI-CMOS sensor
Raw frame rate: 7 fps (9 fps with the MB-D18 battery grip)
ISO 64 - 25600 (expands to 32-102400)
Eye tracking: No
Video: 4K (UHD) - 3840 x 2160 pixels
Battery life: 1,840 shots
Weight: 1 kg (2.2 lbs)
DxO scores: 100 overall, 26.4 colour depth, 14.8 dynamic range and 2660 low light ISO
Pros
Good autofocus (for a DSLR!)
4K video
Touchscreen LCD
Decent resolution
Cons
Low frame rate
Few customisation options
LCD screen not fully articulated
Poor video autofocus in live view
He-Lion, taken with my old Nikon D850 and 800mm f/5.6 lens
The Nikon D850 was probably the best DSLR on the market when I bought it in December 2017, and it’s probably still the best DSLR on the market even now! It offers good resolution, a vast ISO range, 4K video and a decent autofocus system, especially in AF-C 3D mode for tracking wildlife. However, it’s let down by the poor frame rate and the inevitable limits placed on the autofocus area by the DSLR format.
Body and Handling
The D850 feels good in the hand. It’s solid, durable and ‘chunky’ in a good way. The button layout is well designed, and I appreciated little touches like the depth of field preview button and the electronic level. However, there are very few customisation options, and that becomes a problem when there are so many manual switches and buttons that can’t just be ‘reset’ electronically. Many’s the time that I’ve accidentally ended up on the wrong autofocus, white balance or exposure setting just because I didn’t take the time to check my settings before a game drive.
The optical viewfinder is obviously one of the key distinguishing factors between DSLRs and mirrorless cameras. It offers the most realistic view of the world in front of you, and it’s especially useful in low light. However, the downside of the DSLR design is the lack of blackout-free shooting. At the end of the day, light can pass through to the viewfinder or the sensor, but it can’t do both! That’s why the mirror needs to flip out of the way while taking a picture, which causes a temporary ‘blackout’. It doesn’t matter much at high shutter speeds like 1/1000 of a second, but if you like slow pans as much as I do, it becomes a real problem…
The alternative to using the viewfinder is the touchscreen, of course, but live view doesn’t really help when you’re a wildlife photographer! Having said that, the addition of touchscreen functionality makes the D850 a bit easier to use than the old D810, and the menu system is pretty logical and easy to navigate once you get used to it.
Another feature that elevates it above its Canon DSLR rivals is the way it ‘remembers’ the maximum aperture with variable-aperture lenses. If you set it to f/3.5, say, when you’re zoomed out, but the lens forces it down to f/5.6 when zoomed in, the D850 will automatically revert to f/3.5 when you zoom out again. Neat!
However, it is pretty heavy—especially if you add the MB-D18 battery pack, which weighs another half a kilo (1.055 lbs)!
The other problem is the build quality. Yes, the D850 is supposed to be durable and weather-sealed, but I had a succession of problems with it. Firstly, the screws on the lens mount came loose on my four-month trip to Africa in 2019. I didn’t know what was going on, but I suddenly couldn’t focus using my 800mm lens. That was very frustrating, and it was only much later that I realised the problem. In the end, I had to send both camera and lens back to the manufacturer for repair, and it cost my insurers over two grand to fix!
Second, it stopped working completely when I was on my Antarctic trip. One day, I was on a Zodiac excursion, and I had my D850 and a1 clipped to my SpiderPro belt. They were both in rainproof covers, but that didn’t help much when a rogue wave splashed over the side of the rib and engulfed my D850. It stopped working immediately, and even taking the battery out for a whole minute didn’t fix the problem. In the end, I got it working again the next morning after it had warmed up and dried out overnight, but I couldn’t set the shutter speed or aperture. When I got back home, I gave it to London Camera Exchange to look at, but they told me it was a write-off!
Optics
The D850’s sensor is not stacked, but it offers good resolution, and the low native ISO is an advantage if you want the ultimate in noise-free images. It also scores higher than the a1 on the DxO scorecard, both overall and for colour depth and dynamic range.
However, I always thought my images were softer than they should’ve been. I have a thing about sharpness. I’m a bit obsessed with it, and the eyes of my subject just HAVE to be sharp! The D850 should have offered plenty of resolution, but I was always a bit disappointed and frustrated by how soft the images were.
Some of that was due to the lenses I was using. My 800mm lens was excellent, and I used it for around two-thirds of my shots. However, my 80-400mm lens just didn’t perform. That was perhaps a function of how old it was and how much of a battering it took in the back seat of various safari trucks, but still…!
The sharpness problem first came to my notice when I went to Svalbard in June 2014. I remember one day in particular. We saw a mother polar bear with her two cubs, and they put on a great show for us for more than an hour. I shot hundreds of images from a tripod in the bows with the rest of the guests, and I was excited to have a look at them all on my laptop.
However, when I looked at them at 100%, none of them was sharp enough. I was devastated! To have such a great sighting and invest so much time and effort in taking pictures without getting any decent results was a massive disappointment. One of the guests later advised me to fine-tune the autofocus of my lens and camera, but it was far too late by then…
Admittedly, I was ‘only’ using a Sigma lens, and after that I switched to Nikon glass all the way, but the seeds of doubt were sown, and they grew and grew over time…
Autofocus
Lack of sharpness isn’t just down to the sensor and the optics. It’s also related to the autofocus system. Now, the D850 does have a good one on paper, and the AF-C 3D setting did provide decent results—for a DSLR! Having now used a mirrorless camera for a year or more, I realise its limitations.
The first and most obvious one is that the autofocus area is limited to the central zone. If you want to place your subject outside that area, then you have to focus and recompose. That might work well in theory, but it presents too many chances for things to go wrong.
Mirrorless cameras obviously don’t have that problem, and one more thing you get from a mirrorless camera is eye detection. That’s simply not possible with the optical viewfinder you get with a DSLR. Perhaps it’s an unfair comparison, but it is what it is. You can’t just excuse the D850 by saying, “Well, it comes with the territory.”
Again, that was one of the main issues behind my switch to mirrorless. I asked myself among other things, which autofocus system do I want to be using the next time I see a cheetah kill? The answer was pretty obvious.
The first time I went to Kicheche Bush Camp with Paul Goldstein, I saw FIVE cheetah kills, but I only managed to get ONE decent shot with my D850! That’s just not good enough.
I haven’t yet had a chance to go back there with my Sony a1s, but I’m planning a trip next year, so watch this space…!
Features
The main problem with the D850—as with most Nikon DSLRs—is the frame rate. Seven frames per second is just not good enough for wildlife or sports photography, and even adding the battery grip only raises it to 9 fps. I know there’s a trade-off between resolution and frame rate, but Nikon just doesn’t seem to have been able to find the right answer to the problem.
Having said that, the D850 does have a wealth of features that you might expect from a pro-level DSLR:
4K video
8K timelapse mode
Wireless, Bluetooth and NFC connections
Tilting 3.2”, 2.359k-dot touchscreen
External flash shoe
Optical viewfinder
Raw support
Face detection
Mic and headphone ports
Weather sealing
AE bracketing
Focus bracketing
Focus stacking
Illuminated buttons
Flash sync port
200,000-cycle shutter life expectancy
2 x storage slots (1 x XQD/CFexpress B and 1 x SDXC/SDHC/SD UHS II)
Smartphone remote control
EV -4 minimum focus sensitivity
Anti-flicker mode (for indoor shooting in fluorescent light)
Given all these bells and whistles, you have to wonder why the D850 wasn’t given faster continuous shooting. Maybe the Nikon engineers just couldn’t work out how to do it, or maybe they deliberately chose to add other features at the expense of the frame rate. I honestly don’t know, but it was a key reason why I left the Nikon universe…
Sony a1
Sensor: 50MP full-frame BSI-CMOS sensor
Raw frame rate: 30 fps (lossy compressed)
ISO 100 - 32000 (expands to 50-102400)
Eye tracking: Yes (human, animal and bird)
Video: 8K 7680 x 4320 pixels
Battery life: 530 shots
Weight: 0.7 kg (1 lb 10 oz)
DxO scores: 98 overall, 25.9 colour depth, 14.5 dynamic range and 3163 low light ISO
Pros
Best autofocus on the planet
Highest available Raw frame rate
Largest sensor in a DSLR (apart from the A7R series and medium format cameras)
Highly customisable, with three presets on the main dial
Cons
Can’t identify subject as human, animal or bird (yet!)
Small grip not ideal for large hands and may leave blisters
No oversampled 4K video
Very expensive!
Eye of the Rhino, taken with my Sony a1, a 600mm lens and a 1.4x teleconverter
The Sony a1 is probably the best mirrorless camera on the market—both for wildlife photography and anything else, really. It ticks all the boxes for resolution, frame rate, buffer size and autofocus capability, and the word ‘trade-off’ doesn’t seem to be in Sony’s vocabulary!
Body and Handling
Mirrorless cameras and lenses tend to be smaller and lighter, and the a1 is no exception, weighing in at 278g less than the D850. My 400mm and 600mm lenses are also light enough for me to shoot handheld, which is a nice change after using the impossibly heavy Nikon 800mm lens for so long!
The Sony a1 doesn’t have a built-in vertical grip, but I like the flexibility of being able to fit mine as an optional extra. Holding a 600mm lens is a bit tough for long periods, so I’ll take any weight advantage I can get! The only downside of not fitting the battery grip is that the a1 is a bit too small for my hands, and when I spent three weeks in Botswana recently, I did end up getting blisters on several fingers.
The other big advantage of the a1 is the opportunity for customisation. There are five named custom buttons (C1-5), but there are actually 13 buttons in total that you can customise, with different settings possible for stills, video or playback. This is great for one-touch access to functions such as focus area, white balance, eye detection and silent shooting, and I use all mine on a regular basis.
The other custom options are the exposure presets on the main dial. They are absolutely crucial to the speed of my workflow. When I get a wildlife sighting on a game drive, it might only last for a few seconds, so the ability to switch seamlessly from portrait to action or slow pan mode by turning one dial is a godsend.
Admittedly, the main dial does need to be unlocked by pressing the button on top, which makes it harder than it should be when you have your eye to the viewfinder. However, the ability to save almost every single setting in those presets is a real time-saver.
The electronic viewfinder on a mirrorless camera has historically been a drawback, with viewfinder lag and blackouts a real problem. However, Sony has managed to solve those problems convincingly with the a1’s unbelievably bright and clear 0.9x 9437k-dot EVF. You get blackout-free shooting with no noticeable lag at all.
The first time I used it, I was a bit disappointed that the view looked a bit ‘digital’, but that’s only because I thought I was still using an optical viewfinder! Unless you zoom in all the way, it’s almost impossible to tell them apart. The added advantage of the EVF is that you get a WYSIWYG view of what your shot will actually look like, which makes it much easier to use exposure compensation, for instance. You also get features like focus assist and zebra stripes that simply aren’t possible on a DSLR.
Finally, there’s one small problem I’ve found with the naming and playback of files. I can set one storage slot to ‘overflow’, but I can’t number or play back the images sequentially from both slots. The numbering only goes up to 1,000 even though there are five digits available for the sequence number, which should be enough for 99,999 images. If I try to import the files to my MacBook Pro using Image Capture, I constantly get warnings about duplicate filenames. It’s easier if I use Lightroom, but then I end up with lots of filenames ending in ‘ 2’ or ‘ 3’!
The problem extends to image playback, and it sometimes seems as if images have simply ‘disappeared’ simply because they’re on the other memory card. This is ludicrous, and any Sony engineer who’d actually used the a1 for any length of time should’ve spotted the issue and sorted it out. However, it’s still there, and all I can do is wait for the next firmware update…!
Optics
Even now, I’m still amazed by the sharpness of the images I get with the a1. Admittedly, I did get a few soft results early on, but I quickly learned that was down to using a teleconverter. Yes, the 2.0x TC conveniently turns my 70-200mm lens into the 140-400mm equivalent of my old 80-400mm Nikon workhorse. However, it comes at the price of two stops of light, and the autofocus becomes much slower and less reliable. I learned my lesson after my Botswana trip in May. When I went back in October I hardly ever used a teleconverter, and I was very happy with the results.
My only slight complaint now is that the background in my images looks a little bit ‘odd’. It’s almost as if I’m getting digital artifacts from oversharpening. It doesn’t happen very often, and I can always fix it in post by reducing the texture slider in Lightroom, but it’s a bit annoying. Otherwise, the images are as sharp as I could possibly want, and the combination of putting my 400mm lens on one camera and my 600mm lens on the other works very well.
Video
The D850 offers UHD 4K at 30, 25 and 24p, and you can choose to use the full sensor width (FX) or from a DX cropped region. You can save footage in either MOV or MP4 formats. The 4K modes are shot in h.264 at 144Mbps, which involves 4:2:0 chroma subsampling. This is inferior to the 4:2:2 alternative, but that generally needs an external recorder or a more advanced, specialist video camera.
You can also drop down to 1080p footage at up to 60 fps—again using either the full width of the sensor or the DX cropped region. One of the advantages is electronic stabilisation, which works very well in both modes—at the expense of a 1.1x crop. The 1080p footage is shot in H.264 at various bitrates:
60 and 50p can be shot at 48 or 24Mbps
30, 25 and 24p can be shot at 24 or 12Mbps
Slow motion footage can also be shot at 120 or 100 fps using the DX region of the sensor. The output is either 1/4th speed 30/25p or 1/5th speed 24p.
In terms of quality, the full-width footage suffers from line-skipping and moiré effects. The DX footage looks better, with symmetrical aliasing that suggests pixel binning. The subsampling reduces low-light performance as the full width of the sensor is not being used. It’s a similar story if you switch to 1080p.
Autofocus
Sony has been making full-frame mirrorless cameras for longer than anyone else, and it shows when it comes to their autofocus systems. The a1 offers human, animal and bird eye detection and tracking in different focus areas, and it really works!
This is a real boon to any portrait, wildlife or sports photographer because getting the eye sharp is so important. The a1’s autofocus comes with tracking as well as eye detection, but it’s ‘smart’ enough to know that the eye takes priority, so it will follow the eye and keep it in focus even if it leaves the selected focus area.
Focus areas are the mirrorless equivalent of focus points. You simply choose the area you want the camera to search for an eye (or another subject) and then let the autofocus system do its job. If you have an open field of view, then Wide (or full-frame) mode works fine, but you may need to switch to Zone or Expanded Spot if there are too many leaves or branches in the way.
The advantage of Expanded Spot is that the camera uses the focus points around the central one just in case it misses focus for a moment. That means you’re less likely to get a soft image in amongst all the sharp ones.
In practice, I’ve found I use Zone and Expanded Spot the most, so I’ve now limited the available focus areas to those two. There’s a tracking option available for each focus area, but that would slow my frame rate down to 20 fps, so I simply activate focus and tracking by pressing the AF-ON button. I’ve checked the results, and I can still get 30 fps.
Customisation plays a key role here. I’m constantly switching between focus areas and eye detection modes, so I’ve set up two custom buttons near the shutter release that I can use to toggle between all the different options. That’s obviously way more convenient than having to search through the menus, and it saves me a lot of time.
The only problem I currently have with the autofocus is that I have to select the type of subject manually. That’s a bit of a pain, and it’s especially frustrating because there’s no icon in the EVF to tell me whether I’m in Human, Animal or Bird mode.
The good news is that the new Sony a7R V lets you tell the camera to work it out for itself, so I look forward to Sony retrofitting that feature on the a1 in a future firmware update!
Video
I generally shoot video on my iPhone 12 Pro Max, which is capable of 4K footage. I’ve only used my Sony a1 once. I was in Kenya filming a leopard yawning, but when I downloaded all my images on to my laptop after my game drive, the clip had disappeared! It turned out that the a1 puts video files and image files in different places on the memory card. Very annoying…
Anyway, the a1 does offer 8K video in various formats, including XAVC S, XAVC HS, H.264 and H.265. However, 8K resolution is too high to display properly on just about any monitor these days, so it’s a bit pointless using it. If you drop down to 4K, though, the a1’s footage isn’t oversampled. That means that it’s a lot less sharp and detailed than what’s available on the Z9 (or R5).
However, the a1 does have gyroscopic stabilization (unlike the D850), and there’s no recording limit. You also get convenient headphone and microphone ports.
Features
The a1 comes with just about all the features of the D850 plus a few more of its own. However, it’s worth looking at the small print. I mentioned before that Sony doesn’t seem to know the word ‘trade-off’, but trade-offs are there if you look hard enough:
The maximum Raw frame rate of 30 fps can only be achieved using a supported lens in lossy compressed format, and there are a few other conditions.
The resolution of the EVF falls from 2048 x 1536 to 1600 x 1200 if you choose the highest refresh rate of 240 fps.
4K/120p video comes with a slight crop.
Pixel Shift High-Res Mode for 199MP images doesn’t work with AF-C and requires desktop software to combine the images.
Having said all that, the a1 still offers a tremendous list of features. These are the ones it shares with the D850:
Wireless and Bluetooth connections
Tilting 3.2” LCD touchscreen
External flash shoe
Raw support
Face detection
Mic and headphone ports
Weather sealing
AE bracketing
Flash sync port
2 x storage slots that accept UHS-II SD cards
Smartphone remote control
EV -4 minimum focus sensitivity
Anti-flicker mode (for indoor shooting in fluorescent light)
These are the specifications that beat those of the D850:
Frame rate (30 fps vs 7 fps)
Viewfinder magnification (0.9x vs 0.75x)
Sensor resolution (50MP vs 46MP)
Maximum ISO (32000 vs 25600)
Focus points (759 vs 153)
Weight (737g vs 1015g)
Low light ISO (3163 vs 2660)
Maximum video resolution (7680 x 4320 vs 3840 x 2160)
Shutter life expectancy (500k vs 200k cycles)
…And these are the features the D850 doesn’t offer at all:
Gyroscopic stabilization
In-Built Image Stabilization (IBIS)
Stacked sensor
Blackout-free shooting
Unlimited video recording
Anti-dust shutter mechanism
Full-size HDMI port
Pixel Shift High-Res Mode
Human, animal and bird eye detection
Eye tracking
Webcam functionality
Verdict
I guess you know what’s coming, right?! Yes, I’m very happy with my new Sony a1 cameras, and I’d never go back to the D850. That doesn’t mean, of course, that you can’t take good pictures with it (or with any DSLR), but mirrorless cameras are the future. They offer so much more than DSLRs that I very much hope you invest in one soon (if you haven’t already).
The top mirrorless cameras at the moment are the Sony a1 (obvs!), the Nikon Z9 and the Canon R3 and R5—depending on whether you think resolution or frame rate is more important. I recommend them all, but the a1 just comes out on top due to its combination of resolution, frame rate, buffer size and autofocus system.
What do you get the photographer who has everything? A Sony a1…!
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