Sony A7 III Video
Sony A7 III Video Features, Specs & Analysis
by Jaron Schneider
Posted May 22, 2018
4K Video Framegrab (click for full-res)
The Sony A7 III is no doubt enticing to video shooters because of its price point: at just $2000 it shoots 4K video in a full frame format, should have good ISO performance, and comes with S-Log included. It is considerably cheaper than a number of other full frame camera on the market, and comes with better specifications (say, compared to the Canon 6D II or 5D Mark IV). A more likely comparable product would be the Panasonic GH5, since they share the same price point and similar features. The A7 III is perhaps even more appealing when you consider the smaller GH5 sensor, and the fact that V-Log in the GH5 is an paid, after-purchase add-on. So knowing where the A7 III sits in prospective buyers' minds, let's take a look at what it actually can do when it comes to video and what the shooting experience is like.
Sony A7 III 4K Video Review
4K, Full HD and Frame Rate Options
In NTSC, the Sony A7 III offers two different 4K frame rates at two different bitrates: 30p and 24p, at 100 MBPS and 60 MBPS. For the same length of shooting, you can expect to save a little bit less than half the total storage space between the two and in most cases you won't likely notice any dip in quality.
Here is the full breakdown of 4K shooting options:
- 23.98/25/29.97 fps (100 Mb/s XAVC S via H.264)
- 23.98/25/29.97 fps (60 Mb/s XAVC S via H.264)
If you look very closely at 100%, you will see a slight difference in how sharp/vibrant shapes are. In my side by side video comparison, I would probably not have noticed a difference had I not known there was supposed to be one.
And... that's all when it comes to 4K frame rate options on the A7 III. It doesn't have the option to select between UHD and Cinema 4K, and it doesn't offer 4Kp60 either. When compared to other full frame offerings, this is generally par for the course with the exception of the Canon 1DX Mark II, which doesn't offer full frame readout like the Sony does. At this point, video shooters will have to decide what is more important: full sensor readout without pixel binning or line skipping, or slow motion in 4K with a crop.
Interjecting personal opinion here, I think I prefer having more frame rate options over the higher quality video promised by the A7 III. Why? Mostly because that higher quality isn't much different to the naked eye, and creatively-speaking, I'm going to get more out of frame rate options than I will out of that quality boost.
However, price is a major player here. To get that lower quality 4K/60p in the 1DX II, I have to shell out more than double the price of the A7 III. That's not honestly a fair comparison, so let's look at the Panasonic GH5 instead, since it's asking price is identical to the Sony.
4K Video Framegrab (click for full-res)
On the GH5, we don't get a full frame sensor, but we do get a great many more options in 4K. Not only do we get the high bitrate that the Sony offers, we also get it in a choice among 8 bit (which is the only option on the A7 III), 10 bit, as well as multiple compression options for either two bitrates, All-I or Long GOP. We get those three choices in both UHD and Cinema 4K as well. Oh, and we also get 4Kp60 in 8-bit.
Now, does every filmmaker need the laundry list of options the GH5 offers? No. For most, what you find on the A7 III will suffice, though 60p would certainly have been a really nice addition. In the end, that's my only gripe in terms of the A7 III's 4K offerings. It was expected however, since none of the Alpha cameras have, to date, been able to handle 4Kp60. If it wasn't in the A7R III, I personally didn't expect it in the A7 III.
In full HD 1080p, the Sony has several more options. Though it doesn't give you multiple bitrate options for 24p, it does give you two for both 60p, 30p, and 120p (and in their PAL equivalents):
- 100/120 fps (100 Mb/s XAVC S via H.264)
- 100/120 fps (60 Mb/s XAVC S via H.264)
- 23.98/25/29.97/50/59.94 fps (50 Mb/s XAVC S via H.264)
- 50/59.94 fps (25 Mb/s XAVC S via H.264)
- 25/29.97 fps (16 Mb/s XAVC S via H.264)
- 50/59.94 fps (24 Mb/s AVCHD via H.264)
- 50/59.94 fps (17 Mb/s AVCHD via H.264)
This is a nice, healthy list of options that covers the bases for anyone shooting in 1080p, which is a lot of people still. What's more, you get the excellent 5x slow motion in the 120p, which can look really spectacular.
Sony A7 III 1080p Video Review
Unfortunately, the drop in quality of the 1080p footage compared to the 4K footage is noticeable. Footage is less clear, the details aren't as crisp, colors are more muddled, and it's overall lesser than what the 4K is capable. This was a problem that plagues a lot of modern cameras in the SLR-style bodies. The 1DX II, the 5D Mark IV, and even the GH4 had this same problem. At least on the A7 III, it's not a huge dip in quality, and the 120p footage once slowed, looks pretty good. If you plan to only shoot in 1080, you will probably find the A7 III to be one of the better options for the job in this form factor and price point.
ISO is, for almost all video shooters these days, a huge player in the decision-making process. It's why the GH5S is such an intriguing option. So how does the A7 III do? Really, really well actually. Though I wouldn't say all clips past ISO 6400 are "sharp" or "crisp," footage at just about every ISO is going to be considered usable by a wide range of shooters. Even at max video ISO of 102,400, the A7 III looks... pretty darn good. Sure, there is visible noise and the edges of objects in frame are not as distinct as they were at, say, ISO 6400, but they're absolutely still usable clips.
For example, in a wedding scenario, a couple is going to find that capturing any footage at all in near darkness to be a win, and the A7 III footage absolutely does that. It's not the best out there, but it's also by no means the worst. I would say that the best quality footage will be captured up to ISO 6400, but you shouldn't feel tethered to that ISO as your maximum.
Sony really was the first company to impress me with in-body image stabilization, but the technology hasn't really advanced much in my opinion. At least, it doesn't come across to me in a video shooting situation that the in-body image stabilization (IBIS) is market-leading anymore. It's by no means bad, and I'm glad it is included when faced with the alternative of not having it at all.
But compared to the GH5, the A7 III is significantly less good at stabilizing normal human walking gait. Panasonic's stabilization absorbs footfalls far better when compared side by side with the A7 III, and I've found that the Sony sensor will also succumb to "wobbling" when hit with something like extreme wind (the Panasonic can also have this problem).
That said you can turn off the IBIS if you don't want it. This is hugely advantageous for some locked-off camera situations where you don't want to see the sensor attempting to compensate for vibrations that would result in "liquid-like" sensor movement in the corners. The IBIS cannot be fully turned off (the "off" setting still means the camera is actively trying to hold the sensor still; the sensor is not physically locked in-place). More advanced videographers might still experience unexpected issues with IBIS, which is why Panasonic left it off their GH5S. So while the Sony isn't the best IBIS money can buy, it's more versatile than what in my opinion is the market-leading Panasonic GH5.
4K Video Framegrab (click for full-res)
If you're going to point to one thing about the A7 III that is less than ideal, it's the overall experience shooting with the camera: it can often be quite the pain to use. My experience is pretty heavily colored by my time with both Canon and Panasonic cameras, but the way the user must interact with the Sony is often frustrating compared to these other competitors.
First, the menu is not good. This isn't a complaint that is aimed solely at a video shooter's experience, as photographers are also starting to complain about Sony's rats nest of a menu system. Let's start there.
The content Sony is cramming into the menu of their cameras has dramatically increased since even the A7S II days. Side by side, the A7 III and A7S II share almost nothing in common anymore in this regard. It seems like there are twice as many things to select in the menu of the A7 III than the A7S II, and just about nothing is in the same location. To Sony's credit, coming from the A7S II and looking at the A7 III is like breathing a gasp of oxygen after holding your breath underwater for longer than you like. There certainly have been improvements, but the experience is still clunky.
For example, there is no reason for where they chose to put the "Format Card" option. It's in the middle of the pages dedicated to the "gear" icon, and it's then in the middle of the options on that page. Meanwhile, most everyone else seems to know to either put it on the first page or last page of that menu, and to make it at the top or bottom of the list for quick, easy access. Similarly, though S-Log 2 and S-Log 3 are included with the A7 III, good luck figuring out which of the profiles is which without consulting the manual, or Googling. For an inexplicable reason, Sony does not label their profiles in camera either. They simply list profile "PP1" through "PP10" in the menu, and it's up to you to figure out which is which. If you assumed that last two were S-Log, you would be mistaken. The correct answer is PP7 and PP8. This decision makes no sense at all, and it's incredibly frustrating as a user.
And while I am aware you can customize the camera to your liking to some degree and map specific options to the custom function keys on the body of the camera, out of the box, the A7 III doesn't aim to help you as a shooter at all. It lacks a quick menu to give you immediate access to frame rate options or picture profiles. Without mapping them manually (to either a custom Function button or into the My Menu page), you'll find yourself spending precious minutes digging through the convoluted menus in order to find the option you were looking for. For run-and-gun shooters, like wedding and event videographers, this is crippling.
4K Video Framegrab (click for full-res)
My last note on the camera's usability is the record button. While it's nice that it has been relocated on the newer Alpha bodies away from the edge of the grip and into a dedicated slot near the diopter, it's not the most "responsive" button I've used. I will press that button fully down, and that leads me to believe that a clip has either been started or stopped, but in several times throughout a shoot day that will not be the case. It's either a responsiveness thing with the camera itself, or the button doesn't work every time because I've missed shots multiple times thinking the camera was recording when it was not. I've also wasted space thinking I've stopped recording when, in fact, the camera continues to capture footage of my feet or jacket pocket.
It's gotten to a point where I have to remember to look down at the screen and actively watch the recording start and stop, which when shooting in documentary situations (my bread and butter) as a lone videographer is a real stress-inducer. It's not that I don't already have a ton of other things to think about, and remembering to make sure my camera is recording even after I press the record button down as far as it goes is... not fun.
The final takeaways
Though the Sony A7 III takes some truly beautiful video clips, especially when you consider its form factor, full frame video and technical specs for its $2000 price point, it's not perfect. Though it has some crazy video specifications like full frame capture with no pixel binning or line skipping and the ability to oversample when using Super 35 mode, these benefits aren't immediately noticeable due to the compression for SD cards.
The A7 III at best shoots 4:2:0 in 8-bit internally, and 4:2:2 in 8-bit to an external recorder via clean HDMI out. That's less than ideal, and even if you're oversampling or doing all that jazz with the sensor, that kind of color compression means you're not going to be able to take full advantage of those specs. Most colorists will tell you that shooting in Log isn't even worth it if you're not at least in 10-bit. Combining that with the compression internally that I just mentioned and despite the flashy tech specs, the A7 III isn't capable of actually delivering much more finished, visible quality than its competitors.
Standard Picture Profile: 4K Video Framegrab (click for full-res)
S-Log2 Picture Profile: 4K Video Framegrab (click for full-res)
However, that doesn't make the A7 III a bad video camera by any stretch. It's really quite wonderful that there are so many great video camera options that we can nitpick the way I am here. When you look at the high quality 4K video footage out of the A7 III, you're going to be happy.
Aside from having a tendency to crush the blacks, the A7 III footage looks really, really good. The in-camera stabilization is nice, the lens options Sony has for their full frame E-mount are substantial, and the A7 III is well-priced considering what it can do. Is it the best video camera for $2000? Probably not. But if you're already shooting Sony and looking for a B-camera, the A7 III more than fits the bill. Heck, I would shoot with two A7 III cameras today over two A7S II cameras. That should be saying something.
Follow Imaging Resource