Thoughts on the Panasonic GH4 and Sony a7S
This past summer, I shot two different short films on two of the currently most popular mirrorless DSLR-like cameras for low-budget filmmaking: the Panasonic GH4 and the Sony a7S. There are a million different comparison pieces and lengthy reviews out there online from many extremely talented and knowledgable people (Dave Dugdale from learningvideo.com has a great in-depth video on the two cameras here) and so this post is less of a review of either camera and more of an account of my experiences with each.
In June, I managed to bully enough friends and call in enough favors to put together a 7-minute sci fi film called TERRESTRIA. I shot this on the GH4 using the fantastic Veydra Mini Prime lenses and I was tremendously pleased with the results. Here's the trailer:
I spent a lot of time researching which camera I should rent for the shoot, pretty quickly whittling down the options to either the GH4 or the a7S. Both, according to the internet, were fantastic cameras with a lot of features; I couldn't really go wrong, especially considering the (relatively) low cost of a five-day rental in either case. I eventually settled on the GH4 for several reasons. Firstly, I already owned a GH2, so I should have already been comfortable navigating Panasonic's menus by the time it arrived, cutting down on any learning curve and saving valuable time. Secondly, I knew my locations wouldn't be battery-friendly (we shot out in the rural countryside for two of the three days, away from any charging station) so the GH4's reported superior battery life was an attractive feature. Finally, I really wanted to shoot as much as I could in 4K for the extra detail and reframing options it would afford me in post, and doing so on the a7s would have required the additional rental of an external recorder, which would have eaten up too much of my meager budget to ensure I had all of the lenses I needed.
So I ordered the GH4, Mini Primes (16mm, 25mm, 35mm, and 50mm) SD cards, extra battery, and nervously tweaked my needlessly-elaborate Excel spreadsheet until they arrived in the mail.
We shot the video, encountering only a few setbacks, thankfully. I might delve deeper into the specifics of making TERRESTRIA in another post, so for now I'll leave the tales of tornadoes and tears for later. The Panasonic functioned beautifully throughout the shoot, and I think I only had to swap the batteries twice the whole time. The flip-out screen was hugely helpful in lieu of any external monitor, and the focus peaking was a very welcome change from the eyeballing-and-hoping method of keeping focus I was used to with the Canon 5D Mark III. Neither of these features were surprises, obviously, but I found myself relying on them quite heavily.
The biggest unexpected plus from the GH4 -- something I must have overlooked/under-anticipated in my research -- was the quality of the 1080p 60fps footage, recorded at 200mbps. I have a huge fondness for the 60fps framerate, as I think it has a lovely look when interpreted at 24fps. It graded tremendously well and just looked fantastic with the slightly-customized Cine D color profile I used for much of the shoot. I ended up scrapping all of my 96fps footage, save for one shot that made it into the final cut. Like others have said, when you crank up the VFR settings that high, you really have to be in optimal conditions for it to look as good as the rest of your footage. Also, 96fps is just too much for what I was filming; slowing down the 60fps footage was perfectly fine for what I was trying to achieve.
Since I was filming in June 2015, I didn't have the recent V-Log firmware update, which seems to be getting a mostly-positive response from what I can tell. I was perfectly happy with the Cine D and Cine V profiles included on the base firmware, but if I were to purchase a camera I'd look more closely at the logarithmic profiles available across brands.
All-in-all, I loved the GH4. It was perfect for what I was trying to shoot, which is probably the highest praise someone could give a camera. I don't know if I'd buy one; the lack of built-in ND filters, no XLR input without a costly adaptor, and the more general drawbacks of the Micro Four Thirds sensor would push me towards a dedicated video-oriented camera body, but it fit my needs exactly for those five days in June. [Side note: I'm not actually as down on the Micro Four Thirds sensor as many others out there seem to be; I enjoy the aesthetic and the noise issue isn't nearly as bad as people are saying. The lens options for m4/3 are ever-expanding and there are already some great lenses out there: the Veydra Mini Primes are fast and sharp and flare nicely as well as being fully manual. I'd probably opt for a full-frame sensor myself, but there's nothing wrong with Micro Four Thirds. Calm down, everybody.]
Yikes, this is getting lengthy. Anyway, the circumstances in which I used the a7S were vastly different from when I shot TERRESTRIA. A friend of mine was going to be visiting for a few days from LA, and we decided we should shoot something quick while he was in town. We threw ideas back and forth for a while and eventually worked out a script we could shoot over two nights that would cost as little as possible. When it came time to place the order (we had an even smaller budget for this project) we found out our other friend who had agreed to act could only help out for one night. After a moment of panic, we decided to charge ahead and shoot it all in one night anyway, a decision only reckless idiots like ourselves could make.
With fewer hands on deck than TERRESTRIA, (we had a two-person crew: I was running the camera/acting in part of it and a fourth friend running sound) three times the cast, (admittedly, TERERESTRIA only has one character) half as much equipment, (we had to beg around for a shoulder rig and LED panel) a much stronger need for on-location sound, and only one night to shoot it all, we were in for a rough night. Surprisingly, we got all the shots we wanted and most of them were even usable. Our sound levels were low across the board but definitely salvageable, so I was caught in a near-constant relieved sigh as I edited together our poorly-conceived creation.
As for the a7S, it functioned... as expected. I knew battery life was going to be a big concern, but we were going to be near electrical outlets for most of the shoot so we weren't in dire straits.
Obviously, the big draw for the a7S is its low-light capability. We were going to be shooting a lot of night exterior shots so having that mystical ability to "see in the dark" was gong to help us out a lot. It should be noted that you can absolutely not see in the dark with this camera, but we didn't really expect to. I first saw the a7S at NAB 2015 in the big scary Sony booth where they set it up at some ungodly ISO, pointing at a trio of figurines you could barely make out with your unaided eyesight -- the point being to impress the unwashed masses (an uncomfortably-accurate term in my case... that week in Las Vegas was a week of many odors) with a clearer image of whatever knockoff nativity scene they arranged. In the moment, I was awestruck and vowed to purchase the a7S the very minute I paid off my student debt twenty or thirty years down the road. I returned home and began researching the camera, finding conflicting accounts of its brilliance and warnings of putting too much faith in the full-frame sensor. I realigned my expectations, erring towards being underwhelmed (exposing to the left, you might say) and that ended up being the right call.
The low-light capabilities of the a7S are phenomenal, don't get me wrong. You still have to know what you're doing, though, and you can't get carried away with cranking the ISO. You absolutely will get noisy images at night without proper lighting, but compared to not having a remotely usable image at all (something you'd run into with the GH4 if you filmed at night without good lighting) the a7S can be extraordinarily handy in the right circumstances.
Before returning the camera, I played around with some photography. Because of our budget restrictions, we were only able to rent a single lens, so I went with the Sony FE 28-70mm F3.5-5.6. The wire focusing was incredibly frustrating during the shoot, but when taking pictures the auto-focus was quick and I liked the results (photo at the end of the piece due to formatting issues; I can't figure out how to resize an image within a blog post because I'm a bumbling fool).
I liked the look of the a7s's 1080p 60fps footage and Sony's color science is just as good as people say. The menu system and body design are clumsy, frustrating, and unintuitive, but perhaps that's a byproduct of the alpha 7 series being a primarily photography-focused design. The flip-up screen is useful, but not nearly as versatile as the GH4's. The battery life was poor. I know people qualify the battery performance with "but they're small batteries" and yeah, I get that, but I just want good battery life. If Sony has to make a slightly larger battery/grip to get that extra performance, then I'll happily lug around that extra 0.2 oz.
It sounds like I'm being harsh on the a7S, but I don't mean to be. It worked for what I wanted it to do. I'm excited about the a7Sii, which seems to improve over the a7S in many ways, including internal 4K recording with the same low-light performance. I'd definitely consider using either the GH4 or the a7S again depending on the project, and having the experience this summer to make a more informed decision about which camera to use was helpful.