Several years ago I wrote Videography part 1, showcasing my lack of understanding of video as well as a pretty cool stop motion film I shot in Maastricht with two fellow students of the Fotoacademie, now defunct. Gotten ever so slightly wiser because of my current vlogging on YT, it is time for the second part: a review of the Sony A7 as video camera.
The short version: shooting video with the A7 is crap. I bought an action cam (DJI Osmo 6) when I started vlogging. Quality-wise it runs circles around the Sony at a fraction of the cost. So why did I continue to yearn to shoot video with the A7 and what was the biggest frustration every time I actually did?
Where the Sony A7 shines with video
Because you can mount different lenses on it, like the great Voigtländer 35mm f/1.2, that I still have not reviewed, you can create stunning shots not at all possible with any action camera. The depth of field and sharpness can be controlled perfectly, this ability is further enhanced by the size of the full frame sensor. Of course it is not a true video camera, so without a proper rig you are fumbling around a bit but with practice come reasonably steady shots. Some movement in the shots can be considered a style rather than a defect, a style I happen to like.
By changing lenses you can create virtually unlimited atmospheres, from hazy classic portraiture to sleek modern shots to crazy fisheye views and even toy landscapes with a tilt shift. Moving the plane of focus during a shot is one of my favourite tools, directing attention of the viewer through the scene and adding a peaceful dynamic feel in otherwise static situations.
Full manual control of the exposure is one of the big pluses over an action camera. While shooting you can easily change shutter speed, ISO and / or aperture to suit your preference. They will stay fixed unless you change them again.
The frustration
After the shooting comes the frustration. The Sony A7 has a terrific CMOS sensor that is perfectly adequate for photography, I continue to stand by that. However, the video part of this machine sucks ass. It only records 8-bit color channels, it has no proper gamut (color space) or gamma (often referred to as D-Log). Yes I am showcasing my lack of understanding videography again.
So after loading your potentially gorgeous shots in your editing software you cannot color-correct them sufficiently, channels clip or show artefacts with the slightest tweak. Especially reds are a b•tch. The neutral video looks ok and you should probably use it as such, but when mixing it with other video or when you are after a certain mood this is severely limiting. Starting with a standard chain of correction the whole image instantly looks off. I keep trying to get it ‘right’ but that seems impossible with the recording quality of the Sony A7. A big waste, imho.
You could attach a recorder to the hdmi output of the A7 to record in a better quality. But still the 8-bit limitation and lack of proper colour space remains, only the compression is gone.
Light on the (video) horizon
The original A7 has, despite the lengthy menus, almost no video settings. Only the audio level can be set and a couple of video quality parameters. Nobody really knows in what space this thing is recording, as you cannot set it. But this camera is over 10 years old and a lot of new stuff happened.
The A7 mark IV seems the first Sony Alpha with proper video functionality using 10-bit 4:2:2 recording. It can also shoot 4K but when you want 4K at 50 fps it uses a smaller portion of the sensor to prevent overheating, hence you are stuck with a 1.5 crop factor. Still way better than my old A7 which does 8-bit 4:2:0 and only 1080p at 25 fps. Can’t do any cool slomos with that and it’s a lot less sharp than my basic action cam.
The IV also offers a professional codec (XAVC-I), at the cost of storage you get a lot less compression. Still rolling shutter on the IV though (as on my original model), which distorts the image during quick (lateral) movements, e.g. when following a fast subject. I don’t use the A7 for that and my action cam exhibits rolling shutter as well, so meh.
I want 10-bit 4:2:2 and 4K @50fps
My original problems and the reason to qualify video recording with the A7 as ‘crap’ have to do with colour correction and other video post-processing. 10-bit has 4 times as many values as 8-bit, making transitions between bright and dark parts a lot smoother. The 4:2:2 part means it samples more colour, twice as much as 4:2:0 to be exact, even though it still skips pixels that are only used to measure brightness. Combined with 4K (vs 1080p) it means each frame contains a lot more colour information, which helps prevent loss of it during editing. Combined with professional gamut and s-log support it is to be expected you can distill more natural colours from the video, by mapping the values to a known colour space first.
The 50fps is only wanted to create beautiful slomo (slowmotion) shots as b-roll. Something I have not been able to do so far.
The final mark
Looks like the A7S mark III (and sibling FX3A) are the better video cameras of this moment, with full frame Sony E-mount. But they come at a hefty price. The A7 mark V does everything a lot better than my lowly original A7 at half the price of those video monsters. It lets you shoot decent photos as well, presumably even better than my first generation model.
So ok. Conclusion. Contrary to what I wrote before, I do not recommend the Sony A7 for video work, not until at least the mark IV version, and even then… Just get the mark V or the video offering (if your money is plenty and you have a separate beast for photography). Currently I am debating whether to continue to try to squeeze every last faded jagged f•cked up pixel from the original A7, video-wise, or just accept that it won’t work.
Or maybe Santa reads this post, and my woes will be over soon (yes, I’ve been very good this year).