The GH4 is a great camera for video. It has all the features that the A7S II has except for the low-light abilities, the in-built stabilisers and it’s just beaten in the high frame rate camp. The GH4 can manage 96fps at 1080 while the A7S II can do 120fps at 1080. The A7S II also has S-log, whilst the GH4 has just had V-log introduced except it’s a $99US firmware update, so it’s not something that everyone has or may get.
Having said all that, the three things that the GH4 really has going for it over the Sony are its software (Sony really don’t know how to make a user friendly interface); it’s price, which is almost half that of the A7S II body only; and its output over HDMI. The A7S II outputs 8bit 4:2:2 and the GH4 outputs 10bit 4:2:2 and what those numbers mean is that is you’re using an external recorder over HDMI, the GH4 will output more colour information so you have more to work with when grading your footage in post.
The A7S II will still beat the GH4 hands down in low light, so if you’re an event shooter, this choice is still a no brainer.
Battery life is one area that just about any camera is going to beat the A7S II in. I have 3 batteries for my GH4 and those will last me an entire day with juice left over. I have 8 batteries for my A7S and they just about get me through a whole wedding shoot, which would be 10-12 hours.
It’s a small thing and probably most people wouldn’t notice it, but I shoot a lot of time-lapses. The built in time lapse function on the GH4 is easy to setup and use. The $10 time lapse app that you have to buy for the A7S and I assume A7S II, well lets just say it sucks and that’s the nicest way I can describe it.
I’ve owned and used the GH4 and A7S I since they both came out last year and asking me to choose between them is like asking me to choose between my kids, once I have another one, kid that is. I love them both for different reasons. Now that the A7S II has come out, it would appear that most of the advantages that the GH4 had over the I like internal 4K and high frame rates at 1080 have been added to the A7S II and so maybe I should just sell my GH4 once I get the A7S II. That would make sense, but I have to admit that I really love that little GH4.
Of course that is just comparing the GH4 to the A7S II on paper, I’ll be able to make a better decision once I have one and I can play with it.