Yesterday four Panasonic GH5s finally arrived at the Fstoppers studio and I spent all day playing with the cameras. As you may have heard, we have decided to finally switch from shooting videos on Nikon DSLRs and the GH5 is quite an upgrade. There seems to be one major issue though... The auto focus while recording isn't reliable.
Let me first start by saying that the autofocus before recording works great and I can't tell that it's any slower than using a standard high-end DSLR. I was extremely impressed by how many different AF options there were and how quick and accurate they each were. Once that camera begins recording however, everything changes. If you're filming, AF seems to have a mind of it's own. Sometimes it quick, sometimes it's slow, sometimes it hunts constantly even if the subject is totally stationary, and occasionally it won't focus at all. What makes this even more strange is that at times the camera will create a box over your subjects face (in face detection mode) showing that it does in fact know where the subject is, but it still won't focus. I would have made a video about this myself but Max Yuryev made a great video that goes into extreme detail about these issues.
At this point the AF issues with the camera seem to be software based and perhaps they could be fixed with a simple firmware update but to complicate things even further, some GH5 users are claiming to have excellent AF results during filming. Check out the impressive performance of the GH5 in this studio environment.
This has some GH5 owners wondering if there are actually hardware issues with some or all GH5s that will not be able to be fixed with a firmware update.
I personally have never used continuous AF while recording. I like my focus to be locked off because I don't trust that the camera will hold focus perfectly but that may be because I haven't ever used a camera with quality continuous AF. This focus issue with my GH5 has led me down a path of comparing continuous AF while recording with Canon and Sony cameras and I had no idea just how good AF could be. Check out this side by side comparison of the GH5 and Canon 80D.
The Canon's AF is absolutely incredible. Apparently it has on-sensor phase detection which allows it to focus so quickly while recording and the GH5 only has contrast AF which would explain why it works better recording in 60fps rather than 24.
If the GH5s AF is looking pretty pathetic to you at this point, wait until you see what Sony's cameras can do.
The continuous AF in both Canon and Sony cameras are so good that I could certainly see myself using it while filming and the GH5 is so spotty that I don't think I could ever trust it.
Why I Still Don't Regret Switching to the GH5
If I was filming a bunch of stuff by myself or vlog style videos, the GH5 simply wouldn't work. The AF is too slow and too unreliable to assume that it's working correctly. Obviously I'm hoping this is all a software issue that will be resolved with a simple update but even if it never is, it's not a deal breaker for me. Nikon's continuous AF during recording was always so bad I never even attempted to use it and so I've come up with a system for recording videos that doesn't rely on AF. In fact, I don't know any professional videographers who use AF (other than to get the initial focus before filming). Most cinema cameras don't have any sort of AF at all.
And when it comes to manually focusing, the GH5 is far superior to any Nikon I have used. The screen will "punch in" to 100% so that you can more easily see what you're focusing on and focus peaking will put colored lines around in focus areas of sharp contrast. It may not be an upgrade from a current Canon or Sony camera, but coming from Nikon, it's a huge jump.
Stay tuned for many more posts about the new GH5. I'm learning so many things every day and I will relay the best information back to you guys here at Fstoppers.