I just shot a small Jewelry commercial for which we chose the Panasonic GH5 (why we chose that camera I will explain in an upcoming post). I knew I had to use the autofocus for some gimbal slow-motion shots so together with co-director Noah Hähnel I did a quick test the afternoon before. We used the Lumix 12-35mm f 2.8 lens shooting wide open. In the video below you can see the results of our test (and the settings we went with for our shoot):
The camera was recording in 1080 50p, 422 10 bit in V-log color profile. The Panasonic LUT was applied in editing.
The GH5 offers a couple of different AF modes of which we tested the Face/Eye Detection, Tracking, 225-Area and 1-Area modes. We also played around with the AF speed and sensitivity settings (which you find in the settings menu).
The problem with the Face/Eye detection is that as soon as the person you are shooting is turning his/her head too much it looses the eyes and won’t focus anymore. Sometimes it did recognize the face, but still would not focus. For our purposes we found that the Tracking mode worked best for us.
When it comes to the settings we went with Speed +0 and AF Sensitivity +2 for our shoot. If the speed was too high the focus kept pulsating/pumping, even if the object wasn’t moving. If it was too low it took too long to focus (which would not work for our slow motion shots). When the sensitivity was set too low, it took the AF too long to react. Sometimes it wouldn’t react at all.
Aforementioned settings (Speed 0 and Sensitivity +2) worked best for our scenario. We also found that the AF had trouble holding focus in slightly darker light. The GH5’s AF worked in most of the shots we really needed it for but it isn’t close as good as the Canon Dual Pixel AF in the Eos 70D (you can see my autofocus test for the 70D here). Panasonic promised to improve the AF in the upcoming firmware (end of September).