I came across this post on 43rumors.com – GH5 AF Video Improvement and it was interesting. Watch both videos. There is a noticeable improvement in autofocus using those settings. Real quick…if you haven’t heard people have been very critical of the autofocus performance of the Panasonic GH5 series during video recording. So basically people letting the camera keep continuously autofocusing during recording find the performance is VERY slow. So if you focus on a subject close to the camera and then want to refocus on your face for example… it would take forever. Or if you were moving around in frame the camera would not keep up.
Honestly, there are very few cameras out there that I find the autofocus performance in this respect that great anyways. The video discusses changing the shutter angle used in video which allows the camera to focus faster for some reason. I am assuming it is due to refresh times available at those speeds? Someone more technically adept in video can chime in below. Anyways, I though let me try this on my E-M1 mkII. Not sure if it made any difference. I didn’t feel like it did. However…I do notice that the C-AF lock seems to make a good difference.When in video mode, go to Menu – Custom Menu A1 – C-AF Lock – and adjust to +2 Loose. I use single point and face tracking usually. I found this works best so far for most video applications.
Then again, most of the time I shoot video I manually focus with peaking on. I’ve had good results that way.
If you want to play around with the technique listed in the videos, you need to convert shutter speed to shutter angle.
Multiply your frame rate by 360 and then divide by the shutter angle you want. You will get the proper shutter speed to use.
So 24fps with 180 degree shutter is 24×360 / 180 = 48. In this case 1/48 second shutter. 30fps with 120 degree shutter angle like the video would be 30×360 / 120 = 90. 1/90th second. You can also go the other way with the math to get the shutter angle. So 24×360 / 60 = 144. That is 1/60th of a second at 24fps is a 144 degree shutter angle.
Basically the lower your shutter speed the smoother video looks. The higher your shutter speed, the choppier it looks. If all the math is too much, just roll with the common 2x your FPS is where to set your shutter speed for a nice look. Then use a Variable ND filter to control how much light enters. Video is a whole other world! Anyways, have you found anything that works better when shooting video with autofocus?