Saturday, 8 December 2012

GH3 video example @ ISO 6400

The Panasonic GH3 camera improves upon the GH2 in many ways. One improvement is that you can record videos at ISO 6400 sensitivity, while the GH2 only went up to ISO 3200.

This is quite useful. Some months ago, I was recording fireworks, and found that even with ISO 3200, I had to set the shutter speed to 1/12s, and record at only 12 frames per second. With the GH3, I could have set ISO 6400, and used 25 frames per second, a very common FPS setting.

I have tested the ISO 6400 setting at a dimly lit concert. I used the Lumix X 12-35mm f/2.8 lens at 35mm f/2.8. The video mode was the 1080p, 50 fps, and I set the shutter speed to the slowest possible, 1/50s. Here is the result:

In this case, I could probably have gotten better results by using 25 fps, allowing for 1/25s shutter speed, and reducing the ISO to 3200. But here I wanted to test the ISO 6400 setting.

Note that the lightning at the concert was very difficult, with a lot of red coloured lights. With better lightning, the video outcome would have been vastly better.

Here is an extracted frame from the video. I used Kdenlive in Linux to edit the video:

The video mode I used is denoted "MOV FHD 50p" in the camera, and gives 1920x1080 image frames at 50fps. On an NTSC camera, the fps would be 60. This mode gives you 50Mbps bitrate, about twice as much as the highest bitrate the Panasonic GH2 could produce.

For the ultimate in image quality per frame, you could choose the "MOV I FHD 25p" mode, which encodes the video as ALL-INTRA, with a bitrate of 72Mbps. Again, on an NTSC camera, this would be 30p, not 25p.

1 comment:

  1. You should white balance in camera for available light this can be done manually. This is better for video than auto white balance that can have problems in low light !! Panasonic cameras have a special setting for a white card once set remains in memory !!