I know there are probably quite a few people who wonder just how much wider a 9mm lens is on micro 4/3rds compared to 14mm... I wondered this for a while since I typically record high school marching bands and drumlines and the standard 14mm width was just not quite enough.
Besides 9mm the other option at micro 4/3 was to go with a fisheye which guarantees a 180 degree view, but the fisheye barrel distortion is not desirable sometimes.
My equipment consists of a Panasonic G7 with the standard 14-140mm kit lens. With a 2x crop factor that basically made the lens a 28-280mm lens at 35mm. At 14mm the angle of view is about 78 degrees, but at 9mm it's abot 100 degrees. Knowing all these numbers and figures doesn't exactly translate into what you see so I took some pictures to compare below:
The following is the kit lens at it's widest 14mm:
And below is what the view looks like with a Olympus Zuiko 9mm:
Hopefully this will help people out who are looking for a wider angle without having to go for a fisheye lens.