New C100 MKII Video bit rate problem

[Ben Moore]

Long Story short...... my new C100 MKII seems to be recording at incorrect bit rates. When I set the Camera to record 24 Mbps Im only getting about 17Mbps. When I set it 17Mbps I'm only getting about 10Mbps. I do realize that these bit rates are variable, but this a drastic difference. I also own a MKI and the bit rates from that are spot on with what they should be. (I'm not using nor have I tested .mp4 rates on the MKII)
So I'm hoping a few others might post bit rates they are getting from their MKII's so I can figure out if this is a inherent problem or just a problem with my specific camera.

[Gary Huff]

What are you using to determine the bitrate?

[Ben Moore]

I used both both Windows 7 and Windows 10. (right click>properties>details)

I filmed multiple hours of multicam footage with both the MKI and the MarkII, with both set to 24Mbps. The file sizes are drastically different. At first I thought maybe better compression on the MKII? but 24Mbps should be 24 Mbps so I dont think so....... This is what led me to look into and do more testing.

[Noa Put]

You might try mediainfo (https://sourceforge.net/projects/mediainfo/) which gives you a much more detailed overview then what windows offers.

[Ben Moore]

Thanks Noa! I downloaded it. A great tool for sure.

Sounds like these data rates are correct as I received the following response from Canon:

"These numbers sound about right, assuming a fairly well lit and stable scene. The older C100 did not use the same optimized variable bit rates that the C100 Mark II does, and therefore did use a bit more data per second than the newer C100 Mark II. The C100 Mark II can capture the same scene with the same detail while getting more footage in the same amount of storage media in many cases. You'll notice the bit rate jumping up toward the maximum bit rate if you have a busier scene with more detail and movement and a higher gain level"

The scenes I shot where extremely well lit and stable, so no issues i guess..... :-)

[Gary Huff]

I was on a shoot with two Ki Pro Minis and both were recording ProRes HQ, yet one was nearly half the file size of the other of similar lengths. I investigated to made sure everything was properly set, and it was, and everything went fine in post. It's just the wonders of compression.

AVCHD is done in hardware via the encoder chip, so highly unlikely that it would have been defective only in that way without affecting anything else. I also felt that the C100 Mark II's AVCHD compression was much better, visually, than the C100 Mark I.

[Seth Bloombaum]

For a test, you could shoot tall grass or tree leaves blowing in the wind, or crank up the gain until you see a maximum of noise, or shoot as jerky handheld as you can.

Those scenes in which every pixel changes on every frame ought to exercise the full bitrate!