The time code on the C100 runs "slower" than the clock on the camera.
I have a EOS C100 Mark I. I'm using the default settings which means the recording format is 24P and the system frequency is 59.94 Hz. I set the clock and hit "Set" when the real world time matches what I set. Then, I set the time code mode to "Preset" and run to "Free Run". I set the initial value to the clock time and again hit "Set" when the actual time matches what I've entered as the TC starting point. Since I'm configured with 24P recording, the DF/NDF is dimmed / not available but "DF" is displayed and the time code is all colon separators indicating the camera is using drop-frame.
Within an hour, the time code is many seconds behind the clock. The clock doesn't show seconds, but when displayed, the time flips to the next minute a few seconds before the TC advances. The difference gets worse each hours. And this is without turning the camera off.
By the way, the clock maintains accuracy to actual time, while the freerun timecode falls further and further behind so eventually, it may be actually by 4:51 PM and the clock will read 16:51 but the TC will be 16:50:00:00.
I understand drop-frame exists to compensate for the slower 23.976 frame rate. And, I believe that even though the C100 says it's shooting 24P it is really recording at 23.98. I can't uderstand why this discrepancy exists between the rate at which the camera's internal clock counts seconds and the TC advances. If the TC were actually dropping frames correctly, it seems it should match the clock time. If it is not, then the time code is non-drop and not drop, but the menu and display tells me it is drop-frame TC.
