| Time code: Drop Frame | |
| Colour video was slowly introduced into broadcast. |
| It was therefore necessary to make it compatible with black and white receivers and design colour receivers or televisions to be able to receive black and white programming as well. |
| In order to accomodate the extra information needed for colour the black and white 30 frame/second rate was slowed to 29.97 f/s for colour. |
| Although usually not an issue for non-broadcast applications, in broadcast, the small difference between real time (or the wall clock) and the time registered on the video can be problematic. | Over a period of 1 hour (SMPTE) the video will be 3.6 seconds or 108 extra frames longer in relation to the wall clock. To overcome this discrepancy drop frame is used. |
| Drop frame: Every frame :00 & :01 are dropped except for minutes with 0's (00:, 10:, 20:, 30:, 40: & 50:) |
