Panasonic AJHDC27HP AJHDC27H User Guide - Page 63

Variable frame rate (continued) In this unit, the frame rate is set by changing the storage time of the optical signals sensed by the CCD. Depending on the frame rate setting, the following problems may arise. 1 White blemish White blemishes may be seen on the screen on account of the fluctuations in the dark current of the photodiodes which make up the CCD picture elements. This current increases in direct proportion to the rise in the CCD's temperature and storage time in the photodiode. In short, the white blemish increase in inverse proportion to the frame rate setting. When a lower frame rate setting is desired, reduce the master gain setting and, where possible, avoid direct sunlight and use the unit in a cool environment. When using this unit particularly at a low frame rate of 11 fps or less, the extremely small white streaks generated by the CCD are minimized using a special method. For this reason, when subjects with extremely small bright spots are shot, these spots may appear less bright. 3 Disturbed images The images may be disturbed for an instant when shooting while maintaining the frame-to-frame continuity of the scenes with the time code set to the rec run mode and with the frame rate set at 24 fps, 25 fps, 30 fps or 50 fps. This occurs in order to reset the video signals from the camera so as to maintain the continuity of the time code recorded on the tape. The disturbed images are not recorded on the tape but they will affect the signals which are output from the HD SDI MON connector. Similarly, the images may also be disturbed for an instant when the time code has been locked to external signals or preset while the frame rate is set at 24 fps, 25 fps, 30 fps or 50 fps. If the time code has been set to the free run mode, the images may also be disturbed at that instant when the frame rate is switched to 24 fps, 25 fps, 30 fps or 50 fps. However, the images will not be disturbed during recording even if the frame rate is switched to 24 fps, 25 fps, 30 fps or 50 fps. 2 Delayed response time in automatic processing When the frame rate setting has been lowered, it takes longer for the unit to perform the automatic processing (such as auto white balance, flare compensation, auto knee and auto iris), possibly giving the user the impression that something is odd or wrong. The response time for automatic processes is particularly slow at a frame rate of 20 fps and below. When the frame rate has been set to 20 fps or below, it is recommended that the unit be operated with the automatic processing released. 63