Solution
These modes are associated with analog cameras. For standard analog cameras, the lines of the CCD are interlaced to increase the perceived image update rate. This means that the odd-numbered rows (the odd field) are scanned first. Then the even-numbered fields (the even field) are scanned. The two fields make up one frame.
| Comparison Chart |
| | NTSC | PAL |
| Abbreviation | National Television System Committee | Phase Alternation by Line |
| Video Bandwidth | 4.2 MHz | 5.0 MHz |
| Sound Carrier | 4.5 MHz | 5.5 MHz |
| Bandwidth | 6 MHz | 7 to 8 MHz |
| Vertical Frequency | 60 Hz | 50 Hz |
| Horizontal Frequency | 15.734 kHz | 15.625 kHz |
| Color Subcarrier Frequency | 3.579545 MHz | 4.433618 MHz |
| Lines/Field | 525/60 | 625/50 |
Analog cameras are low in cost and easy to interface with a standard analog acquisition device. Therefore, they can solve numerous applications at an attractive price. However, Industrial digital cameras are the popular choice for machine vision, scientific imaging, and automated test systems. If you already have an analog camera system, NI makes it easy to migrate to digital. If you prefer analog cameras, NI offers several options below to help with your applications. Please ref. the related links section to know more.