What is the difference between 50p vs 50i in frame rate?
- FrankLv 77 months ago
The "p" stands for progressive and the "i" stands for interlaced.
Here's a link to various articles and videos that go into depth on the various differences: https://www.google.com/search?client=opera&q=diffe...
- Russ in NOVALv 77 months ago
50p builds the entire video frame 50 times a second. 50i is interlaces so it only builds a frame of every other line 50 times a second, so effectively the entire frame is only built at 25 times a second. Interlaced video is effective for crt type displays where the phosphors would persist longer and it means less information has to be transmitted for analog TV signals.
A frame rate of 50 times a second was arrived at because the power in Europe tends to be 50 Hertz (again probably arrived at during early crt technology). In the US, the standard frame rates are 60p and and 60i because the power is 60 Hz.
It is worth noting that analog crt tvs produced the image by scanning beams across the screen in lines left to right and top to bottom illuminating one pixel at a time. The persistence of the phosphors ensure the entire frame would be complete before they started to noticeably dim.
Most moves are filmed at 24 frames per second (24p) and digital media tends to preserve that if the tv/monitor supports that frame rate. Otherwise it will upscale it to whatever the monitor supports.
The human eye/brain looses distinction between frames at around 16 frames per second.