IDS peak 2.8.0 / uEye+ firmware 3.33
Flickering in videos is a common problem that occurs when the frame rate of the camera does not match the frequency of the light source. The light appears uniform to the human eye, but the camera captures the rapid changes in brightness. This becomes visible in the form of flickering in the live view or in captured videos.
Reason for flickering
The sine wave (current) typically results in a half sine wave for the brightness of lamps, here as an example for 50 Hz.
Fig. 34: Lamp brightness with 50 Hz
So, the image brightness may vary if the frequency of the illumination and the frame rate do not match. Here an example of a capture at 30 fps with an illumination frequency of 50 Hz.
Fig. 35: Lamp brightness (50 Hz) and frame rate (30 fps)
Choosing the right frame rate allows flicker-free image capture, even if the lighting flickers.
Fig. 36: Lamp brightness (50 Hz) and frame rate (20 fps)
Flicker-free frame rates
Illumination with 50 Hz |
Illumination with 60 Hz |
|---|---|
|
120 |
100 |
|
|
60 |
50 |
|
|
40 |
33.333 |
|
|
30 |
25 |
|
|
24 |
20 |
20 |
|
17.143 |
16.667 |
|
|
15 |
14.286 |
|
|
13.333 |
12.5 |
|
|
12 |
11.111 |
|
|
10.909 |
10 |
10 |
|
9.231 |
9.091 |
|
|
8.571 |
8.333 |
|
|
8 |
7.692 |
|
|
7.5 |
7.143 |
|
|
7.059 |
6.667 |
6.667 |
|
6.316 |
6.250 |
|
|
6 |
5.882 |
|
|
5.714 |
5.556 |
|
|
5.455 |
5.263 |
|
|
5.217 |
5 |
5 |
|
4.8 |
4.762 |
|
|
4.615 |
4.545 |
|
|
4.444 |
4.348 |
|
|
4.286 |
4.167 |
|
|
4.138 |
4 |
4 |
|
3.871 |
3.846 |
|
|
3.75 |
3.704 |
|
|
3.636 |
3.571 |
|
|
3.529 |
3.448 |
|
|
3.429 |
3.333 |
3.333 |
|
3.243 |
3.226 |
|
|
3.158 |
3.125 |
|
|
3.077 |
3.03 |
|
|
3 |
2.941 |
|
|
2.927 |
2.857 |
2.857 |
|
2.791 |
2.778 |
|
|
2.727 |
2.703 |
|
|
2.667 |
2.632 |
|
|
2.609 |
2.564 |
|
|
2.553 |
2.5 |
2.5 |
|
2.449 |
2.439 |
|
|
2.4 |
2.381 |
|
|
2.353 |
2.326 |
|
|
2.308 |
2.273 |
|
|
2.264 |
2.222 |
2.222 |
|
2.182 |
2.174 |
|
|
2.143 |
2.128 |
|
|
2.105 |
2.083 |
|
|
2.069 |
2.041 |
|
|
2.034 |
2 |
2 |
... |
... |
Frame rates that are flicker-free at both 50 Hz and 60 Hz:
