MPC-HC: fullscreen refresh rate change necessary (purpose)?

[flashandpan007]

Hi,
I've heard that it is possible to change the refresh rate of the Monitor at fullscreen in MPC-HC.

Everything is fine at 1920x1080p60 (my current setting for everything), but not if I enable autochange to 24p:
stuttery, cut off picture (overscan looking problem), strange colors and sharpness (I don't know how to describe)

So why is there the need to change it to 24p for 23,976p files (and the other refresh rates), when everything is fine at 60p for every file I play it with (flv, mkv, mp4, ........)

At the moment I don't get it. But I hope someone will explain me why people do this.

Thanks

[jagabo]

To display 24 fps material at 60 fps each film frame has to be displayed for multiple 1/60 second frames. This is usually accomplished by alternating between 2/60 and 3/60 seconds (2.5/60 seconds on average, ie, 1/24 second). That creates an obvious judder when there are smooth motions on the screen. You get smoother motion if you display the video at 24 fps where each frame is displayed for the same amount of time. Most monitors wont accept input at 24 Hz though. And many that do simply convert to 60 fps internally, leading to the same judder.

See the video in this post for an example of 24 Hz on a 60 Hz monitor judder:

https://forum.videohelp.com/threads/307004-Best-framerate-conversion-%28eg-23-97-to-30-...=1#post1888926

Watch it full screen for the biggest impact.