Video 120p

[Dominique]

I made video in 120p, but image is really not sharp as 50p or 4K.
I did some tests in auto, and manual by adjusting the shutter speed 120 and 240 but without result. What do you think about?

 

[CThruU]

I made video in 120p, but image is really not sharp as 50p or 4K.
I did some tests in auto, and manual by adjusting the shutter speed 120 and 240 but without result. What do you think about?

Because you can only do 120 fps in lower quality settings. 4K will always be sharper.

 

[Dominique]

Still very surprising because the resolution is 1920x1080 as 50p,
but the difference is very important.

 

[CThruU]

Still very surprising because the resolution is 1920x1080 as 50p,
but the difference is very important.

Yes. 4K has 4 times number of pixels than 1080p video. Frame rate is more important for motion and doesn't affect resolution or picture "sharpness." Also, at 120fps you will be watching the resultant video at 1/2 speed slow motion unless you edit in post. Of course, very little reason to do that when you can shoot at 60fps. After experimenting, I've settled on 3840x2160 at 30fps for most of my shooting.

There are plenty of better photo/video people on here, so maybe someone can further explain, clarify or contradict my info. Happy to read more if I'm wrong about any of this.

 

[jwt873]

120 FPS is for slow motion. They can't use the whole sensor because the P4 camera system doesn't have the bandwidth to transfer 1920x1080 @ 120 frames per second.

When you select 1920 x 1080 @ 120 FPS, they get around the bandwidth issue by not using the whole sensor. This results in having less resolution than the normal 1080P and as a result the video isn't as sharp.

As far as I'm concerned, 120 FPS is a gimmick. They cobbled it together so they could add it as a feature. I find I can get the same quality slowing down video while post processing.

 

[Geoff G]

If you're comparing 1080p using a windowed sensor (120fps), with 4K they should look the same quality size for size i.e. the 1080p is the same as the middle of the 4K frame. You can see that in Adobe Premiere for example by telling it not to "scale the image to frame size" .

The situation comparing windowed video shot at 1080p to full sensor 1080p video seems to be more confused because it depends how the system does the conversion to reduce the 4K sensor data to 2K. Some use line skipping, some use pixel binning and the best ones downsample the native 4K image. Using the full sensor gives a better depth of field and less noise (although I don't know whether this applies to other than downsampled images).

Windowing the sensor makes it mobile phone quality (1/4" sensor) but if you need the telphoto effect and slo mo it's probably a price worth paying.