Do digital cameras support 4K 120 recording at normal speed?

[KEIN NEIN]

Hi.

 

Nowadays I see in the specsheets that there are digital cameras capable of recording 4K 120 FPS (and 4K240/8K120 in film cameras like the Ursa). But I wonder, is 4K 120 reserved for slow-mo video? Or does it work in normal speed as well?

 

I ask because I searched video tests in YouTube and I only see slow-motion when it comes to 4K100 or 4K120.  It's due to 4K100+ being slow-mo only or YT not supporting 120 FPS or simply because most people only use the 4K100+ feature for slow-mo footage?

 

Thanks.

[tkitch]

you can play 60 or 120 fps video, but it has to be encoded to do that specifically.

And you probably can't stream it, because I don't think most sites do over 30.  (Some may do 60 for "premium" stuff.)

 

So, yes?  But also "not really functionally"

[KEIN NEIN]

1 minute ago, tkitch said:

you can play 60 or 120 fps video, but it has to be encoded to do that specifically.

And you probably can't stream it, because I don't think most sites do over 30.  (Some may do 60 for "premium" stuff.)

 

So, yes?  But also "not really functionally"

Which means (I guess) that you can do 4k120, but only to watch it yourself, provided you have a display that has a high enough refresh rate.

[Electronics Wizardy]

Yea many cameras can do that. You can also take the slo mo footage and speed it back up to real time. 

 

But there really isn't a distrubiution system for video over 60FPS, so basically no one shoots 120fps and delivers at 120fps as almost nothing can play it. And with stuff like motion blur you can get away with less FPS than video games often for a simmilar smoothness.

[Alex Atkin UK]

14 minutes ago, KEIN NEIN said:

Hi.

 

Nowadays I see in the specsheets that there are digital cameras capable of recording 4K 120 FPS (and 4K240/8K120 in film cameras like the Ursa). But I wonder, is 4K 120 reserved for slow-mo video? Or does it work in normal speed as well?

 

I ask because I searched video tests in YouTube and I only see slow-motion when it comes to 4K100 or 4K120.  It's due to 4K100+ being slow-mo only or YT not supporting 120 FPS or simply because most people only use the 4K100+ feature for slow-mo footage?

 

Thanks.

You misunderstand, shooting 120fps is always real-time.  You get slow motion by playing it back at a slower speed.

 

So the faster the frame rate your camera can capture, the slower you can play it back with it still looking smooth.

[KEIN NEIN]

19 minutes ago, Electronics Wizardy said:

Yea many cameras can do that. You can also take the slo mo footage and speed it back up to real time. 

 

But there really isn't a distrubiution system for video over 60FPS, so basically no one shoots 120fps and delivers at 120fps as almost nothing can play it. And with stuff like motion blur you can get away with less FPS than video games often for a simmilar smoothness.

Excuse me, English isn't my native language. Are you implying that high-framerate recording doesn't feel much more fluid due to motion blur?

[Electronics Wizardy]

Just now, KEIN NEIN said:

Excuse me, English isn't my native language. Are you implying that high-framerate recording doesn't feel much more fluid due to motion blue?

It will feel more fluid than a lower FPS, but a video at 60fps will typically feel more fluid than a game at 60fps due to motion blur. 

[tkitch]

4 minutes ago, KEIN NEIN said:

Which means (I guess) that you can do 4k120, but only to watch it yourself, provided you have a display that has a high enough refresh rate.

most of the time yeah.

Or you can upload to a file host and let people download the whole video (not streaming)

[KEIN NEIN]

2 minutes ago, Alex Atkin UK said:

You misunderstand, shooting 120fps is always real-time. 

Do you mean, capable of shooting 120 fps means capable of 120 fps real-time in camera especifications?

 

I see phone specs and there are specs for real-time and specs for slow-mo.

[KEIN NEIN]

3 minutes ago, Electronics Wizardy said:

It will feel more fluid than a lower FPS, but a video at 60fps will typically feel more fluid than a game at 60fps due to motion blur. 

 

7 minutes ago, Alex Atkin UK said:

You misunderstand, shooting 120fps is always real-time.  You get slow motion by playing it back at a slower speed.

 

So the faster the frame rate your camera can capture, the slower you can play it back with it still looking smooth.

So I assume the reason for 120/240 fps recording being a thing is the same reason why 8K/12K is available. Not because people will watch in that format, but because it's handy in post.

[Electronics Wizardy]

Just now, KEIN NEIN said:

 

So I assume the reason for 120/240 fps recording being a thing is the same reason why 8K/12K is available. Not because people will watch in that format, but because it's handy in post.

Yea, >60FPS is pretty much only used for slo mo as almost nothing can distribute >60FPS content. 

 

As far as recording, if the camera says it can do 120, you can get 120 out of it. Some will record in 120, but mark the file for 30fps as 1/4speed slow mo, but you can speed it up in post. Really up to the specific camera.

[Alex Atkin UK]

7 hours ago, KEIN NEIN said:

Do you mean, capable of shooting 120 fps means capable of 120 fps real-time in camera especifications?

 

I see phone specs and there are specs for real-time and specs for slow-mo.

The reason they have different specs is that more fps usually means they have to reduce the resolution.  In slow-mo mode it likely will also not record audio, to save processing power (and its useless when playing back slowed down anyway).  But in all other respects, the only difference is that in slow-mo its playing back the video at a lower fps than it was recorded in.

 

High-end slow motion cameras record at millions of frames per second which is really fascinating to see.
https://www.youtube.com/channel/UCUK0HBIBWgM2c4vsPhkYY4w

[TheNuzziNuzz]

Another aspect being overlooked here is the shutter speed of the camera while recording. Generally you want a shutter twice as fast as your frame rate.
So for 30fps you use 1/60th, 60fps: 1/120, and for 120: 1/240.

 

When using too slow a shutter, the motion blur while negate much of the benefit you might get from higher refresh rate. This also means you have to correct your exposure for the faster shutter speed. This can result in a tricky situation for a videographer - especially a novice one. 

While shooting on my A7s III (regarded as one of the best low-light lenses in it's price class) with entre level lights, ISO 12,800 in Slog3, and a fast f/1.4 lens, my exposure, going above 1/120th would significantly underexpose the image, requiring me to crank up the ISO (dramatically reducing image quality and dynamic range) OR add more high-quality studio lighting to the space.

 

My camera can even do 240 fps at 1080p!