Frame Rates for slow motion

DatoAliffAlex wrote on 6/21/2017, 11:25 AM

Is it really important to set your project Frame to get smooth slow motion?

 

*My English is quite terrible,so don't go hard on me :v

Hello,Im just bit curious about setting up my project settings.I try to make a super smooth slow motion video.I always shot all of my video in 60FPS or 50FPS.Then in Vegas,I will set my main project settings into 25FPS. And I will basically slow down my 60FPS video into 50% with "Velocity map".So I will get a smooth 30FPS slow motion video.So the question is, the slowed down video will be exported as 25FPS will look Smooth,so what if the slowed down video were exported on 50FPS settings?

 

I've already tried it out by myself, to see for for myself whether there's any difference.And they both look, smooth as what its supposed to do?

So I got a 50FPS video clip that last for 00:00:05.30, which is 5.3 second.so I slowed it down 50% and export it in 25FPS.The video last 11.10 second.

Then I use the same clip and slowed it down again on 50%,but this time I export it at 50FPS.An the video last 11.10 second too.

So basically I was told that if my project frame rates settings were lower then slowed video it will look smooth,and If my project frame rates settings were still the same as the video original frames rate,my slow motion will not last longer..but Both video I tried get same amount of time? Somebody please explain why

Comments

fr0sty wrote on 6/21/2017, 4:08 PM

The video will take the same amount of time regardless of frame rate, as you're still dealing with X amount of frames per second, meaning no matter what that number is one second of video is still one second of video. That said, I wouldn't see why stretching 50 frames per second to 25 per second over 2 seconds, then boosting it back to 50 (which would just result in frames being doubled) would result in any better quality than just rendering 25fps on the final output. In fact, because you have twice the frames, if you aren't increasing the bitrate as well on your output format (assuming it is lossy), you are actually losing quality.

Last changed by fr0sty on 6/21/2017, 4:09 PM, changed a total of 2 times.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

DatoAliffAlex wrote on 6/22/2017, 7:17 AM

The video will take the same amount of time regardless of frame rate, as you're still dealing with X amount of frames per second, meaning no matter what that number is one second of video is still one second of video. That said, I wouldn't see why stretching 50 frames per second to 25 per second over 2 seconds, then boosting it back to 50 (which would just result in frames being doubled) would result in any better quality than just rendering 25fps on the final output. In fact, because you have twice the frames, if you aren't increasing the bitrate as well on your output format (assuming it is lossy), you are actually losing quality.

Hmm still bit confusing...so do you think its Better for me to just export 60FPS/50FPS video into 25FPS for better slow motion?