Mixing different frame rates in a sequence

I have learnt since my poly years not to mix different frame rates in the same sequence as it will pose potential frame problems. However because of my quest to video flickering lights, it really challenged me to re-look into this issue.

I came to realise that not all flicker shows up on video despite it flickering in real life. It got me questioning my perception a little. However, I toggled around with the frame rates and realised that on 50fps, the flicker can be seen but not on 25fps.

So I took the risk to record on 50fps and decided to figure it out in post. I dragged and drop the 50fps footage onto a 25fps timeline, PremierePro (PP) will convert it automatically but I will lose my flicker as a result. So I almost wanted to use a 50fps timeline and drag and drop the rest of my 25fps videos into it. As I did that, the 25fps videos played fine but they are all bigger than my frame and I have to manually click ‘scale to frame’ for each individual video. That just wasn’t smart, not to mention I wouldn’t know if any thing may happen to my video when I export.

While searching for an answer, someone shared in the CreativeCow forum, that he tried to slow the speed of the 50fps footage (on a 25fps timeline) down by 50% to get the slow motion effect. That is not what I wanted, but I tried anyway, and the flicker came back! YESSSSS However it was in slow motion. -.- if I do not include any human movement, it would not be obvious, but I do have a man riding a bicycle in the shot.

After a few more links digging and trying, people recommended conforming footages to fit the timeline. So you double click your video in the project folder > Modify > Interpret Footage > set your desire frame rate. Surprisingly the conversion work with my flicker still intact! (I assumed it will be like my first attempt of drag-and-down to the timeline, but it wasn’t)

 

I tried exporting it with a 25fps footage and this is how it works out. I am going to try editing the videos together and hope it will not cause me any more issues.

 

Good week ahead~ Hope it helps anybody who is mixing different frame rates in the future.