2 Replies Latest reply on Feb 28, 2011 8:23 AM by Colin Brougham

    Combining resolutions and frame rates




      I searched the forum's and was unable to find an answer so hopefully someone can help me out!  I'm shooting sports on a Canon T2i and had a couple of workflow questions:


      I typically shoot at 1080p 24fps, but on occasion switch to 720p 60fps mid shoot for slow motion shots.  Currently when I work in post, i will use the 1080p 24fps sequence and when it comes time to use my 60fps footage, I enlarge the footage to fit the 1080p frame and then time remap the footage as I see fit (I understand enlarging the footage is comprimising the quality).


      My question is, is there a better, smarter way to do this?  Would it make more sense to capture everything at 720p/60fps and then slow the footage down in post?  I don't require 1080p for my final product, but I shoot at that res/frame rate because I require the 24p film-like feel.  If I shoot at 60fps but then export at 24fps, does it still give me the same effect?  Or do I need to manually slow down (time remap) 60fps footage?  If so is there a standard percentage to use?


      I appreciate any feedback, and will continue to research and experiment on my own.




        • 1. Re: Combining resolutions and frame rates
          Colin Brougham Level 6



          Here are a couple things you could try:


          1. Shoot at 1080/24p, but edit in a 720/24p sequence. Since you don't need 1080p output, you're not losing anything here, but actually gaining. You have a little bit of reframing capability with the 1080p footage in a 720p sequence, and it's pretty simple to scale the 1080p shots to fit the full frame of the 720p sequence. As you're clearly aware, it's better to decrease the size of a larger format than increase the size of a smaller format.
          2. Your time remapping workflow is fine, if you need variable speeds, but a quick way to match the frame rate of the 60p footage to the 24p sequence is to change its frame rate interpretation. Simply select one or more of the clips, right-click them or go to Clip > Modify > Interpret Footage, and look at the Frame Rate section. If you type "23.976" in the "Assume this frame rate" box, your footage will be interpreted as 24p and give you a nice 2.5:1 overcrank.
          3. Exporting 60p at 24p will not give you the 24p "look." Instead, you'll get a stuttered export, because Premiere will have to drop frames to conform the 60 frames per second to 24 frames per second. The first frame will make it into the export, followed by the third frame after that, and then the second after that, and then back and forth between the third and second frames--it won't look good You can export with Frame Blending turned on and interpolate these frames, but that will not look that good either.


          Hopefully, that gives you a little bit to work with. Experimentation will be the key here. Have fun!

          1 person found this helpful
          • 2. Re: Combining resolutions and frame rates
            rjpowell9 Level 1

            @Colin -


            Thank you so much, this is exactly what I needed to know.  I will implement what you've recommended and experiment to learn more.


            Thanks again!