For this tutorial, I'm using the Mixed_Frame_Rates.prproj file.

You can find that project file with the media associated with this tutorial.

Just double click on the project file to open it in Premiere Pro CC.

There are several common footage frame rates.

If the frame rate doesn't match your sequence frame rate, you're going to have to make some decisions about how the footage is going to be conformed.

And that's exactly what happens when you add a clip to a sequence that doesn't have matching settings.

Either frames will be dropped, or new frames will be generated to fill in some gaps.

Remember that footage is made up of a series of frames.

You can play them at any speed you like.

This is a 24 frames per second piece of video of the rooftops of New York.

And it's worth noting that regardless of the settings for your sequence, you'll always see the native frame rate in the Source monitor.

This is a really useful way of comparing and contrasting the results of any speed change adjustments you've made in a sequence.

The sequence I've got open right now is set to 30 frames per second.

And as you can see from the Frame Rate heading here and in fact the names of the clips in the Project panel, I've got some 24 frames per second and some 96 frames per second media.

But interestingly, you'll notice that this 96 frames per second media, well, that information is just in the file name really, is still listed as 24 frames per second in the Project panel.

And that's because though I happen to know that that footage was recorded at 96 frames per second, the camera has a second frame rate setting which is the system frequency or the system frame rate.

That stream of frames will play back at the frame rate set by the camera, in this case 24 frames per second.

The result is in this case of course we get slow motion.

I'll just double click on one of these to open them up and you can see if I play, the result is very slow movement.

This type of slow motion is beautifully smooth because we're not generating additional frames of content, we're not adding gaps, the camera actually ran four times faster and now we're playing back at normal speed.

Still, I'm going to take one of these 24 frames per second pieces of media and drop it into my sequence.

And right away, you see I'm getting this Clip Mismatch Warning.

Premiere Pro CC is letting me know that the clip doesn't match the sequences settings.

You're only going to get this warning once and it's the first time you add a clip to an existing sequence.

I can choose to change the sequence settings to match the clip but, on this occasion, I want to keep the existing settings.

Without me doing anything else at all, Premiere Pro CC has now conformed the clip to the new frame rate using the most efficient rendering method for playback performance.

I'll just click into the middle of the clip here.

There's no audio on this clip, and let's play it back.

Well, it actually looks OK.

Still, I'm going to right click on this clip and I'm going to go into the Speed/Duration... dialog box.

And this is where you can specify new playback speeds for your clips in a sequence.

What I'm particularly interested in here is the Time Interpolation option.

The default option is Frame Sampling where frames are either added or removed to give you the correct frame rate for your sequence.

Frame Blending is a more subtle approach.

It's a little bit more work for playback, it's often smoother but sometimes perhaps a little bit softer.

Both of these options are real time.

That means they'll playback without rendering, provided you have a real time system.

That's one set up with the right kind of GPU for example.

But we also have this option, Optical Flow, which is a much more advanced system for calculating frames that need to be added or removed from your footage.

Now, you'd normally use this to produce good quality slow motion from footage that was not over cranked, footage that was shot at a normal frame rate.

But this setting is also used to choose the way Premiere Pro CC will calculate frame rate mismatches between your footage and your sequence.

I'm going to turn this option on and click OK, and you can see the line along the top of the Timeline panel goes red to tell me that this needs to be rendered.

The quality is exceptional but in order for you to get the playback performance that you need, it needs to be pre-rendered.

Now, I want to take a look at some of this 96 frames per second media.

I'm going to double click to open this up in the Source monitor and you can see we've got this lovely slow motion.

And if I put this clip in our 24 frames per second sequence, it'll play fine there as well.

Let's just jump on a little.

And that's because the media is configured to playback at 24 frames per second and the sequence is also 24 frames per second.

But I don't have to have the clip playback at that frame rate.

I'm going to right click on the clip in the Project panel and go to Modify and choose Interpret Footage...

And up at the top here, we can see we can either Use Frame Rate from File, - that's the frame rate set by the camera - or we can specify a new frame rate.

Take a look at the Duration here.

I'm just going to set this to 24 fps first of all, and you can see that at 24 fps, it's about 50 seconds duration.

If I set this to 48 fps, which is still half the speed it was originally filmed at, the duration halves and that makes a lot of sense.

We're playing back at twice the speed, so we have half the duration.

I'll just click OK.

And I'll drag the Timeline over a little and you can see now the clip in the sequence has these diagonal lines to show that while the clip in the sequence still exists, it's not going to interfere with the timing of your edits.

We now only have half of the duration.

And if I play this back, it's still pretty good slow motion, but it's twice as fast as it was before.

In fact, Premiere Pro CC has still conformed this clip.

It's taken it down from 48 fps to 24 fps.

But rather than doing that by slowing down the playback of the clip, it's done it by removing unnecessary frames.

I can actually achieve the same result by taking one of these other 24 frames per second clips that were shot at 96 frames per second.

Right clicking, going into the Speed/Duration... dialogue, setting the playback Speed to 200% and clicking OK.

And now if I play this, we get a similar speed of slow motion.

So, in one case, I am telling Premiere Pro CC to playback the master clip if you like at a faster frame rate and in the other, I'm making an adjustment to the clip inside an existing sequence.

And you can easily combine those two types of setting.

So, you could start with your regular frames per second and add those clips to your sequence and then use things like time remapping or speed/duration changes to add some creative playback speed adjustments.

So that's working with mixed frame rates in Adobe Premiere Pro CC.