Trying to understand how FCP X handles 60p footage in 24p timeline

I have a 24p timeline and I'm importing a 60p shot into it. It plays just fine and I can easily re-time it to 40% to achieve a 2.5x slo mo. Is this the best way to do that in FCP X? I read that fcp users converted via cinema tools earlier and had to apply a few settings to make sure that the footage wasn't imported with dropped frames.

My question is - how does fcp x handle imported 60p footage? Does it skip frames to make it fit the 24 p timeline - and then how does it slow it down to 40% - does it re-import the dropped frames or does it interpolate the 24p footage?

Thanks in advance, I can find plenty of information that primarily tells you how to do this but not what fcp x actually does or whether it's the best way to make slo mo footage using 60p and 24p footage.

If you want to slow down the 60p media, in the retime menu use the conform function.

You're right - it's super easy and seems to work well.

Actually, isn't it already being converted to 24p when you drop it on the timeline? And when retimed, does it actually pull in lost frames?

But how does it actually work - do you know what I mean, I'm wondering if I'm really making the most of my 60p footage or if it's just being converted 2 ways (first to fit the time line and 2nd to play in slo mo).

When the 60p media is put in the 24p project, frames are tossed so the speed of the clips remain the same. When you conform the frames are put back in and played one frame of 60p for one frame of 24p project; the result is slomo.

FCPX does an excellent job of handling this by the way.

Thx Tom! I was always wondering what was going on behind the scenes. Do you have a source?

Cnema Tools is built into FCPX. And the "old way" with cinema tools was destructive.
Therefore FCPX handles this much better and easier. You can choose if you want "normal speed" or the slow motion.

I shoot a lot overcranked and/or 720p50 actually and there is a keyboard shortcut "Conform Speed" which speeds this up even more.

Actually, to be technically curate, Cinema Tools was tossed. A "conform" function was written from scratch for use in FCP X. The original Cinema Tools did much more than just conform frame rates, and it was non-destructive as it worked off of a database, never altering your original media.

One thing it did most folks overlooked was made lists of used media in your Sequences, for comparison to your full list of media in the Browser. Something that needs to be written in to FCP X (y'all fill out that Feedback form!).

For me it was alyway destructive to conform speed in Cinema Tools.
I know CT did much more than just conform, but that was what I used it for (after making a copy of every 720p50 shot)

It must be rewritten...it uses all cylinders of my machine