Fcpx custom speed imperfection

[soren k jensen]

So I shot 6k red raw at 75 fps on a 25 fps timebase, to be able to use both normal speed and slow motion. 'Normal' speed at 100 percent gets me smooth 3x slow motion. But when I use 'custom' speed, Fcpx will not allow precisely 300%, but adds a digit or two, so it becomes e.g. 300,07%. Why is this, and is there a solution?

 

[Alan Greene]

It may be due to the number of frames in the clip. For example, if the clip is exactly 75 frames long, then 300% speed yields exactly 25 frames in the timeline. However, if the clip is 76 frames long, 300% speed would yield 25.333 frames in the timeline, which is not possible. So the actual adjusted speed is 304% (76 ÷ 25), and FCP will display it as such. I've seen the same thing, and that's my guess.