Zoom effect rendered as black

Hi
I am obviously missing something, but I can't figure out what.
I'm trying to recreate what's known as a 'Crash zoom' in my video - when the cameraman zooms in or out very quickly and there is blur as the shot widens.
I have set up some keyframes to automate both the 'scale' and the 'zoom effect'.
When I play the effect in FCPX it works, but when I export the movie there is just black where the effect is meant to be
What am I doing wrong?

Hi Bryan, welcome to the forum.

Have you rendered the clip on the timeline before exporting?

- Ronny

Hi Ronny.
Thanks for getting back to me.
I hadn't rendered the clip in the timeline, as I thought FC auto rendered everything in the background, and also because the effect was happening when watched in the timeline.
To be sure, I selected the clip, then Modify>Render Selection.
This took a very long time, (2hrs or so) and when it finished, the clip had a black where the frames should be in the timeline.
Perhaps the opacity had rendered that section of the clip totally transparent. I hadn't changed the opacity, it just seemed to do this.
So... now I've reloaded the clip and will try again to see if I can render it without the opacity.

I still haven't figured this out.
I added keyframes to a clip.
at the start of the clip I'm at about 150% and I zoom in to 250% at the next keyframe. I have also added a 'zoom' blur to the clip to give the effect of actual zooming in with the camera.
When I render the clip it renders the 'zoom' portion of the clip transparent. It only renders that tiny section transparent.
I would love to figure this out. It's the only thing stopping me from finishing my video.
Can anyone help?
Brian.

Hi Brian,

I just tried to do exactly the same thing as you have described and I cannot reproduce the issue.

Could you make a screenshot of your Timeline and your Viewer at the problematic spot?

- Ronny