Unable to flip a clip horizontally in iMovie 10.1.6 I'm running iMovie 10.1.6 on MacOS Sierra 10.12.6 on a brand new, 2017 MacBook Air.

I have a clip which I want to flip/invert horizontally so that writing which currently appears with writing in reverse, so it is unreadable.

I've read up a lot online and everything I find says I should select the clip, click on the icon above the clip preview which is like 3 overlapping circles and then select Video Effect and choose Flipped.

However, when I click on the 3 circles icon, there is no Video Effects option shown, only Clip Filter and Audio Effect, so I don't know how to get this done.

I'm tearing my hair out at this and would really appreciate some help from anyone who can solve my problem. I know I don't have much rep here - I wish I could put a big bounty on this question because it's driving me nuts!
If I understand your question correctly, you can do what you want as follows:


Select the clip
Click on the icon you called the 3 overlapping circles
Click on the Clip Filter option
In the Choose Clip Filter window that appears, select the Flipped filter
This will now film your clip horizontally


I've created a visual diagram of steps 2 - 4  below: