Masking an adjustment layer

I folks. I'm quite new to FCPX but learning as fast as I can. I came across a problem today I've been unable to find a solution to, so hopefully someone on here can help. I've recorded a video which shows my iphone in the top half of the frame and a video of me in the bottom half. It's a tutorial and I want to add a vignette just to the video of me without darkening the video of my phone screen. I've added a vignette as an adjustment layer and adjusted it so that it darkens the edge around my video, but it also darkens the phone video. What I want to do is mask the adjustment layer so that it only affects the video of me. Is there any way of doing this? I've been pulling my hair out for the last couple of hours trying to find a way (and I don't have that much hair to spare). Any help on solving this would be greatly appreciated!

Dave

Welcome Dave to fcp.co

Apply the Vignette only to the lane aka 'track' showing you.
Adjustment layers affect everything below them ...

Hi Karsten and thanks for the welcome! Perhaps I wasn't clear in my description of the issue. There's only one track and it contains me and the phone with the adjustment layer adding the vignette above. It was filmed this way. I've added a couple of images which hopefully clarifies this a bit better. Apologies for any confusion.

Dave

Add a Shape Mask to the Vignette effect: in the Inspector, click the mask button and choose Shape Mask. Adjust the vignette and the mask accordingly.




And, as you go about it, why apply this to the adjustment layer? You might as well apply the effect to the clip directly.

Part of the problem it seems is that I come from a Photoshop background and I mistakenly thought layers in FCPX may work along similar lines i.e. you could mask them. Seems I may have been wrong. I got around it in the end by duplicating the track , applying the vignette to it then masking everything out except for the shot of me. That seems to work but is probably a convoluted way of doing it. Thanks - I'll bear your comment in mind about masking the effect itself for future instances where I need to do this. Your help appreciated!