widescreen bars look shaking

Hello, I am doing a music video where I want to put a widescreen effect on it but for some reason the top bar looks shaking, is there something I can do to prevent this. Thanks

What tool are you using to implement the widescreen letterbox?

Ok first of all excuse my lack of knowledge , I am kind of new on FCP, but basically what I am doing is going to the broswer found the widescreen effect and drag it to the clip on the timeline I don't know if this the right thing to do, thanks for any help.

Yeah, that filter creates some jitter. I usually create a new solid (matte) make the color black, then add the "matte shape" filter. Take the horizontal scale to 100% and adjust the vertical scale to taste.

Some people also create a PSD with black bars in photoshop for the different aspect ratios.

Or, nest the sequence when it's done and crop the top and bottom. Using a matte gives far more versatility when working, though.