So Harry asked me to write him a Neutral Density Gradient filter and whilst it certainly seemed doable I wasn’t especially inclined, so I attempted to post back that it was easy enough to do using the built-in Custom Gradient filter (in the Effects > Video Generators > Render bin) applying that to the layer above the problem clip and changing the Composite Mode ought to do the job.  Trouble was that Apple’s FCP discussions forum was playing hard to get ... nothing on the telly, not tired enough for bed, finished my book already, and now the the forum down as well. Ok, what the heck, a challenge is a challenge right?

This is the result...  Andy's Gradient Filter.zip.  Anyway, Harry was pleased, and I’m hoping you’ll find it useful too.

By the way, what are you doing on Saturday week?  Harry and I are getting hitched...