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chroma key
Hi. I have imported a photo into FCP of a white painted roundish rim (like a ring) which I want to isolate from it’s background (bright blue) in order to superimpose onto clips. I have been able to do this with chroma key except the outer edges of the rim are feathered and I’m finding it hard to make all the blue drop away in the feathered section. The pixels appear more evident in this area also. Do you have any advice? Also what would be the optimum resolution for imported photos? Thanks, Jenny
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1 Reply
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Hi, Jennifer.
This is how I would do it.
Go back into Photoshop with your ring picture. The picture should be saved in a better quality format than jpeg, and in a decent size; 720 x 486 pixels or larger (you can always shrink a too-large graphic later, but enlarging a too-small one gives you fuzzy quality)
Save as tif, tga png or psd. Myself, I like targa. Any of those formats can preserve alpha channel information in layers.
Save the graphic in photoshop and go to layers>add layer. Leave this new layer blank and put it in the bottom of the stack in the layers palette. If the original layer is locked (little padlock icon) double-click it to open it, okay it, then it should be unlocked and now you can drag it to a higher layer in th stack so it’s ring layer then blank base layer.
Use photoshop’s selection tools and perhaps the select by color option to isolate your ring, then when the non-ring parts are selected with the crawling ants marquee tool, feather the selection under the “select” drop-downj menue. try to shrink it by one pixel and feather it by 2-3 pixels. Now while the slection is still going with the marching ants, go to edit>cut. Save the result with a new name and make sure it retains the layers when it asks you. Import that into final cut and lay it on the timeline above your main footage track and no worries about chromakeying. You are ALPHA keying now.
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