something about keylight

[Andrew Shanks]

Hi Max,
what problems are you having with the edges? Are they jagged? You get this if people have shot on a heavily compressed digital format like DV or HDV. There are some tricks and work-arounds for working with DV,a search of this forum will uncover all the usual techniques (usually involving softening of a colour channel before keying) but probably a good plan is to check out the free video tutorial (demo from the guys at Total Training gurus) on getting a nice DV key using keylight then applying the vector blur effect to the matte (works very well!!!)

https://www.creativecow.net/cgi-bin/page_wrapper.cgi?forumid=1&page=/articles/total_training/AE65/Vector_Blur/index.html

Keying is a pretty involved subject (I composite for film and TV, …and you will usually use more than one key, and often more than one type of keyer, to produce a final alpha to produce the final composite for a layer), and keylight is a powerful plugin with a lot of settings that all contribute to getting a good key. I suggest if you still have issues getting a good edge you maybe work through the examples in the keylight manual and also read the following articles/tutorials by Barend:

https://www.creativecow.net/cgi-bin/page_wrapper.cgi?forumid=1&page=/articles/onneweer_barend/keylight/index.html
https://www.creativecow.net/cgi-bin/page_wrapper.cgi?forumid=1&page=/articles/onneweer_barend/keyingtut/index.html

If the edge is clean (i.e. no jaggies, and the edge is correct for the edge of the object with none of the screen included) yet you have a blue tint contaminating your foreground element(which is called spill), you can tweak the colour correction within the keylight filter (indeed if you are using keylight, I’d doubt you’d have spill issues, as more often than not it over-corrects for spill), or use the After Effects Spill Suppressor filter (in the under keying in the filters menu).

Goodluck, I hope my little ramble above is useful.

Cheers,

andrew

🙂

[Max]

Thank u,really help a lot~