Background color, alpha, and motion blur... bad combo??

[DaForce]

Da_elf:
So am I
Thanks again

egz:
Cool i will give that a try as well.
Unfortunately when you render to PNG in automatically remultiplies it anyway, but its good that you can sort that in PS
Thanks

[panthon]

If you render to PNG premultiplied with a black BG you can remove the black color in photoshop by using the layer > matting > remove black matte command.

Most of the postproduction programs let u specify if your footage has any kind of premultiply option on. Strangely enough, photoshop seems to ignore quite obvious postproduction options that can be found in after effects, being both from adobe, and u have to go with black or white matte removing...

As fas as im concerned, after effects and combustion let u specify the color u want to premultiply for, so it would be possible to render with blue background and get rid of it at the push of a button. Another option would be using a spill control filter (which is used when chroma keying), which could turn any color to another of your choice

PD: By the way, wouldn´t it be cool if we were able to keep all the filters you´ve used on each layer for further tweaking in Photoshop? I´m so used to compositing suites that gets me nervous to work this destructively