View Full Version : Compositing Problem - White Fuzzy Edges

02-15-2004, 09:23 PM
This problems been bugging me for awhile now.

When I save images as 32-tiff or 32-PNG files, for the purpose of compositing stills in Photoshop. I end up with these white fuzzy edges. Is there something I'm doing wrong or any solution to avoid this problem.

It's most noticeable when the image is placed on a black background.


02-15-2004, 10:49 PM
I can guess that you rendered over white, then try to comp. over black. The antialiasing in the render mixes the bkg color into the object to smooth it. You need either to render against the same bkg color you are comping with, or use "Fader Alpha" mode in LW to render un-premultiplied RGB and Alpha.

02-16-2004, 02:12 AM
Thanks RUdiger that worked perfect first time.

02-17-2004, 06:35 PM
You guys mentioned a 'fader alpha' mode. I've been trying to figure out how to save an animation as an alpha channel. I had to animate a bowel system for an educational film and I'm supposed to put it over an actor in after effects, but I can't figure out how to render the background as transparent. If you have any ideas, please let me know.
Have a good one!

02-17-2004, 06:43 PM
Never-Ever render out as an animation, always render out as a series of images, in this case something like 32bit png or tifs, then when you import the image sequence the background should be transparent.

02-18-2004, 09:27 AM
to answer the 1st question, after effects can deal ok with both types of alpha for example (premiere pro can't - in my experience).

<ot>i just got my job version of lw 7.5, huray! :D </ot>