Ringing effect on BG with a light
by Kenneth Crawford
on
Jul 20, 2008 at 12:14:04 am
I am working on this animation that has a dark royal blue background layer and I have a light on it to help give it a nice look and not so bland. I am using CS3 and it seems to make a ring type effect from where the light is at and its not smooth. Any reason for this and how can I fix it.
Re: Ringing effect on BG with a light by Chris Wright on Jul 20, 2008 at 12:38:02 am
because you're working with light, I thought this might be helpful.
Color Problems no more...
After Effects comes with a built in edge and halo remover for high-contrast, saturated colors. File->project settings, Linearize working space 32bpc. This works for image re-sampling, blending layers, motion blur, and anti-aliasing.
If your footage is 8-bpc, then keep working color space the same as the output color space, but I'd still recommend 32-bpc because working in 32-bpc color allows over-range colors.
The cool thing is, 32-bpc are not limited to the color boundaries of even high def footage. The over-range colors are simply a more accurate way to color correct even if you are going back to a smaller color range.
The most important thing is knowing where the final footage is going. If its for SDTV, color boundaries should be SD or you'll have illegal chroma or luma and have to use plugins to subtly soften the extremes. There's a HDTV (Rec. 709) for high def and a sRGB IEC61966-2.1 for the web, too.
Re: Ringing effect on BG with a light by Kevin Camp on Jul 20, 2008 at 1:15:39 am
even changing the comp to 16bpc will usually help.
if you want to stay in 8bpc, here's the old school way.... add a layer over the top and add the noise filter, you shouldn't need more than 5%. then adjust the blending modes for the noise layer, usually overlay or soft light works. you can tweak the opacity and noise amount as needed. adding noise seems counter intuitive, but it often works, and of course 8bpc will render quicker than 16bpc.
note that you can also add noise to an adjustment layer, but i usually feel that the noise is a little too harsh this way, but whatever works...
Re: Ringing effect on BG with a light by Chris Wright on Jul 20, 2008 at 8:09:19 am
i just thought that if you are using the light as a track matte then precompose the track and the object and in a new comp go to channel-> Remove Color Matting, that will fix the track matte halo. but if its just a regular light, well then, you have a 8 bit ugly :)
Re: Ringing effect on BG with a light by Kevin Camp on Jul 20, 2008 at 5:59:14 pm
it kind of creates a dithering-like effect to reduce the visibility of the banding that can occur with subtle gradients in 8bpc rendering.
it's not the high-end solution, but it is usually effective, and the 'dithering' is rarely noticeable after compression... as a matter of fact the dithering can sometimes improve the look of some compression, like dv25.
Re: Ringing effect on BG with a light by Kenneth Crawford on Sep 29, 2008 at 3:19:33 pm
Sorry it took me so long to reply. I tried the linerize method and that seemed to soften it but not completely get rid of it. I also tried the noise method, but I am concerned that when this is outputted, that in HD it will be noticable. Is the lights in After Effects CS3 8bit? That could be why they cause this issue.
