View Full Version : dithering - banding

10 October 2002, 06:08 PM
I have an animation that came out of MAX
a little banded but after I applied a glow or 2 to a coule layers - It looks really banded or the dithering is off or (whatever) take a look...

How could I prevent this and/or fix it.

Thanks guys,


10 October 2002, 10:14 PM
iīm not a 3d guy at all but i think the problem is the quality of your lighting?
the glow increases the banding as it makes thing brighter and applies a slightly higher contrast.
try rendering your scene again with a higher resolution applied to your light sources (sorry, i really donīt know how it is called in 3ds???)

10 October 2002, 10:20 PM
You can try rendering out to a 16bit file format rather than an 8 bit. Also avoid any type of lossy compression on your files until after you're done processing them atleast.

10 October 2002, 11:46 PM
Well unfortunately,
I've already rendered this project
but fortunately it seems to just be the ground plane thats affected so, I'm thinking that I'll rerender the ground and mask it into this.

Thanks guys,


10 October 2002, 11:57 AM
I think the Afx's glow isn't very good. I prefer to duplicate your toothbrush's layer and apply a gaussian blur effect on it, now set the opacity of this layer about 40% or 50% and try to adjust the levels of this new layer.

Often I do it to have a good glow effects. Hope this help u.:thumbsup:

10 October 2002, 06:19 PM
got one of those on there too.

10 October 2002, 03:18 PM
Sorry, I'm italian and I don't understand your slang (if it's a slang)

What do you mean whit "got one of those on there too."?

My english is not too good, sorry.

10 October 2002, 07:28 PM
"I prefer to duplicate your toothbrush's layer and apply a gaussian blur effect on it, now set the opacity of this layer about 40% or 50% and try to adjust the levels of this new layer."

what I'm saying is:
I have a layer like that also on the composition.

10 October 2002, 10:02 PM
Most of cg users use 8 bit channel graphics. Which is 8 bit each color channel. I won't do the math for you, but you can easily understand where 24bit comes from.
More infos can be easily found online about it. Along with that, you will most likely find infos about Alpha channels, 10bit files, cineon,.....

You problem about banding in AE, is a common problem with effects using only 8 bit channels.

When I started CG, I was introduced with this simple kindergarden explenation that really helped me understand the RGB values.....

One 8 bit channel = 2 exponential 8 = 256 values
256 exponential 3 channels = 16.7 million values

Now, this isn't the max you can get ! 16bit per channel has been introduced to AE in version 5.
It simply means you have more values per channel (again, more infos can me found online)
In AE some EFFECTS are available in 8bit and some are available in 16bit. (I don't know which one exactly, but gaussian blur is one of them)

So to avoid most of the banding, you should convert you composition to 16bit.
At the very bottom of the project window (the bin), there is a little box saying 8bit. Now, with ALT key pressed, click on it.
You are changing your comp to a 16bit composition.
Be carefull, the render time will be about twice slower.

Bare in mind, that if you export quicktime or tga. You will end up with a 24bit file (3x8bit). But don't worry, this is normal. It's only the output. The composition inside will be computed with 16bit per channel and will get rid off the banding.

Hope this helps.

10 October 2002, 10:03 PM
OOPS !!!
Didn't see the previous post before I submited mine.

10 October 2002, 06:08 PM
thank you very much, you're a life saver.

I actually didn't even know that...

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