Optical Flares Compression Problems

[Chris Brett]

Hi —-
— there are always restrictions to what you can display on any system however most of these do not matter because the result looks more than good enough to the human eye.

Therefore if one uses compressed formats, low bpc or formats that have poor resolution for the display size then banding can result in areas which require more ‘pixel information ‘such as the one you describe.

In my experience this is often impossible to completely eliminate and I am quick to adjust the edit in some way to improve the look if at all possible.

Sometimes I just reduce it as much as possible and send it to the client and in case its any consolation I’ve never have a job refused because of this – non video people are not as sensitive to it as us guys I think…

— However things you can try are :

1 ) better compression codecs ( not my area so best not to advise here )
2 ) use grain / anti banding tools – I know you have tried this but sometimes small adjustments to the spark setting can make quite a difference — its worth tweaking the settings a bit before you give up
3 ) use more colour / contrast in the area affected – this gives the spark greater range to play with when it calcultes the changes from A to B and this can reduce the noticeability of any banding.

My guess is that for Youtube and looking at your uploads ( which do not show any banding BTW ) a combination of 1 and 2 is best – codecs can make a BIG difference…

———— all the best ——chris —

[Chris Wright]

i would simply import a rendered low chroma output back in(make sure it’s a 4:0:0 or 4:2:0 but at highest quality.)

and then use denoise or neatvideo to fix the final product. It’s alot easier than guessing what’s going to work before you render, believe me, because the last thing you want to do is compromise your vision by removing effects.

AE usually dithers 32bpc to 8bit but it is notorious for not supporting chroma downsampling. It’s been 20 years, come on, adobe!

[Walter Soyka]

On the topic of debanding, I’m a big fan of GenArts Sapphire S_Deband.

If you’re on a Mac, you could look into PHYX Cleaner Deband (via FxFactory).

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Walter Soyka]

[Chris Wright] “i would simply import a rendered low chroma output back in(make sure it’s a 4:0:0 or 4:2:0 but at highest quality.)… AE usually dithers 32bpc to 8bit but it is notorious for not supporting chroma downsampling.”

Chris, having seen some of the devilishly genius AEPs you’ve published, I’m a little surprised you haven’t whipped one up one for chroma subsampling with Channel Combiner, Set Channels and Mosaic. It’d be 8b, but still…

There’s also Christian Lett’s qp_ChromaSubsample effect [link], but since it’s based on PixelBender, it’s not compatible with CS6.

[Chris Wright] “It’s been 20 years, come on, adobe!”

Tell them here:
https://www.adobe.com/cfusion/mmform/index.cfm?name=wishform

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog – What I’m thinking when my workstation’s thinking
Creative Cow Forum Host: Live & Stage Events

[Chris Wright]

this also might help

if you add an adjustment layer – mode color
add effect median around 5
it will blur the chroma and not the luma. might help the compression. also, make sure you don’t use any 8 bit effects, little yellow triangles will disable 32bpc processing.