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Nattress Chroma Sharpen problem
Hi all,
Shooting rock concert I got my footage with a lot of chroma artifacts (red stripes all over the red edges). I was recommended to try Nattress’ “G Chroma Sharpen” plugin. At the beginning i was really surprised how it helps and restorring my footage. When i am applying filter on video then in the viewer i can see preview of the effect and it was realy great (almost unbeleivable)! All red garbage is gone and picture looks like from HD!
But…
… when i render or save video to the file, then i get back to the problem of red stripes all over the footage. it is like filter DID NOTHING. I was compiring original footage and filtered and it is exactly same.
In the canvas you always can see frame by frame preview of the filter even if it is not rendered yet. And also i can see the result of chroma sharpen filter and it is great. But when i start to render and then cancel it, then i get part of the timeline rendered (grey marking) and rest is not rendered (red marking line on top of the timeline). when i go frame by frame again then in the rendered part it is awful again and unrendered is looks realy nice.
I was trying all the possible combinations of settings (progressive and interlaced, 4.2.0 and all other) but problem just the same.
Please help me to understand what i am doing wrong.
thank you, Andrew -
10 Replies
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[Andrew B.] “But…
… when i render or save video to the file, then i get back to the problem of red stripes all over the footage. it is like filter DID NOTHING. I was compiring original footage and filtered and it is exactly same.”
Have you actually purchased the filter or are you trying it out?
Walter Biscardi, Jr.
https://www.biscardicreative.com
HD Editorial & Animation for Food Network’s “Good Eats”
HD Editorial for “Assignment Earth”“I reject your reality and substitute my own!” – Adam Savage, Mythbusters
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Do you have any other filters applied to the clips? I’ve noticed when using Nattress that sometimes the effect may change/look different depending on what order it’s in in the filters tab.
Andrew
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I’m guessing you’re fixing DV chroma artifacts? Then what you’re seeing is correct! That’s because as soon asyou render back to the DV codec, the DV codec undoes all the good work the filter did!
So, what do you do – well, you’ve got to render in an uncompressed or 4:2:2 or 4:4:4 timeline to see the effect and to keep it after render. Basically, DV is 4:1:1 chroma sampling. This means that the full resolution of the chroma is reduced to 1/4 by the codec. Fixing that with the chroma sharpen, you see the effect because FCP renders in 4:4:4, but once it goes back to the DV codec, it throws away all that lovely chroma information, taking you back to the 4:1:1 you started with.
Hope that helps,
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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[walter biscardi] “Have you actually purchased the filter or are you trying it out?”
I did not buy the filter yet but trying demo version from the Nattress’ site.
[Andrew Schuurmann] “Do you have any other filters applied to the clips? I’ve noticed when using Nattress that sometimes the effect may change/look different depending on what order it’s in in the filters tab.”
i do not have any other filter applied to the clip. after i met the problem i made new fresh sequence and, to be sure, experrimenting with only one filter applied .
[Graeme Nattress] “I’m guessing you’re fixing DV chroma artifacts?”
Yes, it is DV chroma artifacts and i beleive it is exactly the problem you pointing me now. Thank you Graeme for your kind help. I will give it try and let you know about my success.
thank you all for your kind responce,
Andrew -
Andrew, looks like you’re on the right path now – do tell us how you get on.
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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So, that was exactli the problem that i was trying to apply Chroma Sharpen plugin to the clip on 4:2:0 timeline. As Graeme explained, it shows correct collors as preview but when i rendered it to DV codec, then problem comes back again.
Now I did DVCPRO50 timeline and drop my clip on it and used Nattress’ Chroma Sharpen plugin with success! Thank you, Graeme!
Now I see other problem that actually i can’t use it because final format for the video project is going to be DVD, which has 4:2:0 sampling too and all my corrections will be back again and it means no need to correct collors at all.
Am I right?
What could be the sollution is somehow reduce red collor. I do not know how to do it properly. Any tip will be appreciated.
Thank you,
Andrew -
4:2:0 Timeline? Is this PAL DV, if so, there’s not much you can do as PAL DV is 4:2:0 as is DVD. In the NTSC world, 4:1:1 from NTSC DV doesn’t translate to 4:2:0 of DVD very well, but if you fix the chroma first, it translates a whole lot better!
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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[Graeme Nattress] “4:2:0 Timeline? Is this PAL DV, if so, there’s not much you can do as PAL DV is 4:2:0 as is DVD.”
yes, i was shooting PAL. Is there any help to restore chroma if i will have to put final movie to DVD?
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Not really. Problem is both PAL DV and DVD are similarly chroma limited. No way around that.
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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Graeme, thank you very much for your kind help. I hope one day i will use your great plugins on my projects.
Andrew
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