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DV Clips are “Grainy”
I captured my clips from a DV camera to FInal Cut using firewire. I noticed that the clips look a little “grainy”. They aren’t as crisp as they were on tape. Is this the compression or Quicktime? After I am finished editing the movie do I transfer back to tape to get the crispness back?
Thanks,
Paul
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8 Replies
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If they’re grainy after they’ve gone in, they’ll be grainy coming out.
It may be compression. It tends to show up more in darker footage when you’re working in DV. It’s never hugely drastic, though…
Can you post a still frame of your “graininess”?
e.
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You need to monitor the DV back through the camera to your monitor to see what it really looks like. FCP or FCE does not compress DV upon capture – it’s purely a file transfer. What you see on screen though, is preview quality only.
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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You know, Graeme, this one’s always puzzled me a bit. I know in theory it’s not recompressed, but I have seen PC DV suites using different DV codecs provide a better result than Apple DV codec.
Please enlighten me if there is something I’m missing, but it’s hard not to trust your own eyes…
And there’s also a favourite quote of mine:
“In theory there is no difference between theory and practice. In practice there is.”
:o)
e.
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Say you take in some DV over firewire, edit it cuts only, and then send it back to DV tape over firewire. Do that in any native DV editing system (FCP, Premiere, Avid, whatever) and the results will be the same, be equally good, and equally identical to the original footage.
You’ll only get differences on rendering some kind of effect, or adding text, because although the DV format says what the data has to look like, it doesn’t tell you how to achieve it.
Take chroma sampling for instance:
The Apple DV codec converts the 4:1:1 to 4:4:4 for rendering (all rendering in FCP occurs in a fully uncompressed 4:4:4 environment) by duplicating chroma samples. This looks bad on screen, but provides much better generational performance, than, say, the Avid codec. The Avid codec smooths the chroma from 4:1:1 to 4:4:4 (pretty much like adding the Apple chroma smoothing filter) and this looks nice on screen and makes for better keys, but, when compressing back to 4:1:1 for going to tape, that smoothed chroma will blur out slightly, and over many generations, you’ll get chroma bleed and desaturation.
Similarly, the Avid codec filters high frequency information from uncompressed material before rendering to the DV codec, making titles work better. This will also soften the video a bit, but it will look better on screen. The FCP codec doesn’t do this, so you get people saying that titles look bad, but if they’d filtered them themselves to the approriate level, they’d compress just fine with DV codec.
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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Cool. Well written!
Thinking back on it now, the differences I found were going in from an analog source, so, if I may, just say…. *duh*
:o)
e.
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Enzo, my article here address some of these issues:
https://www.nattress.com/Chroma_Investigation/chromasampling.htm
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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“What you see on screen though, is preview quality only.”
Once you told me that I felt better. It isn
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You’ve got to monitor DV properly, back through the deck or camera to see what it’s really like. FCP and mac monitors work in a different colour space etc., so what FCP does is just show you an approximation.
Graeme
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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