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Is Betacam sp 3:1:1 or 4:2:2?
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Nicely put Charlie. I share your sentiments.
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Is BetaSP so far gone that people don’t even understand the not-so-distant analog world?
I don’t have my PVW series decks anymore, but it’s always pleasant to turn on my UVW-1800 and it says, “Welcome to: Betacam SP” Makes me smile.
As for the postings here I, too have never heard of 3:1:1 and I’m very confused as to why Beta SP would be described in digital sampling terms. That’s like making apple juice with oranges.
The correct way to put things would be to say that 4:2:2 is more like BetaSP’s analog color bandwidth than DV’s 4:1:1 or 4:2:0.
Jon
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Amen brother Jonathan
Charlie
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i think adam wilt was saying that beta cam sp produces an image that for the sake of comparison only, that though it’s analog, were it digital, it would be roughly equivalent (note the qualifier “would be”) to a digital image sampled at 3:1:1.
I got confused when one of our camera operators began insisting that betacam was 4:2:2. he backed his argument up with some highly technical gobbledigook. i think i should fire the camera operator. i came here for clarification.
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OK, Digi-beta is 4:2:2 at a 3:1 or sometimes referred to as 2.5:1 compression ratio.
Betacam SP is analog, the color you see is the color you get. One difference you may notice in betacam is it will have some noise in the picture. When that picture is transferred to Digital, it is actually compressed and in the compression scheme the first thing to go is the noise which will give the impression of being cleaner than the analog Betacam.
I believe it is this perception that they may be talking about instead of the actual video quality, or colorimitry.I hope this helps in your understanding. I apologize if I seemed coy or unhelpful. I just find it difficult at times to understand how a degree seems to make people more knowledgeable when my experience has seen many degrees that couldn’t make it in the real world so they returned to a major university to teach. I don’t mean any disrespect for anyone, cause I have also seen many degrees that hit the real world with a quest for learning more and those people have gone far, unlike the ones that taunt the degree as symbol that they know everything and are ready to conquer the world of TV, or movies.
Charlie
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maybe the following article is helpful:
https://www.nattress.com/Chroma_Investigation/chromasampling.htm
Graeme Nattress compares DV and betaSP and digibeta in terms of color and luma resolution.
DV has slightly better luma resolution than betaSP, and slightly worse color resolution.As others pointed out, betaSP is not a digital format so it’s not really 3:1:1 or 4:2:2.
Typically you want to capture betaSP digitally with 4:2:2 color sampling to get the most out of it. -
After reading the article, I see where it is ery difficult to get really fair comparisons in some areas. For example, starting with Digital Betaca footage, the dubs were made by SDI to the digital formats.
The dub to and from the Betaca SP would have had to be made through the analog output of the Digital Beta, then an analog output from the Beta SP. This in essence has give the eta SP a disadantage from the onset of making the video 2 generations of analog to the final destination. Since analog has losses in generational output. You are not starting with a first generation as you in essence have from the digital sources.Just a simple observation that makes these types of comparisons a little less than perfect.
Charlie
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One more thing to consider…
4:2:2, 4:1:1 and 3:1:1 are all ratios. We know that SMPTE 259M (ITU-R 601) and DigiBeta are 4:2:2.
DVCPRO is 4:1:1
Would not 3:1:1 be some sort of guessed-upon tip-of-the-hat to BetacamSP? The ratio actually would seem to indicate a greater amount of chroma sampling to luminance than your run-of-the-mill DVCPRO 4:1:1.
Where I work, we are still in a hybrid Digital-Analog world with BetaSP and DVCPRO. It’s a real toss-up. We like the resilience of DVC to tape dropouts, but we like the resulting picture of a BetaSP better. It’s also much easier to pull a greenscreen matte from a BetaSP master than a DVCPRO. (Thus would indicate a smaller ratio of Chroma to Luminance sampling)
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3:1:1 is something adam wilt made up to approximate betaSP sampling to the color sampling digital formats. Graeme’s article indicates that betaSP is probably something more like 3.something:1.something:1.something.
Anyways, it may not be too useful to characterize betaSP as 3.something:1.something:1.something.
2- Scott, have you tried applying chroma interpolation or chroma smoothing to the signal from DVCPRO? I believe DVCPRO decks with SDI out do this.
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