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Composite VS Component


davide sorasio
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I'll bite. Both carry a similar signal - the primary difference is that component can produce a better quality picture because it carries the image over 3 cables instead of 1 in composite. When you mash the color and luminescence values together into one cable, you'll loose picture quality.

Edited by Landon D. Parks
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The luminance is the base signal, it's the "Y" cable of your composite system. With composite, the luminance gets a compressed chrominance subcarrier frequency attached to it. The color carrier is generally half of the scanning rate, this is why composite doesn't doesn't look nearly as good as component.

 

Composite was designed specifically for broadcast and almost all of the standard definition systems and video tape machines made, were based on a composite standard.

 

Component signal separates the luminance from chrominance. There are three ways to do this, one is carry the chrominance signal combined, which is S-Video. Another is to separate the Blue and Red signals which is what we refer to as YPbPr, which has 3 black and white signals which carry the chrominance in them. The final way is true RGB, which of course is one cable carrying Red, Green, Blue signal.

 

The most common NTSC/Consumer component signals are S-Video and YPbPr. RGB wasn't as widely used in broadcasting because most equipment was composite until the innovation of digital technology. When Serial Digital Interface (SDI) came around, most broadcasters switched over and analog as we know it, died on the vine very quickly.

 

As a side note, there were only two component analog tape formats; Betacam SP and it's Panasonic rival MKII.Both recorded component signal on to tape, exactly how it went into the machines with no muxing. So almost all of the other tape formats were composite. Some machines came with an S-Video output, but it was only on the higher resolution ones; LaserDisc, Hi-8, S-Video and Betamax Hi-Band.

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The luminance is the base signal, it's the "Y" cable of your composite system. With composite, the luminance gets a compressed chrominance subcarrier frequency attached to it. The color carrier is generally half of the scanning rate, this is why composite doesn't doesn't look nearly as good as component.

 

Composite was designed specifically for broadcast and almost all of the standard definition systems and video tape machines made, were based on a composite standard.

 

Component signal separates the luminance from chrominance. There are three ways to do this, one is carry the chrominance signal combined, which is S-Video. Another is to separate the Blue and Red signals which is what we refer to as YPbPr, which has 3 black and white signals which carry the chrominance in them. The final way is true RGB, which of course is one cable carrying Red, Green, Blue signal.

 

The most common NTSC/Consumer component signals are S-Video and YPbPr. RGB wasn't as widely used in broadcasting because most equipment was composite until the innovation of digital technology. When Serial Digital Interface (SDI) came around, most broadcasters switched over and analog as we know it, died on the vine very quickly.

 

As a side note, there were only two component analog tape formats; Betacam SP and it's Panasonic rival MKII.Both recorded component signal on to tape, exactly how it went into the machines with no muxing. So almost all of the other tape formats were composite. Some machines came with an S-Video output, but it was only on the higher resolution ones; LaserDisc, Hi-8, S-Video and Betamax Hi-Band.

Thank you so much, this is really useful information. My further question related to the topic comes from an experience I had on set last week. We were shooting on the Arricam Studio, so in order to have a working TV logic we had to use an RCA adapter to convert the HDSDI into an "analog signal". We got the adapter and were able to get a (really low quality) image on the TV logic by switching the input of the tv logic to composite and plugging the connector into the Luma input of the TV Logic. My question is, in order to get a better image for the AC on the TV logic would have been ipotetically possible to switch the TV logic input to component and use 3 different BNCs, each one going into the 3 different Green,Red, Blue inputs? Would that have made possible getting an image usable to pull focus on the TV logic?

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Thank you so much, this is really useful information. My further question related to the topic comes from an experience I had on set last week. We were shooting on the Arricam Studio, so in order to have a working TV logic we had to use an RCA adapter to convert the HDSDI into an "analog signal". We got the adapter and were able to get a (really low quality) image on the TV logic by switching the input of the tv logic to composite and plugging the connector into the Luma input of the TV Logic. My question is, in order to get a better image for the AC on the TV logic would have been ipotetically possible to switch the TV logic input to component and use 3 different BNCs, each one going into the 3 different Green,Red, Blue inputs? Would that have made possible getting an image usable to pull focus on the TV logic?

I've got an old sdi-analog converter box. It can output composite or component I believe, but I've never used the component as the SD analog is so bad compared to the HD SDI signal. For focus pulling, SD is not going to cut it anyways, so I wouldn't worry about composite signals to a little SD monitor.

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Already answered in your other thread, but when shooting film you are making a big mistake by letting your AC pull focus from the monitor. There is simply not enough resolution there, especially when you consider how large the final image will be and thus how small your circle of confusion actually is. The AC must pull focus by marks and distance, end of story. The monitor is only for checking framing and metadata if there is any.

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Component signal separates the luminance from chrominance. There are three ways to do this, one is carry the chrominance signal combined, which is S-Video. Another is to separate the Blue and Red signals which is what we refer to as YPbPr, which has 3 black and white signals which carry the chrominance in them. The final way is true RGB, which of course is one cable carrying Red, Green, Blue signal.

 

Everything is pretty clear until this point. My last doubt comes from S-Video. In this case how many cables are used? Is it one with the luminance and then the chrominance combined?

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Davide, there are whole Wikipedia entries on these things, why don't you spend a little time looking this stuff up before you start asking for clarification here?

 

See:

https://en.wikipedia.org/wiki/S-Video

I did. I do not completely trust wikipedia (it happened to me to read something and then finding here from other people that wikipedia was wrong). I trust more the experience of people here. To be honest I do not wanna learn something that is wrong and that is going to make me look like a fool. And for the last part of the topic in fact I feel like I'm asking for confirmation to see if I elaborated the info in the proper way. For example, about my last question about YPrPb wiki doesn't tell if it requires 3 diff cables or if that is a "y" cable with 3 different ends.

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I don't see why a forum poster is necessarily more reliable, you have to gather information from a variety of sources and look for confirmation, but basic stuff like what is component video and composite video is well-defined in hundreds of technical manuals and websites, so I don't see why someone here, unless they look stuff up first to confirm their facts as I often do -- and thus doing homework for a person who was too lazy to do that homework themselves -- is more accurate by default.

 

Asking people to define basic technical terms that you could look up yourself is no better than asking people what the capital of some country is, or who shot what movie, etc. If we are going to put in time and effort to answer questions on this site, we expect the original posters to do the same effort in looking stuff up.

 

If you need clarification or confirmation on some fact you found elsewhere, then just say so up front. If you looked up component and composite video and found some fact confusing or contradictory, then go ahead and ask. But don't show up on a forum and ask people to define basic terms. Why not ask "what's a lens?" "What is reversal film?" "What is an SSD?" Asking what the difference is between component and composite video is the same type of question. Unless you simply didn't understand what you read and need it explained to you more clearly and simply.

 

This is just one of my pet peeves and it goes back 18 years or more of answering questions online. Someone would ask for a definition, so I'd look it up on several sites just to confirm what I thought I already knew, and then I'd compile all that information into a forum post, sometimes citing sources... doing work that the original poster could have done.

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I don't see why a forum poster is necessarily more reliable, you have to gather information from a variety of sources and look for confirmation, but basic stuff like what is component video and composite video is well-defined in hundreds of technical manuals and websites, so I don't see why someone here, unless they look stuff up first to confirm their facts as I often do -- and thus doing homework for a person who was too lazy to do that homework themselves -- is more accurate by default.

 

Asking people to define basic technical terms that you could look up yourself is no better than asking people what the capital of some country is, or who shot what movie, etc. If we are going to put in time and effort to answer questions on this site, we expect the original posters to do the same effort in looking stuff up.

 

If you need clarification or confirmation on some fact you found elsewhere, then just say so up front. If you looked up component and composite video and found some fact confusing or contradictory, then go ahead and ask. But don't show up on a forum and ask people to define basic terms. Why not ask "what's a lens?" "What is reversal film?" "What is an SSD?" Asking what the difference is between component and composite video is the same type of question. Unless you simply didn't understand what you read and need it explained to you more clearly and simply.

 

This is just one of my pet peeves and it goes back 18 years or more of answering questions online. Someone would ask for a definition, so I'd look it up on several sites just to confirm what I thought I already knew, and then I'd compile all that information into a forum post, sometimes citing sources... doing work that the original poster could have done.

I understand your point, and I apologize if this bothered or annoyed anybody else. I really appreciate the info I was able to get from this forum and all the people in it, especially from you David. I'll pay more attention in the future to go more in depth before asking something.

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Thanks. And I'm glad you are questioning things you read on Wikipedia, but I think for most mundane technical definitions (like what is 4:2:2 or what is 8-bit, etc.), it is a fairly good jumping off point. Internet discussion forums are also useful, but more of actual hands-on personal experience or for clarification of technical information.

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Contrary to some peoples opinion (especially in the academic world), I find Wikipedia to be pretty truthful. The only area where one might want to take caution is in articles about people, which can sometimes be less than fact driven. Most technical articles on Wikipedia are written by people who know what they are doing, and vandalism outside of hot topics like famous people, certain world events, and politics is fairly rare. I may be biased since I'm a contributor myself, and partake in policing new articles by less than established editors.

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