4:4:2 (4:2:2??)

Matt Watkinson · July 4th, 2005, 01:01 PM

Hi there.
I'm about to head out to Tokyo to start work there, which happens to coincide with some documentary makers I know needing somebody to shoot a couple of brief interviews in the very same city. They asked me to do it and trained me in how they'd like it shot, so no concerns there. They even said that they'd half pay for a new camera (which is great, as I was intending to get one anyway). However, I forgot to confirm one thing, and the people I'm helping wil be out of contact somewhere in S. America until I leave the country (and I'd like to get the camera before I do this, ideally).
So anyway, what I forgot to check has to do with getting a camera that can provide images of sufficient quality. I'm not asking for recommendations - browsing the forums and other sites there's ample info on that kind of thing - but rather how to determine whether a certain camera has a certain feature. I was told that the camera I get needs to be able to produce images of broadcast quality, which was defined as either 4:4:2 (I think) or 4:2:2 (could have been this as well...) output. I took the time to read some technical article and am aware of what this means, but what I don't know is how to determine which cameras can do this. It doesn't appear in any of the spec sheets that I've read. If anyone can tell me how to find out whether a camera can produce this output I'd be extremely grateful!
I suppose it might be a good idea to ask, while I'm at it, if there's any likelihood of a camera with said output overlapping with the type of camera that I was looking to buy myself (probably a mid-range consumer cam, price would be about $600-800, certainly nothing leaning towards the cool end like the Canon XL2 or whatever). I'm sorry if these questions have glaringly obvious answers, but as I noted in the title, I really am a novice, and what's worse, a novice who failed to ask the right questions when he had the people with knowledge around!

Graeme Nattress · July 4th, 2005, 01:06 PM

http://www.nattress.com/Chroma_Inves...masampling.htm

Will tell you all about chroma sampling. For a standard definition camera, the only models that have 4:2:2 chroma sampling are those that shoot in the DVCpro50 or Digital Betacam formats, and they are not cheap. All DV cameras (if NTSC) shoot 4:1:1.

Graeme

Steven White · July 4th, 2005, 02:04 PM

Graeme - I have a question on your 4:2:0 illustration.

Is it really a line of Cr followed by a line of Cb, or do they alternate across the line?

i.e.:
Cb Cb Cb Cb Cb
Cr Cr Cr Cr Cr

vs.

Cb Cr Cb Cr Cb
Cr Cb Cr Cb Cr

Of course, I wouldn't be surprised if it could be either... but I wonder which is more common.

-Steve

Graeme Nattress · July 4th, 2005, 02:11 PM

As far as I know, the diagram is accurate to how 4:2:0 works, with a line of Cb followed by a line of Cr. This is fine in progressive, but in interlace, each field has a line of Cb followed by a line of Cr, and that's messy indeed.

Graeme

Dan Mumford · July 5th, 2005, 09:08 AM

Matt,

I have a couple of questions. You said they trained you to shoot the interview, but I'd like to know how they trained you. Did they show you how to use a particular camera? If so, do you remember the make and model?

When they offered to pay half of the camera's price, do they expect you to pay for it then reimburse you, or are they paying half up front? Did they give you an amount they were willing to pay for the camera?

I ask these questions because it seems a little funny that they would offer to pay a novice to do a job that would be a lot easier and cheaper if they just found someone that already has the experience and equipment. They should know that a camera with the 4:2:2 specs will cost well over $10,000.00. That's a lot to pay for a couple of interviews, even paying half. Then you have the extra equipment; mics, lighting, cables, etc.

You can get acceptable broadcast quality from lesser cameras such as the GL2, XL2, or some of the higher end Sony, JVC, or Panasonic cameras.

Just a little food for thought. I would hate to see you go into debt for all this equipment and not get paid what you thought you deserved.

Dan

Matt Watkinson · July 6th, 2005, 07:03 AM

Thanks for the advice. I appreciate the concern, but having read around a bit it seems likely that the real problem is that the documentary makers don't know too much about the technical side of things - while I didn't provide any details in my first post, they are barely more experienced than I am (although there has clearly been some confusion over the kind of camera I need - they would never have expected me to get anything that pricey). The main reason that they wanted me to do it is that I have specialist knowledge of the field that they're investigating and can speak pretty decent Japanese (and English, although hopefully that's apparent from my writing...). On reflection it's most likely a task that's technically beyond me. Probably the best thing to do would be to investigate hiring people with the correct knowledge and equipment, and I can just do the talking! I am, however, pretty confident that it's more a case of crossed wires than anything. I've known these guys for 10 years or so and have complete faith in them. Just have to wait for them to come back from their holiday...

Matt Watkinson · July 6th, 2005, 07:10 AM

Also, just for my personal interest:
The article that Graeme kindly linked to, while quite difficult reading for someone unfamiliar with the subject, was most illuminating. It seems to suggest that you can 'upsample' other types of footage into 4:2:2 quality using software routines. Is this the case? Of course, I understand that any post-shooting process is not going to be able to suddenly add new data to the image that was not there before, but presumably it would make the footage 'compatible' with other 4:2:2 stuff (ie could be edited into the same footage). As I'm not actually going to have to film anything that's high speed/high colour/complicated in any way but rather just a guy sitting there and talking, the difference might not be so notable...maybe?? I think I'm a little out of my depth! Still, it's interesting to learn about it.

July 4th, 2005, 01:01 PM	#1
Matt Watkinson Tourist Join Date: Jun 2005 Posts: 3	4:4:2 (4:2:2??) - novice question Hi there. I'm about to head out to Tokyo to start work there, which happens to coincide with some documentary makers I know needing somebody to shoot a couple of brief interviews in the very same city. They asked me to do it and trained me in how they'd like it shot, so no concerns there. They even said that they'd half pay for a new camera (which is great, as I was intending to get one anyway). However, I forgot to confirm one thing, and the people I'm helping wil be out of contact somewhere in S. America until I leave the country (and I'd like to get the camera before I do this, ideally). So anyway, what I forgot to check has to do with getting a camera that can provide images of sufficient quality. I'm not asking for recommendations - browsing the forums and other sites there's ample info on that kind of thing - but rather how to determine whether a certain camera has a certain feature. I was told that the camera I get needs to be able to produce images of broadcast quality, which was defined as either 4:4:2 (I think) or 4:2:2 (could have been this as well...) output. I took the time to read some technical article and am aware of what this means, but what I don't know is how to determine which cameras can do this. It doesn't appear in any of the spec sheets that I've read. If anyone can tell me how to find out whether a camera can produce this output I'd be extremely grateful! I suppose it might be a good idea to ask, while I'm at it, if there's any likelihood of a camera with said output overlapping with the type of camera that I was looking to buy myself (probably a mid-range consumer cam, price would be about $600-800, certainly nothing leaning towards the cool end like the Canon XL2 or whatever). I'm sorry if these questions have glaringly obvious answers, but as I noted in the title, I really am a novice, and what's worse, a novice who failed to ask the right questions when he had the people with knowledge around!

July 4th, 2005, 01:06 PM	#2
Graeme Nattress RED Problem Solver Join Date: Sep 2003 Location: Ottawa, Canada Posts: 1,365	http://www.nattress.com/Chroma_Inves...masampling.htm Will tell you all about chroma sampling. For a standard definition camera, the only models that have 4:2:2 chroma sampling are those that shoot in the DVCpro50 or Digital Betacam formats, and they are not cheap. All DV cameras (if NTSC) shoot 4:1:1. Graeme __________________ www.nattress.com - filters for FCP

July 4th, 2005, 02:11 PM	#4
Graeme Nattress RED Problem Solver Join Date: Sep 2003 Location: Ottawa, Canada Posts: 1,365	As far as I know, the diagram is accurate to how 4:2:0 works, with a line of Cb followed by a line of Cr. This is fine in progressive, but in interlace, each field has a line of Cb followed by a line of Cr, and that's messy indeed. Graeme __________________ www.nattress.com - filters for FCP

July 5th, 2005, 09:08 AM	#5
Dan Mumford Regular Crew Join Date: Feb 2005 Location: Daytona Beach, Florida Posts: 99	Matt, I have a couple of questions. You said they trained you to shoot the interview, but I'd like to know how they trained you. Did they show you how to use a particular camera? If so, do you remember the make and model? When they offered to pay half of the camera's price, do they expect you to pay for it then reimburse you, or are they paying half up front? Did they give you an amount they were willing to pay for the camera? I ask these questions because it seems a little funny that they would offer to pay a novice to do a job that would be a lot easier and cheaper if they just found someone that already has the experience and equipment. They should know that a camera with the 4:2:2 specs will cost well over $10,000.00. That's a lot to pay for a couple of interviews, even paying half. Then you have the extra equipment; mics, lighting, cables, etc. You can get acceptable broadcast quality from lesser cameras such as the GL2, XL2, or some of the higher end Sony, JVC, or Panasonic cameras. Just a little food for thought. I would hate to see you go into debt for all this equipment and not get paid what you thought you deserved. Dan __________________ Wow! That thing must have cost an arm and a leg! - - - It did! I used to have three of each.

July 4th, 2005, 02:04 PM	#3
Steven White Major Player Join Date: Nov 2004 Location: Canada Posts: 547	Graeme - I have a question on your 4:2:0 illustration. Is it really a line of Cr followed by a line of Cb, or do they alternate across the line? i.e.: Cb Cb Cb Cb Cb Cr Cr Cr Cr Cr vs. Cb Cr Cb Cr Cb Cr Cb Cr Cb Cr Of course, I wouldn't be surprised if it could be either... but I wonder which is more common. -Steve

July 6th, 2005, 07:03 AM	#6
Matt Watkinson Tourist Join Date: Jun 2005 Posts: 3	Thanks for the advice. I appreciate the concern, but having read around a bit it seems likely that the real problem is that the documentary makers don't know too much about the technical side of things - while I didn't provide any details in my first post, they are barely more experienced than I am (although there has clearly been some confusion over the kind of camera I need - they would never have expected me to get anything that pricey). The main reason that they wanted me to do it is that I have specialist knowledge of the field that they're investigating and can speak pretty decent Japanese (and English, although hopefully that's apparent from my writing...). On reflection it's most likely a task that's technically beyond me. Probably the best thing to do would be to investigate hiring people with the correct knowledge and equipment, and I can just do the talking! I am, however, pretty confident that it's more a case of crossed wires than anything. I've known these guys for 10 years or so and have complete faith in them. Just have to wait for them to come back from their holiday...

July 6th, 2005, 07:10 AM	#7
Matt Watkinson Tourist Join Date: Jun 2005 Posts: 3	Also, just for my personal interest: The article that Graeme kindly linked to, while quite difficult reading for someone unfamiliar with the subject, was most illuminating. It seems to suggest that you can 'upsample' other types of footage into 4:2:2 quality using software routines. Is this the case? Of course, I understand that any post-shooting process is not going to be able to suddenly add new data to the image that was not there before, but presumably it would make the footage 'compatible' with other 4:2:2 stuff (ie could be edited into the same footage). As I'm not actually going to have to film anything that's high speed/high colour/complicated in any way but rather just a guy sitting there and talking, the difference might not be so notable...maybe?? I think I'm a little out of my depth! Still, it's interesting to learn about it.