color sampling
- Thread starter smelni
- Start date
Barry_Green
Moderator
Adam Wilt explains color sampling on his site here:
http://adamwilt.com/DV-FAQ-tech.html#colorSampling
Basically 4:4:4 means one color sample for every black & white sample
4:2:2 means one color sample for every two black & white samples
4:2:0 and 4:1:1 mean one color sample for every four black & white samples
Obviously 4:4:4 is much higher color resolution than 4:1:1 is.
NTSC DV uses 4:1:1. HDV uses 4:2:0.
The JVC is 4:2:0 in 720p, and 4:1:1 in DV. The HVX is 4:2:2 in all modes (except DV, of course, which is always 4:1:1). (unless you're in PAL territory, in which case DV is 4:2:0). (Unless you're using DVCPRO25, in which case PAL DVCPRO25 is 4:1:1 as well.)
Okay, so let's sum it up another way: the JVC records chroma resolution at 640x360. The HVX in 720p mode records chroma at 480x720, or 50% more chroma resolution than the HD100. In 1080 mode the HVX records chroma at 640x1080, or three times as much chroma resolution as the HD100.
The Z1 records chroma at 720x540. The HVX does it at 640x1080, or 78% more chroma resolution than the Z1 (or any 1080i HDV).
http://adamwilt.com/DV-FAQ-tech.html#colorSampling
Basically 4:4:4 means one color sample for every black & white sample
4:2:2 means one color sample for every two black & white samples
4:2:0 and 4:1:1 mean one color sample for every four black & white samples
Obviously 4:4:4 is much higher color resolution than 4:1:1 is.
NTSC DV uses 4:1:1. HDV uses 4:2:0.
The JVC is 4:2:0 in 720p, and 4:1:1 in DV. The HVX is 4:2:2 in all modes (except DV, of course, which is always 4:1:1). (unless you're in PAL territory, in which case DV is 4:2:0). (Unless you're using DVCPRO25, in which case PAL DVCPRO25 is 4:1:1 as well.)
Okay, so let's sum it up another way: the JVC records chroma resolution at 640x360. The HVX in 720p mode records chroma at 480x720, or 50% more chroma resolution than the HD100. In 1080 mode the HVX records chroma at 640x1080, or three times as much chroma resolution as the HD100.
The Z1 records chroma at 720x540. The HVX does it at 640x1080, or 78% more chroma resolution than the Z1 (or any 1080i HDV).
Graeme_Nattress
Red Team
http://www.nattress.com/Chroma_Investigation/chromasampling.htm
also has some more info on chroma sampling. One thing Barry hasn't mentioned, that 4:2:0 works differently for interlaced and progressive video. In progressive, it's not too bad, but in interlace, it gets really messy indeed, and is quite awful.
Graeme
also has some more info on chroma sampling. One thing Barry hasn't mentioned, that 4:2:0 works differently for interlaced and progressive video. In progressive, it's not too bad, but in interlace, it gets really messy indeed, and is quite awful.
Graeme
STORYTELLER32
Well-known member
Question for you Barry (et al):
So let's say we have the HVX, but not a computer (yet) to capture and edit HD footage. But you're dying to shoot a flik and can work in post with SD footage. Is there a way to get the 4:2:2 color space in SD from that camera? I heard that you can down convert in camera from 720 to SD before recording to tape in camera. Is that true? And if so, would that give us a 4:2:2 color space image in SD output from that tape?
So let's say we have the HVX, but not a computer (yet) to capture and edit HD footage. But you're dying to shoot a flik and can work in post with SD footage. Is there a way to get the 4:2:2 color space in SD from that camera? I heard that you can down convert in camera from 720 to SD before recording to tape in camera. Is that true? And if so, would that give us a 4:2:2 color space image in SD output from that tape?
Barry_Green
Moderator
If you don't have a computer to capture with, and you want the 4:2:2 color, you'll need either a P2 card or a FireStore (or comparable device).
The camera in its bare, base configuration has only a DV tape drive onboard. DV is 4:1:1 and that's all there is to that.
You can downconvert in camera, but it requires that you shot 720p onto a P2 card and then you can downconvert in realtime to 4:1:1 DV.
If you want DVCPRO50 4:2:2 SD, you'll need something other than DV tape to capture it with. That means a P2 card, or a DVCPRO50-enabled FireStore, or a connection to a computer, etc.
The camera in its bare, base configuration has only a DV tape drive onboard. DV is 4:1:1 and that's all there is to that.
You can downconvert in camera, but it requires that you shot 720p onto a P2 card and then you can downconvert in realtime to 4:1:1 DV.
If you want DVCPRO50 4:2:2 SD, you'll need something other than DV tape to capture it with. That means a P2 card, or a DVCPRO50-enabled FireStore, or a connection to a computer, etc.
The cheapest way might be to find someone with a laptop with firewire and buy an external Hard Drive if you are planning on shooting a lot on one day. For under $100.- you can get an 80G. Just ask around if someone has a laptop like such and try to borrow it (but buy the man some beer). You will however have limited mobility as you will have to carry the laptop behind the camera operator. If this laptop's internal HDD fills up, you can move the footage to the external HDD and then go back to shooting... you might also need a power inverter (~$40.-) to get power from a car's cigarette lighter if you don't have power outlets nearby.
The next cheapest way is to buy a Firestore or comparable device which are basically pumped up (way pumped up) iPods. You can get an 80G with HD capabilities for about $1400.- ($1300.- for the device and $100.- for the HD HD software ). That price though, might be changing a bit by the time the HVX comes out (I think it should :angry: ). There are cheaper 40G ones out there for ~$650.- plus the ~$100.- HD software: ~$750.-
Then the next one and the best one: P2 cards... better in my opinion anyway. You will have to shed a bunch on money to buy at least one 8G card. The smaller 4G cards are not really that wise of an investment because they will limit your shot lengh a little too much. The 8G cards are $2000.- and you will still need the laptop (beer, external HDD ~$100.- and the power inverter ~$40.-). However, every time you fill up your card, you will have the footage, ready to be edited and basically allready in the computer. If this was a nice laptop, you could start editing right then and there as you keep shooting. Also, the way to go really is two cards, but that's an other $2000.-. These too will drop in price as bigger ones come out and hopefully when they realize that they will sell a bunch more of them if the lower the price a bit. All of this will happen slowly... Just to cheer ourselves up, let's remind ourselves that 16G cards (using 4 2G SD chips) are in the works as some of the in-the-know and more knowledgeable guys in this forum mentioned. When those come out we should (if we were good boys) see a price drop on the 8G cards.
The next cheapest way is to buy a Firestore or comparable device which are basically pumped up (way pumped up) iPods. You can get an 80G with HD capabilities for about $1400.- ($1300.- for the device and $100.- for the HD HD software ). That price though, might be changing a bit by the time the HVX comes out (I think it should :angry: ). There are cheaper 40G ones out there for ~$650.- plus the ~$100.- HD software: ~$750.-
Then the next one and the best one: P2 cards... better in my opinion anyway. You will have to shed a bunch on money to buy at least one 8G card. The smaller 4G cards are not really that wise of an investment because they will limit your shot lengh a little too much. The 8G cards are $2000.- and you will still need the laptop (beer, external HDD ~$100.- and the power inverter ~$40.-). However, every time you fill up your card, you will have the footage, ready to be edited and basically allready in the computer. If this was a nice laptop, you could start editing right then and there as you keep shooting. Also, the way to go really is two cards, but that's an other $2000.-. These too will drop in price as bigger ones come out and hopefully when they realize that they will sell a bunch more of them if the lower the price a bit. All of this will happen slowly... Just to cheer ourselves up, let's remind ourselves that 16G cards (using 4 2G SD chips) are in the works as some of the in-the-know and more knowledgeable guys in this forum mentioned. When those come out we should (if we were good boys) see a price drop on the 8G cards.
I was so proud of it and now you ruined it! 
Lol! :beer:
Also:
Buying the Firestore (or comparable) device with 80G and HD capability might just be the best HD investment period around the time the HVX comes out...
If you are buying the HVX you are paying $6000.- for two reasons: Quality and Versatility/Flexibility. I believe that the additional hardware you purchase should be bought with the intent of taking advantage of all of the camera's dormant money-making potential if possible. At least I will want the ability to shoot for long periods. I cover concerts and do interviews quite often. An 80G device might even allow you to get a whole game!
Two P2 cards allow this by hot-swapping them using that really expensive belt-clipped "P2 store pack" device or whatever the name is. However, this adds up to a lot of $$$. You can use a laptop, but then you'll need a second person, unless the camera is fixed. Even in the long term future when 16G cards become let's say $500.-, the ability to plug-and-forget instead of having to swap cards while filming sounds like something that's worth $1400.- for a lot of people. Just imagine shooting hand-held for a long time and having to hot-swap on top of it, doable, but rather not have to.
So now that you bought this device you can also shoot movies in HD. You can shoot all day on one of these. You still can download it during lunch-break so you can edit and look at some of what you've shot. Then you can fill it up again. If you have complicated action scenes, long dialog-intensive scenes, if your actors are unrehearsed or even if you are working with 12th-take-Joe you should still be covered with 160G.
This is quite a confortable position to be in as you wait for the 8G P2 cards to drop in price if you love the idea of having a powerbook with FCP on a movie set using two 8G (or 16G) cards like I do.
Ok, enough talking 4 me :lipsrseal
Lol! :beer:
Also:
Buying the Firestore (or comparable) device with 80G and HD capability might just be the best HD investment period around the time the HVX comes out...
If you are buying the HVX you are paying $6000.- for two reasons: Quality and Versatility/Flexibility. I believe that the additional hardware you purchase should be bought with the intent of taking advantage of all of the camera's dormant money-making potential if possible. At least I will want the ability to shoot for long periods. I cover concerts and do interviews quite often. An 80G device might even allow you to get a whole game!
Two P2 cards allow this by hot-swapping them using that really expensive belt-clipped "P2 store pack" device or whatever the name is. However, this adds up to a lot of $$$. You can use a laptop, but then you'll need a second person, unless the camera is fixed. Even in the long term future when 16G cards become let's say $500.-, the ability to plug-and-forget instead of having to swap cards while filming sounds like something that's worth $1400.- for a lot of people. Just imagine shooting hand-held for a long time and having to hot-swap on top of it, doable, but rather not have to.
So now that you bought this device you can also shoot movies in HD. You can shoot all day on one of these. You still can download it during lunch-break so you can edit and look at some of what you've shot. Then you can fill it up again. If you have complicated action scenes, long dialog-intensive scenes, if your actors are unrehearsed or even if you are working with 12th-take-Joe you should still be covered with 160G.
This is quite a confortable position to be in as you wait for the 8G P2 cards to drop in price if you love the idea of having a powerbook with FCP on a movie set using two 8G (or 16G) cards like I do.
Ok, enough talking 4 me :lipsrseal