What is best?
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Loki
Veteran
Re: What is best?
DVCAM is just a more stable tape format. it writes the data over a larger space on the tape, therefore has less dropout.. the tape runs faster through the write heads.. gives you slightly less recording time..
I am positive here... the Z1 does not shoot DVCPRO.. that is a panasonic format.
the Sony cam shoots, HDV, DV, and DVCAM... DV and DVCAM = same picture quality.
Cpt. Jack, I don't think your question makes too much sesne.. what problems might you be referring to? Editing Progressive vs. Interlaced should never cause problems...
Are you talking about the HDV editing as the "problem" because of the MPEG2 compression?
And shaw I think you meant DVCPROHD has a 100MBps data rate...
DVCPRO25 = 25MBps(Normal DV 4:1:1)
DVCPRO50 = 50MBps(4:2:2)
DVCPROHD = 100MBps(4:2:2)
DVCAM is just a more stable tape format. it writes the data over a larger space on the tape, therefore has less dropout.. the tape runs faster through the write heads.. gives you slightly less recording time..
I am positive here... the Z1 does not shoot DVCPRO.. that is a panasonic format.
the Sony cam shoots, HDV, DV, and DVCAM... DV and DVCAM = same picture quality.
Cpt. Jack, I don't think your question makes too much sesne.. what problems might you be referring to? Editing Progressive vs. Interlaced should never cause problems...
Are you talking about the HDV editing as the "problem" because of the MPEG2 compression?
And shaw I think you meant DVCPROHD has a 100MBps data rate...
DVCPRO25 = 25MBps(Normal DV 4:1:1)
DVCPRO50 = 50MBps(4:2:2)
DVCPROHD = 100MBps(4:2:2)
Re: What is best?
[quote author=powerdog link=board=HDV;num=1108231269;start=15#18 date=02/13/05 at 00:57:22]Somewhat OT, but speaking of HD and what's best: I was just feasting my eyes on the HD cam used for the movie Collateral. The LCD viewfinder alone is a $10K accessory!
http://bssc.sel.sony.com/Professional/webapp/ModelInfo?m=0&sm=0&p=2&sp=19&id=75222[/quote]
I love that! $135,002.00 US price.
Nope, sorry; $135K is my limit; that two bucks kills the deal!
[quote author=powerdog link=board=HDV;num=1108231269;start=15#18 date=02/13/05 at 00:57:22]Somewhat OT, but speaking of HD and what's best: I was just feasting my eyes on the HD cam used for the movie Collateral. The LCD viewfinder alone is a $10K accessory!
http://bssc.sel.sony.com/Professional/webapp/ModelInfo?m=0&sm=0&p=2&sp=19&id=75222[/quote]
I love that! $135,002.00 US price.
Nope, sorry; $135K is my limit; that two bucks kills the deal!
Barry_Green
Moderator
Re: What is best?
For clarification: DV, DVCAM, and DVCPRO (also known as DVCPRO25) are all basically identical, as far as the bits on tape are concerned. DVCAM uses the same tape as DV but runs the tape faster through the camera, spreading the data across a larger surface area of the tape, which makes for more reliable recording and better interfacing with linear editing. DVCPRO uses a different tape formulation for more reliability, among other things.
They're all 25mbps 4:1:1 formats. In PAL it's a little different, DVCPRO is still 4:1:1 whereas DV and DVCAM are 4:2:0.
DVCPRO50 is an enhancement to the DVCPRO format. It somehow gangs two DV codecs together to record twice the data rate, at a lower compression ratio, so you get 3.3:1 compression and 4:2:2 color sampling. DVCPRO50 is frequently compared to Digital Betacam for quality; DVCPRO50 is, I believe, bitstream compatible with JVC's D-9/Digital-S format.
DVCPRO-HD takes it one step further, doubling the data rate again to 100 megabits, and providing for native 720p or 1080i recording, while retaining the 4:2:2 color sampling.
So DVCAM mode on the Z1 will do nothing about the 15-frame dropout issue, because DVCAM mode means you're recording in standard-def, not high-def. The 15-frame dropout issue is limited exclusively to the HDV high-def mode. Now, using DVCAM tapes might help avoid the dropout issue some, because DVCAM tapes are theoretically engineered to a higher quality standard and should be more dropout-resistant... but that's not shooting in DVCAM mode, you understand. That's shooting in HDV mode, and choosing to record on a DVCAM tape. Personally, if I was using a Z1, I'd only use the Sony $18 HDV tapes that they introduced specifically for this camera.
For clarification: DV, DVCAM, and DVCPRO (also known as DVCPRO25) are all basically identical, as far as the bits on tape are concerned. DVCAM uses the same tape as DV but runs the tape faster through the camera, spreading the data across a larger surface area of the tape, which makes for more reliable recording and better interfacing with linear editing. DVCPRO uses a different tape formulation for more reliability, among other things.
They're all 25mbps 4:1:1 formats. In PAL it's a little different, DVCPRO is still 4:1:1 whereas DV and DVCAM are 4:2:0.
DVCPRO50 is an enhancement to the DVCPRO format. It somehow gangs two DV codecs together to record twice the data rate, at a lower compression ratio, so you get 3.3:1 compression and 4:2:2 color sampling. DVCPRO50 is frequently compared to Digital Betacam for quality; DVCPRO50 is, I believe, bitstream compatible with JVC's D-9/Digital-S format.
DVCPRO-HD takes it one step further, doubling the data rate again to 100 megabits, and providing for native 720p or 1080i recording, while retaining the 4:2:2 color sampling.
I'm not sure I understand this question either. Are you referring to tape dropouts causing 15 frames to be lost? If so, I think I know where you're coming from. There's a common confusion that somehow DVCAM will help prevent that on the Z1. But that's a completely misunderstood view of the situation. You can't record HDV data in DVCAM format. DVCAM is a standard-def format, 720x480. So if you put the Z1 in DVCAM mode, you will *not* be recording high-def video, you'll be recording regular standard-def video (no different than if you put the camera in DV mode). DVCAM will help prevent dropouts as compared to DV mode, but even if a dropout hits in DV or DVCAM mode, it'll only affect maybe 1 frame. When in HDV mode you're using MPEG-2 compression, and dropouts cause a loss of 15 frames. You cannot record HDV/MPEG-2 when in DVCAM mode. It's not possible. It's like trying to run a gasoline car on diesel fuel -- they're just completely not the same thing at all.
So DVCAM mode on the Z1 will do nothing about the 15-frame dropout issue, because DVCAM mode means you're recording in standard-def, not high-def. The 15-frame dropout issue is limited exclusively to the HDV high-def mode. Now, using DVCAM tapes might help avoid the dropout issue some, because DVCAM tapes are theoretically engineered to a higher quality standard and should be more dropout-resistant... but that's not shooting in DVCAM mode, you understand. That's shooting in HDV mode, and choosing to record on a DVCAM tape. Personally, if I was using a Z1, I'd only use the Sony $18 HDV tapes that they introduced specifically for this camera.
Re: What is best?
[quote author=Barry_Green link=board=HDV;num=1108231269;start=0#4 date=02/12/05 at 12:27:04]In 1080i, HDV is 25-megabit data. DVCPRO-HD is 4 times the bandwidth, at 100 megabits. In 720p, HDV is 19-megabits, DVCPRO-HD is 5 times the bandwidth, at 100 megabits.[/quote]
At the risk of sounding like a one-trick pony, isn't the comparison of data rates at 720p a little unfair? When talking about quality vis-a-vis bandwidth, it seems to me that the important statistic is actually megabits per frame rather than megabits per second. It just happens that most video runs at the same frame rate, so comparisons of megabits per second usually work fine.
In this case, though, that doesn't hold true, since 100 Mbps 720p DVCPROHD is 60fps, and DVCPROHD does not use the whole bandwidth when the frame rate is lower. Thus, there is only 50Mbps of unique information when 720p DVCPROHD is running at 30fps or about 42Mbps when 720p DVCPROHD is running at 25fps. So, I would say that this is a more valid comparison:
at 720p30: DVCPROHD 50Mbps HDV 19Mbps (DVCPROHD 2.6 times greater)
at 720p25: DVCPROHD 42Mbps HDV 19Mbps (DVCPROHD 2.2 times greater)
Note that this argument does not hold for 1080i footage. As near as I can tell, 1080i in DVCPROHD runs at 60i and 50i (the same frame rates as 1080i HDV) and doesn't seem to have the same variable frame rate pulldown that 720p does.
Also note that I agree with Barry that DVCPROHD is probably a better format for many reasons; I just thought that the data rate comparison wasn't fair.
Edited to add: I realized a corollary to this is that DVCPRO50 is significantly less compressed than DVCPROHD at 720p. Since DVCPROHD 720p30 has exactly twice as many pixels as DVCPRO50 at the same data rate (50 Mbps) and the same color sampling (4:2:2), DVCPROHD 720p is twice as compressed as DVCPRO50. If you run through the math, you will also find that 720p DVCPROHD has a 1.3 times higher compression rate than even normal DV, although this may be compensated for by the fact that it samples color at twice the rate of DV.
Edited again to add: Looking further into HDV, I found that 720p50 and 720p60 are also part of the spec, although I'm not sure any products support these flavors. Clearly, the 50p and 60p versions of HDV would have more compression issues than 25p or 30p HDV since they fit twice as many frames in the same bandwidth. At 720p60, Barry's original claim that DVCPROHD has about 5 times the bandwidth of 720p HDV is correct. At 720p50, DVCPROHD has about 4.4 times the bandwidth of HDV.
[quote author=Barry_Green link=board=HDV;num=1108231269;start=0#4 date=02/12/05 at 12:27:04]In 1080i, HDV is 25-megabit data. DVCPRO-HD is 4 times the bandwidth, at 100 megabits. In 720p, HDV is 19-megabits, DVCPRO-HD is 5 times the bandwidth, at 100 megabits.[/quote]
At the risk of sounding like a one-trick pony, isn't the comparison of data rates at 720p a little unfair? When talking about quality vis-a-vis bandwidth, it seems to me that the important statistic is actually megabits per frame rather than megabits per second. It just happens that most video runs at the same frame rate, so comparisons of megabits per second usually work fine.
In this case, though, that doesn't hold true, since 100 Mbps 720p DVCPROHD is 60fps, and DVCPROHD does not use the whole bandwidth when the frame rate is lower. Thus, there is only 50Mbps of unique information when 720p DVCPROHD is running at 30fps or about 42Mbps when 720p DVCPROHD is running at 25fps. So, I would say that this is a more valid comparison:
at 720p30: DVCPROHD 50Mbps HDV 19Mbps (DVCPROHD 2.6 times greater)
at 720p25: DVCPROHD 42Mbps HDV 19Mbps (DVCPROHD 2.2 times greater)
Note that this argument does not hold for 1080i footage. As near as I can tell, 1080i in DVCPROHD runs at 60i and 50i (the same frame rates as 1080i HDV) and doesn't seem to have the same variable frame rate pulldown that 720p does.
Also note that I agree with Barry that DVCPROHD is probably a better format for many reasons; I just thought that the data rate comparison wasn't fair.
Edited to add: I realized a corollary to this is that DVCPRO50 is significantly less compressed than DVCPROHD at 720p. Since DVCPROHD 720p30 has exactly twice as many pixels as DVCPRO50 at the same data rate (50 Mbps) and the same color sampling (4:2:2), DVCPROHD 720p is twice as compressed as DVCPRO50. If you run through the math, you will also find that 720p DVCPROHD has a 1.3 times higher compression rate than even normal DV, although this may be compensated for by the fact that it samples color at twice the rate of DV.
Edited again to add: Looking further into HDV, I found that 720p50 and 720p60 are also part of the spec, although I'm not sure any products support these flavors. Clearly, the 50p and 60p versions of HDV would have more compression issues than 25p or 30p HDV since they fit twice as many frames in the same bandwidth. At 720p60, Barry's original claim that DVCPROHD has about 5 times the bandwidth of 720p HDV is correct. At 720p50, DVCPROHD has about 4.4 times the bandwidth of HDV.
magicdavek
Well-known member
Re: What is best?
[quote author=Barry_Green link=board=HDV;num=1108231269;start=0#4 date=02/12/05 at 12:27:04]HDV can be recorded on $4 miniDV tape. I don't know that DVCPRO-HD can, but we'll see. [/quote]
It would be great if Panasonic took the simple idea used with the Digital8 format. It uses Hi8 2 hour tapes and records and plays back the tapes at half speed so you get better video (Digital8 vs. Hi8 ) but only 1 hour on that two hour tape.
If only the DVCPRO-HD would record to standard MiniDV tapes, say 20 minutes per 1 hour tape. While a pain for event videographers, it would be great for filmmakers. However, why would Panasonic do such a thing if they can make a bundle on the P2 cards?
[quote author=Barry_Green link=board=HDV;num=1108231269;start=0#4 date=02/12/05 at 12:27:04]HDV can be recorded on $4 miniDV tape. I don't know that DVCPRO-HD can, but we'll see. [/quote]
It would be great if Panasonic took the simple idea used with the Digital8 format. It uses Hi8 2 hour tapes and records and plays back the tapes at half speed so you get better video (Digital8 vs. Hi8 ) but only 1 hour on that two hour tape.
If only the DVCPRO-HD would record to standard MiniDV tapes, say 20 minutes per 1 hour tape. While a pain for event videographers, it would be great for filmmakers. However, why would Panasonic do such a thing if they can make a bundle on the P2 cards?
Flintstone
Well-known member
Re: What is best?
What would be awesome is to have native recording to hard disk. You can get 100GB 2.5" hard drives nowadays. It's much smaller then a tape transport, and slightly larger then P2 cards. The drive could be removable too. This type of solution would be ideal for event videographers... heck, even filmmakers would love it.
But the leak for the HDX said it would be P2 and tape. I'm not sure that using MiniDV tapes would be the best choice, but it would certainly make fiscal sense. Alas, 15 to 20 minutes max on tape would be a drag.
What would be awesome is to have native recording to hard disk. You can get 100GB 2.5" hard drives nowadays. It's much smaller then a tape transport, and slightly larger then P2 cards. The drive could be removable too. This type of solution would be ideal for event videographers... heck, even filmmakers would love it.
But the leak for the HDX said it would be P2 and tape. I'm not sure that using MiniDV tapes would be the best choice, but it would certainly make fiscal sense. Alas, 15 to 20 minutes max on tape would be a drag.