Wind against HVX

alpi69

alpi69

Veteran
well as I said before. there are people trying hard to discredit the HVX in my area.
http://www.vcm-markt.de//geraete_details.php?geraete_id=2761
the link is german, but basically they say Panasonic is cheating, because they bring a HDready cam, but not a true HD cam.
they further say the 4:2:2 is actually 3:1,5:1,5 and the Chips are 960x720. Since the cam has to do a lot of interpolation it is bad quality. the same vendor just ordered 5 Canon H1 and sells them happily......for 7.200 (the HVX is 10.000)

If you now add all the confusion with the prices/bundles etc by Europe´s marketing you understand why Panasonic never gets taken serious over here.

I will not care as long as the image is ok, but many also professionals (in broadcast) simply go after numbers just like the stillcamera prosumer goes after megapixels.
 
well maybe Jan should tell Pana Europe to start a campaign then, because these numbers are spreading in Munich which is a rather big broadcasting town.
 
Stevet said:
Jan has stated that the CCDs are NOT 960x720 !
Click to expand...
Jan cannot say the size of HVX200 CCDs because she is remote controlled representative by Panasonic who's banned info about that important thing for all users of low-cost HD cameras. She is locked on that info. Now I can quote Steve Mullen who is writing at the moment from South of India the following text for VideoSystems 'Panasonic HVX200 DVCPRO HD camcorder set to arrive':

"One open question at the time I’m writing this in Asia is the native resolution of its CCDs. Panasonic has not disclosed this number. With a VariCam camera, the CCDs are 1280x720. While it’s possible the HVX200 will also have three of these very high-resolution CCDs, it is more likely that 960x720-element CCDs will be used to avoid the excess heat generated when 1280x720 1/3in. CCDs are clocked at 50Hz or 60Hz.

With 960x720 pixel CCDs, 720p DVCPRO HD would be generated directly. (It’s not obvious what advantage there would be to using green shift to create 1280 pixels and then pre-filtering the signal back to 960 pixels.)

The pixel aspect ratio of a 960x720 CCD would be 1.33:1, and the recorded 960x720 image would have a 4:3 aspect ratio. (The CCDs themselves of the HVX200 are, of course, native 16:9.) Therefore, unlike 720p HDV, DVCPRO PRO HD provides a non-square pixel-ratio and a lower horizontal resolution.

With the potential 1.33X additional luma information from green shift, 1280 samples of luma could be obtained from a 960-pixel CCD that would support 1080i DVCPRO HD. Vertical green shift could also be employed to generate 1080 lines from 720-row CCDs. Assuming a 1.5X factor, a 720-row pixel could yield 1080 lines."
Link:
http://www.videosystems.com/e-newsletters/12192005_hdvwork/#1
 
I've read about Canon Xl H1 as a "mini CineAlta" from Shannon Rawl that has bought it. He posts some pics in dvinfo, the pictures look very good.
Canon specs are clear, Panasonic still doesn't want share the specs of its camera.
I hope they don't make tricks to customers, because money has value!
I really hope that "4:2:2 is actually 3:1,5:1,5" is not true, because eliminating Gop problems (as Canon seems do with their new technology) we oughta buy a camera with wrong specs, this involves in problems with colours when do color correction or others things.
I hope when camera is out, someone with culture and knowledge, let understand us what Panasonic want hide about this specs.
I'm waiting for this camera for LONG TIME, and I've trust in Panasonic having seen the innovation introduced with Dvx100, but if they can't provide the TRUE Hd tecnology, they must admit it. They could have made a sweet camera, but standards are standards in pro world, they can't lie to pro-world.
They could lie to simple customer that has not knowledge but it could be happen, that the poor guy made some work and discovers that he can't sell it to no-one company, because their technicians know the true story.
This company's people can open the camera, study the specs, so Panasonic lost his reputation. So they must tell the truth!
I've some doubt regarding the fact that Panasonic didn't accept Hdv format, this was a great idea, but they could have made some mistakes discovering that the stuff that they wanted be into Hvx200 cost much money!
So they could be in embarrassment for it, and when they discover this they can't come back after the advertsing propaganda.
I hope that this story will be clear, for Panasonic and for us!

Cheers:)
 
Stevet said:
Jan has stated that the CCDs are NOT 960x720 !
Click to expand...

doesn't mean it's more though
(sorry - I am just being a trouble maker)
but...
Things like this keep me from putting down a deposit when Pre odering the Cam -

Thanks to Rush for providing a preorder list for us folks who also wanna wait and see what is what before we order.

and be happy too that all these people like me are not ahead of you on a list...So you will get your camera sooner
 
alpi69 said:
I will not care as long as the image is ok, but many also professionals (in broadcast) simply go after numbers just like the stillcamera prosumer goes after megapixels.
Click to expand...
I'll second that sentiment, which is why I look forward to seeing the results of tests in real life, real cameras filming real subjects. Lets see which resolves the most on a test chart, and which looks best on real life subjects. All that will be a function of a combination of imaging chip, processing, recording format and the subject itself. One camera may look best for a scene with fine detail/little movement, another when the detail is coarse but a lot of motion.

That said, Panasonic themselves are very keen to quote numbers when it suits them, less so when it doesn't, and this "3:1.5:1.5" is a good case in point.

I'll ignore the no of pixels on the chip issue (much to everybodys relief) and look solely at recording system resolutions. DVCPRO HD records a luminance matrix of 960x720 and two chrominance matrices of 480x720 which Panasonic refers to as 4:2:2. HDV 1 records a luminance matrix of 1280x720, and two chrominance matrices of 640x360 which is referred to as 4:2:0. Panasonic will happily tell you that one advantage of DVCPRO HD over HDV1 is the improved colour space - 4:2:2 v 4:2:0, but when they're referenced to different luminance matrices that's a very misleading statement, if not strictly untrue.

When both codecs are referenced to the 720 square pixel matrix, DVCPRO HD does indeed become 3:1.5:1.5, whilst HDV1 remains 4:2:0. The former has inferior resolution horizontally for both luminance and chrominance, though double the vertical chrominance resolution. Obviously there are other issues - the I frames of HDV1 are less compressed than the frames of DVCPRO HD, but HDV1 is interframe compression and less good at handling motion.

None of this is to say that the HVX200 is not a true HD camera. (It is.) It's not to agree with "Since the cam has to do a lot of interpolation it is bad quality....." - I think it's quality will actually be quite good. I just object to Panasonic saying that numbers don't matter when pixel counts are talked about, then making much about misleading "4:2:2 and 4:2:0" references. It's quite justifiable to talk about a lum matrix of 4x4 and chrom matrices of 4x2 pixels as a "4:2:2" system, after all.........:laugh:
 
If anybody wants a reference to Panasonic referring to this issue, from Tosh Bilowski comes the following quote:

"Back to DVCPRO HD, another advantage is the 4:2:2 color space versus 4:2:0 found on HDV. That means richer detail, better handling of color changes and better color rendering. This is huge, if you like color."

How 960 luma samples horizontally v 1280, and 480 chroma v 640 can give "richer detail, better handling of color changes" I'm not sure, unless Mr Bilowskis eyes are more sensitive to vertical resolution than horizontal..........
 
Please....3:1.5:1.5?
It's means exactly the same as 4:2:2.

Same as saying that 0.5 is really not expressed by the fraction 1/2, but 2/4 instead, doesn't make sense.
 
Thanks for bringing that up, Anders. I was wondering the same thing. Am I missing something? They are all ratios, right? Thus the colons?


Let's get a colonoscopy in here, STAT!.



:grin:
 
Maybe "http://www.vcm-markt.de/" are tired of all the european customers waiting out for the HVX-200 release in March 2006, instead of buying a system from them ASAP.....
 
Anders Holck said:
Please....3:1.5:1.5?
It's means exactly the same as 4:2:2.
Click to expand...
Not really. Not when you're comparing two systems with differing horizontal resolutions such as HDV1 and DVCPRO HD. If you define (correctly) HDV1 as 4:2:0, with 1280 luminance samples per line, then if you want to compare such as DVCPRO HD directly with it, the same base should be used - 1280. Hence DVCPRO HD (with 960 luminance samples, 3/4 that of HDV1) can properly be considered 3:1.5:1.5.

If 1280 is "4", 960 is "3", that's where the reference comes from. If you're not comparing systems DVCPRO HD can indeed be referred to as 4:2:2. When, like Tosh, you are, I feel like should be compared with like - hence the 3:1.5:1.5 compared to 4:2:0.
 
You're discussing semantics.

4:2:2 is a RATIO
To say that 4:2:2 is actually 3:1.5:1.5 isn't really saying anything.
It woudl be the same as saying 2:1:1, or 8:4:4

Ratios.


EDITED TO ADD:
Sorry, didn't see the second page.
Anders covered this already.
 
Luis Caffesse said:
You're discussing semantics.

4:2:2 is a RATIO
To say that 4:2:2 is actually 3:1.5:1.5 isn't really saying anything.
It woudl be the same as saying 2:1:1, or 8:4:4

Ratios.
Click to expand...

I think this is not quite true. The first digit refers to the luma-signal of 4 pixels on a square matrix. 4:x:y means 4 out of 4 pixels are recorded. 2:x:y would mean you loose half the luma-resolution. 8:x:y means you have more information recorded than there really is.

But there is no 3:1.5:1.5. Ever seen a 1,5 pixel? Or a 3/4 bit? All this calculations refer to the encoding-process and have nothing to do how the CCD produces the picture.
 
MarcusX said:
2:x:y would mean you loose half the luma-resolution. 8:x:y means you have more information recorded than there really is.
Click to expand...
Luminance is not always 4, HDCAM is officially a 8-bit YUV 3:1:1 system.

The reason behind this is more awkward. Here is a quote from Charles Poynton's excellent PDF (http://www.poynton.com/PDFs/Chroma_subsampling_notation.pdf)

"The first digit originally specified luma sample rate relative to 3 3⁄8 MHz.
(The commonly used leading digit of 4 is a historical reference to a sample rate roughly four times the NTSC or PAL color subcarrier frequency, when subcarrier-locked sampling was under discussion for component video.)
HDTV was once supposed to be described as 22:11:11! The leading digit has, thankfully, come to be relative to the
sample rate in use.
Until recently, the initial digit was always 4, since all chroma ratios have been powers of two– 4, 2, or 1.
However, 3:1:1 subsampling has recently been commercialized in an HDTV production system (Sony’s HDCAM)..."

"Originally, the second digit specified the horizontal subsampling of CB and the third digit specified the horizontal subsampling of CR.
That scheme failed to anticipate vertical subsampling, and in any event, all practical systems have the same subsampling ratios for both CB and CR. So, in today’s notation, the second digit specifies the horizontal subsampling of both CB and CR with respect to luma.
The third digit now has two possibilities. If the third digit is the same as the second digit, there is no vertical subsampling.
If the third digit is zero, this indicates 2:1 vertical subsampling of both CB and CR ...."
 
Luis Caffesse said:
To say that 4:2:2 is actually 3:1.5:1.5 isn't really saying anything.
It woudl be the same as saying 2:1:1, or 8:4:4
Click to expand...
Completely untrue. What it is really saying is that the horizontal resolution of DVCPRO HD is 3/4 that of HDV1 - 960 as opposed to 1280.

Using the same logic, then compared to HDV1 and it's luminance matrix of 1280x720, and referring to that as 4:2:0, 2:1:1 could be taken to mean a system with Lum resolution of 640x720 whilst with 8:4:4 a system of 2560x720 is implied.

Putting it another way, if we do (quite correctly, they are only ratios as you say) refer to DVCPRO HD as 4:2:2, then HDV1 should (IF COMPARED DIRECTLY) be referred to as 5.333:2.667:0 !!!

And since Tosh for one IS comparing directly, then we're not discussing semantics, but potentially misleading claims.
 
MarcusX said:
But there is no 3:1.5:1.5. Ever seen a 1,5 pixel? Or a 3/4 bit?
Click to expand...
The 1.5 refers not to pixels but ratios, and the rationale is to refer it to 4 when "4" represents square pixel sampling - 1920 for 1080 systems, 1280 for 720. Hence HDV1 can properly start with "4" ("2:0" then following naturally) whilst DVCPRO HD should rightly start with "3". As should HDCAM with it's horizontal resolution of 1440 - 3/4 that of "square pixel" 1080.
 
harddrive said:
Completely untrue. What it is really saying is that the horizontal resolution of DVCPRO HD is 3/4 that of HDV1 - 960 as opposed to 1280.

Using the same logic, then compared to HDV1 and it's luminance matrix of 1280x720, and referring to that as 4:2:0, 2:1:1 could be taken to mean a system with Lum resolution of 640x720 whilst with 8:4:4 a system of 2560x720 is implied.

Putting it another way, if we do (quite correctly, they are only ratios as you say) refer to DVCPRO HD as 4:2:2, then HDV1 should (IF COMPARED DIRECTLY) be referred to as 5.333:2.667:0 !!!

And since Tosh for one IS comparing directly, then we're not discussing semantics, but potentially misleading claims.
Click to expand...


Fair enough. I was being a bit of a smart ass anyhow. Sorry about that.
I probably shouldn't have jumped into this thread.

We all seem to understand that DVCProHD has a luma matrix of 960x720, yet is referred to as 4:2:2. So everyone seems to be on the same page here.
I understand your point about comparing it to HDV1....so, okay.
If that's how you'd prefer to refer to it...it's fine by me.

But just because "Tosh" is comparing them directly, doesn't mean this isn't semantics. I can see your point though, it suppose it could be misleading.
Semantics often are. That's the problem with leaning too heavily on specs as opposed to an actual image.
 
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