Panasonic HVX-200 Native Resolution - DVXuser.com -- The online community for filmmaking

BobDiaz · 12-14-2005, 08:37 PM

First of all, let me start by saying that everything I have seen at the December DV Expo West Trade Show about the Panasonic HVX-200 camera, tells me that this is one FANTASTIC camera. Compared to other HD cameras in the under $10,000 range, no other camera can come close to many of the special features it can offer. While it is possible that there is some hidden flaw (or flaws), this seems VERY unlikely. Still there is one issue about the design worth talking about. I do not consider this a design flaw, but is something worth knowing about the camera.

As far as I can find, Panasonic has NOT released any information about the native resolution of the CCDs used in the HVX-200. When I asked during the Question and Answer session about the native resolution of the CCDs, the response never answered my question. Very likely Panasonic didn't want us to get into a numbers mode and fail to consider how the camera performs. Given that JVC must use dual A/D converters per 1 MP (Mega Pixel) CCD at 60 Hz, this suggests that the image resolution of the CCDs in the Panasonic are less than 1 MP.

What follows is speculation on my part and should NOT be taken as a proven fact. All conclusions are based on the assumption that the native resolution of each CCD on the HVX-200 is 960h x 540v or about 1/2 MP. Even if my assumption is correct, Panasonic appears to applied a simple, but brilliant approach to the design, in order to obtain true HD resolution.

If Panasonic had aligned the Red, Green, and Blue CCDs so that they all cover the exact same locations, the total CCD resolution of the camera would be 960h x 540v. This is 1/2 the horizontal and 1/2 the vertical resolution of 1920h x 1080v. However, both the Red and Blue CCDs are offset from the Green CCDs by 1/2 a pixel in both the horizontal and vertical direction. This means that the center of each Red or Blue CCD element lands exactly at where the 4 corners of the Green CCD elements meet. (The offset in the Red and Blue CCDs was covered in the Panasonic HVX-200 presentation.)

With this layout, if you count the number of CCD elements in either the horizontal or vertical direction, the number doubles. That is with this offset, 960h x 540v acts like 1920h x 1980v. In theory, that holds true if the fill factor (or aperture) of each CCD pixel was 25% (or less) of the area set aside for each element. In the past, that might have been true, but today it seems unlikely, because many CCDs are using micro lenses to increase the fill factor to close to 100%. This is done to improve low light performance.

Unfortunately, the fill factor of the HVX-200's CCDs is not known. We will assume it is 100%, which gives us the best low light performance and the worst case on overlap. If so, in the horizontal (or vertical) direction, every Green Pixel is overlapped by a Red and Blue Pixel by 50% of the pixel. The overlap helps to reduce the possibility of moiré patterns, but it also reduces the increase in resolution from 2x to 1.5x. Thus 1.5x increase results in an effective resolution of 1440h x 810v. If the fill factor is less than 100%, the effective resolution is higher than 1440h x 810v. One statement made by Jan in her presentation suggests that the fill factor is less than 100%.

Even with a fill factor of 25%, horizontal (or vertical) line resolution drops from 2x to 1x when the lines or detail are at EXACTLY a 45 degree angle (either way). While true, this seems like a moot point, seeing as how most detail appears to be close to a horizontal or vertical orientation.

Remember these figures assume a worst case conditions of a fill factor of 100% and the native CCD resolution of 960h x 540v. If Panasonic used CCDs with a higher resolution and/or lower fill factor, the effective resolution of 1440h x 810v would be higher.

Even with the lower effective resolution, 1080 HDV has a resolution of 1440h x 1080v interlaced. This means that in the horizontal direction, the HVX-200 offers no better resolution that any other 1080i HDV camera. In the vertical direction the reduced effective resolution may not be significant, because all HD cameras under $10,000 may lack the ability to fully resolve 1080 lines.

As for color resolution, HDV is 4:2:0. That means that the color resolution is 1/2 the grayscale resolution in both the vertical and horizontal directions. This would be what I believe is the native CCD resolution of the HVX-200, 960h x 540v.

If we look at the 1280h x 720v resolution, the worst case effective resolution of 1440h x 810v for the Panasonic is higher than 720p mode. In that mode, effective resolution is a non-issue and the quality of the lens becomes the limiting factor.

To me it appears that the 720p modes are where the HVX-200 shines. All of the camera's VeriCam modes are supported in 720p, the P2 memory requirements are reduced (compared to 1080), and the effective resolution of the CCDs is greater than the 720p resolution.

It can be argued that the Color CCD resolution of the JVC HD-100 is 1280h x 720v. This is true, but the color information is recorded to tape as 4:2:0 or 640h x 360v. The Panasonic records color information to memory at 4:2:2 or 640h x 540v. (Remember the numbers for the Panasonic are based on a worst case guess on my part.)

Even if everything I assumed about the CCDs in the Panasonic is correct, and my guesses could be wrong, the HVX-200 blows away all the other under $10,000 HDV cameras in terms of features and flexibility. My background is electronics, computers, and manufacturing technology. I have some understanding of the design tradeoffs that must be made in creating a product. Based on what I saw at DV Expo West, Panasonic made all the right choices and produced an amazing camera.

Bob Diaz

stephenlnoe · 12-14-2005, 09:17 PM

Hi,

HDV 720p:__________Frame res 1280x720, 4:2:0, Y sample: 1280x720, Cr,Cb Sample 640x360
DVCProHD 720p:_____Frame res 1280x720, 4:2:2, Y sample: 960x720, Cr,Cb Sample 480x720

JVC (HDV1) wins in Y sample and Panasonic (DVCProHD) wins in Cr,Cb. In the end there's not much difference between the two in 720p

Jan_Crittenden · 12-15-2005, 04:56 AM

Quote:

Originally Posted by stephenlnoe

Hi,

HDV 720p:__________Frame res 1280x720, 4:2:0, Y sample: 1280x720, Cr,Cb Sample 640x360
DVCProHD 720p:_____Frame res 1280x720, 4:2:2, Y sample: 960x720, Cr,Cb Sample 480x720

JVC (HDV1) wins in Y sample and Panasonic (DVCProHD) wins in Cr,Cb. In the end there's not much difference between the two in 720p

Stephen,

If you look at this just this part of the compression scheme, you are playing with numbers and you could draw the conclusions you have. However you must keep in mind to look at how much data is there to back up that pixel map. 19Mbs or 100 Mbs. MPEG2 is a very nice transport stream but frankly it offers too much compression to be truely viable. These compression numbers mean simply the sub-sample and when you play them back they are at 720 X 1280 or in 1080i mode 1920 X 1080.

Saying that the JVC wins, doesn't take into account all that needs to be taken into account before you can even make that statement.

Best,

Jan

Policar · 12-15-2005, 05:06 AM

Bob, you may be right and that would explain the high sensetivity. Smart. Apparently pixel shift can theoretically increase resolution by root(2) pixels in a given dimension, but by simulating bayer interpolation with two colors instead of one, you're right that you can probably increase more. Whether you can get root(2) X root(2)=twice the resolution in both directions (960540 being 1/4 the pixels of 1080p) doesn't seem likely to me, but whatever.

These are the first specs Jan hasn't said are wrong (and she said 960X720) was wrong.

Also, 1080p does look a little fuzzy, though 720p look amazing (although even Canon's frame mode has a resolution drop so whatever.)

I still love the hvx for what it's worth...

Luis Caffesse · 12-15-2005, 05:19 AM

Quote:

Originally Posted by Policar

These are the first specs Jan hasn't said are wrong (and she said 960X720) was wrong.

Interesting point.

Hmm, 960x540?
I suppose that means they could be using the same exact chips that are in the XL2.
Didn't Panasonic's parent company provide those? And if I'm not mistaken they are 960x720.

How funny would that be? (well, I guess most people here wouldn't find it funny)
Would make sense why they haven't released the information.

Flintstone · 12-15-2005, 05:31 AM

Quote:

Originally Posted by Luis Caffesse

Interesting point.

Hmm, 960x540?
I suppose that means they could be using the same exact chips that are in the XL2.
Didn't Panasonic's parent company provide those? And if I'm not mistaken they are 960x720.

How funny would that be? (well, I guess most people here wouldn't find it funny)
Would make sense why they haven't released the information.

Now that would be ironic!

FatBird19 · 12-15-2005, 05:38 AM

960x540? Whoa, that's low!
If that's true, Panasonic had better provide a bunch of h.264 sample videos on their site cause I know that a large amount of consumers and propeller heads are going to see "960x540" and run away screaming. Myself, having seen the footage, know better.

Panasonic, put lot's of samples on your site. Get some of the talented people in here to make them.

JitCam · 12-15-2005, 06:35 AM

people please!

cameras are not just resolutions.. dont get caught up only into the numbers.. there are other things wirth mentioning also.. like lense.. which plays a HUGE role in overall quality and texture. i really dont think that the HVX lacks in any way in resolution. ive gotten really good images from my sony miniDV which is a single CCD cam. i think with proper lighting and good use of codecs u can get pro looking footage from this cam.

Jan_Crittenden · 12-15-2005, 08:25 AM

Unbelievable. It is not the Canon chipset! and the numbers suggested are not correct.

Best,

Jan

harlan · 12-15-2005, 10:59 AM

.

12-14-2005, 08:37 PM	#1
BobDiaz The Professor Join Date: Dec 2005 Location: L.A., Calif. Posts: 1,255	Panasonic HVX-200 Native Resolution First of all, let me start by saying that everything I have seen at the December DV Expo West Trade Show about the Panasonic HVX-200 camera, tells me that this is one FANTASTIC camera. Compared to other HD cameras in the under $10,000 range, no other camera can come close to many of the special features it can offer. While it is possible that there is some hidden flaw (or flaws), this seems VERY unlikely. Still there is one issue about the design worth talking about. I do not consider this a design flaw, but is something worth knowing about the camera. As far as I can find, Panasonic has NOT released any information about the native resolution of the CCDs used in the HVX-200. When I asked during the Question and Answer session about the native resolution of the CCDs, the response never answered my question. Very likely Panasonic didn't want us to get into a numbers mode and fail to consider how the camera performs. Given that JVC must use dual A/D converters per 1 MP (Mega Pixel) CCD at 60 Hz, this suggests that the image resolution of the CCDs in the Panasonic are less than 1 MP. What follows is speculation on my part and should NOT be taken as a proven fact. All conclusions are based on the assumption that the native resolution of each CCD on the HVX-200 is 960h x 540v or about 1/2 MP. Even if my assumption is correct, Panasonic appears to applied a simple, but brilliant approach to the design, in order to obtain true HD resolution. If Panasonic had aligned the Red, Green, and Blue CCDs so that they all cover the exact same locations, the total CCD resolution of the camera would be 960h x 540v. This is 1/2 the horizontal and 1/2 the vertical resolution of 1920h x 1080v. However, both the Red and Blue CCDs are offset from the Green CCDs by 1/2 a pixel in both the horizontal and vertical direction. This means that the center of each Red or Blue CCD element lands exactly at where the 4 corners of the Green CCD elements meet. (The offset in the Red and Blue CCDs was covered in the Panasonic HVX-200 presentation.) With this layout, if you count the number of CCD elements in either the horizontal or vertical direction, the number doubles. That is with this offset, 960h x 540v acts like 1920h x 1980v. In theory, that holds true if the fill factor (or aperture) of each CCD pixel was 25% (or less) of the area set aside for each element. In the past, that might have been true, but today it seems unlikely, because many CCDs are using micro lenses to increase the fill factor to close to 100%. This is done to improve low light performance. Unfortunately, the fill factor of the HVX-200's CCDs is not known. We will assume it is 100%, which gives us the best low light performance and the worst case on overlap. If so, in the horizontal (or vertical) direction, every Green Pixel is overlapped by a Red and Blue Pixel by 50% of the pixel. The overlap helps to reduce the possibility of moiré patterns, but it also reduces the increase in resolution from 2x to 1.5x. Thus 1.5x increase results in an effective resolution of 1440h x 810v. If the fill factor is less than 100%, the effective resolution is higher than 1440h x 810v. One statement made by Jan in her presentation suggests that the fill factor is less than 100%. Even with a fill factor of 25%, horizontal (or vertical) line resolution drops from 2x to 1x when the lines or detail are at EXACTLY a 45 degree angle (either way). While true, this seems like a moot point, seeing as how most detail appears to be close to a horizontal or vertical orientation. Remember these figures assume a worst case conditions of a fill factor of 100% and the native CCD resolution of 960h x 540v. If Panasonic used CCDs with a higher resolution and/or lower fill factor, the effective resolution of 1440h x 810v would be higher. Even with the lower effective resolution, 1080 HDV has a resolution of 1440h x 1080v interlaced. This means that in the horizontal direction, the HVX-200 offers no better resolution that any other 1080i HDV camera. In the vertical direction the reduced effective resolution may not be significant, because all HD cameras under $10,000 may lack the ability to fully resolve 1080 lines. As for color resolution, HDV is 4:2:0. That means that the color resolution is 1/2 the grayscale resolution in both the vertical and horizontal directions. This would be what I believe is the native CCD resolution of the HVX-200, 960h x 540v. If we look at the 1280h x 720v resolution, the worst case effective resolution of 1440h x 810v for the Panasonic is higher than 720p mode. In that mode, effective resolution is a non-issue and the quality of the lens becomes the limiting factor. To me it appears that the 720p modes are where the HVX-200 shines. All of the camera's VeriCam modes are supported in 720p, the P2 memory requirements are reduced (compared to 1080), and the effective resolution of the CCDs is greater than the 720p resolution. It can be argued that the Color CCD resolution of the JVC HD-100 is 1280h x 720v. This is true, but the color information is recorded to tape as 4:2:0 or 640h x 360v. The Panasonic records color information to memory at 4:2:2 or 640h x 540v. (Remember the numbers for the Panasonic are based on a worst case guess on my part.) Even if everything I assumed about the CCDs in the Panasonic is correct, and my guesses could be wrong, the HVX-200 blows away all the other under $10,000 HDV cameras in terms of features and flexibility. My background is electronics, computers, and manufacturing technology. I have some understanding of the design tradeoffs that must be made in creating a product. Based on what I saw at DV Expo West, Panasonic made all the right choices and produced an amazing camera. Bob Diaz

12-15-2005, 08:25 AM	#9
Jan_Crittenden Senior Member Join Date: Feb 2004 Location: New_Jersey, USA Posts: 2,701	Unbelievable. It is not the Canon chipset! and the numbers suggested are not correct. Best, Jan __________________ Jan Crittenden Livingston Panasonic Broadcast & TV Systems Product Manager, DVCPRO50/25, AG-DVX100B, AG-HVX200

12-15-2005, 10:59 AM	#10
harlan Senior Member Join Date: Apr 2005 Location: Los Angeles Posts: 350	. __________________ harlan "i am made of shamrocks"

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12-14-2005, 09:17 PM	#2
stephenlnoe Senior Member Join Date: Mar 2005 Location: Chicago Posts: 897	Hi, HDV 720p:__________Frame res 1280x720, 4:2:0, Y sample: 1280x720, Cr,Cb Sample 640x360 DVCProHD 720p:_____Frame res 1280x720, 4:2:2, Y sample: 960x720, Cr,Cb Sample 480x720 JVC (HDV1) wins in Y sample and Panasonic (DVCProHD) wins in Cr,Cb. In the end there's not much difference between the two in 720p

12-15-2005, 05:06 AM	#4
Policar Senior Member Join Date: Apr 2004 Location: x0\|Boston\|USA\|\|0\|0\|MA,Massachusetts Posts: 1,679	Bob, you may be right and that would explain the high sensetivity. Smart. Apparently pixel shift can theoretically increase resolution by root(2) pixels in a given dimension, but by simulating bayer interpolation with two colors instead of one, you're right that you can probably increase more. Whether you can get root(2) X root(2)=twice the resolution in both directions (960540 being 1/4 the pixels of 1080p) doesn't seem likely to me, but whatever. These are the first specs Jan hasn't said are wrong (and she said 960X720) was wrong. Also, 1080p does look a little fuzzy, though 720p look amazing (although even Canon's frame mode has a resolution drop so whatever.) I still love the hvx for what it's worth...

12-15-2005, 05:38 AM	#7
FatBird19 Senior Member Join Date: Jun 2005 Posts: 959	960x540? Whoa, that's low! If that's true, Panasonic had better provide a bunch of h.264 sample videos on their site cause I know that a large amount of consumers and propeller heads are going to see "960x540" and run away screaming. Myself, having seen the footage, know better. Panasonic, put lot's of samples on your site. Get some of the talented people in here to make them.

12-15-2005, 06:35 AM	#8
JitCam Senior Member Join Date: Dec 2005 Location: Crete, Greece EU Posts: 299	people please! cameras are not just resolutions.. dont get caught up only into the numbers.. there are other things wirth mentioning also.. like lense.. which plays a HUGE role in overall quality and texture. i really dont think that the HVX lacks in any way in resolution. ive gotten really good images from my sony miniDV which is a single CCD cam. i think with proper lighting and good use of codecs u can get pro looking footage from this cam.