Johann Adler
December 1st, 2005, 10:09 AM
Greetings everyone,
So, the HVX200's sensitivity has been stated to be F8 @ 2000 lux right? I know this isn't official, but that's pretty much what has been leaked out right now (supposedly from Panasonic themselves).
If this is correct, I did a little mathematical calculation and figured out the ballpark total pixel count of the HVX200.
It goes like this:
AJ-SDX900: 2/3" CCD with 520,000 pixels rated F13 @ 2000 lux --> 0.667/520000 = ~12.8x10^-7 pixel size (in inches)
AJ-HDC27H (Varicam): 2/3" CCD with 1,019,280 pixels rated F12 @ 2000 lux --> 0.667/1019280 = ~6.54x10^-7
Sony FW900 (CineAlta): 2/3" CCD with 2,200,000 pixels rated F10 @ 2000 lux --> 0.667/2200000 = ~3.03x10^-7
DVX-100: 1/3" CCD with 410,000 pixels rated F11 @ 2000 lux --> 0.333/410000 = ~8.13x10^-7
Ok, this information allows us to extrapolate a correlation between pixel size and sensitivity. So we divide the larger pixel size (higher sensitivity) by an unknown ratio (x) to equal the smaller pixel size (lower sensitivity)
I'll take two examples:
Panasonic Varicam (F12) and Sony CineAlta (F10)
6.54x10^-7 / x = 3.03x106-7
x = ~2.16
AJ-SDX900 (F13) and DVX-100 (F11)
12.8x10^-7 / x = 8.13x10^-7
x = 1.57
These two examples indicate that for every two stops decrease in pixel sensitivity, pixel size decreases by 1.57-2.16 times in size.
I compared the Varicam and CineAlta, because both are high end sensors with high sensitivity even compared to other sensors at equal pixel size. Sony sensors are known to be more sensitive than Panasonic sensors at the same pixel size. Likewise, the SDX900 and DVX100 comparison show us that within the Panasonic line, the pixel size need not be decreased as much for the equal two stop reduction in sensitivity. Taking these two examples in account, I conclude that on average, for every two stop reduction in sensitivity the pixel size decreases by half.
Applying this knowledge to the HVX200 reported sensitivity of F8 @ 2000 lux, we can estimate the total pixel count or gross resolution of the CCD.
Since the HVX200 fits the same nitch in HD as the DVX100 fits in SD in the Panasonic line (and thus the pixel sensitivity should be closest to each other) I will use the DVX100's pixel size as a starting point for calculating the HVX200's pixel size:
DVX100 pixel size = 8.13x10^-7 inch
HVX200 CCD size = 0.333 inch
0.333 / x # of pixels = (8.13x10^-7)/[(2)(1.5)]
Thus the HVX200's total CCD pixel count = 1,230,012
If we believe Panasonic's claims of a true 1080p CCD sensor (which I do), then we can simply divide this number by 1080 and get:
1139 X 1080 resolution of the sensor
So, taking into account the generality of the pixel size : pixel sensivity ratio, I conclude that the Panasonic HVX200 CCD pixel count or resolution is 1280 X 1080.
And guess what, I believe this number has been thrown around as a possibility based on "insider" reports or speculations. If this turns out to be true this camcorder can simply use horizontal pixel shift and generate a 1920 X 1080 resolution. Keep in mind that Sony's FX1/Z1 has 960 horizontal pixels; pixel shifted to generate 1440 non-square pixel resolution.
1440/960 = 1.5
1920/1280 = 1.5
Thus, it looks like pixel shift can be used to generate 1.5 times the resolution of the actual pixels. In my view, Panasonic is taking the purist route of actually pixel shifting to 1920 instead of 1440 (non-square).
In my opinion, this is a great step foreward for inexpensive HD camcorders. Throw in the fact that it has true progressive sensors and it will be great to see in action. Of course, F8 sensitivity isn't that great and noise will be an issue, but they have slightly improved that on the DVX100b and I'm sure they put in a cleaner gain in the HVX200 (just like Sony did with the FX1/Z1 to compensate for the reduced sensitivity/low light performance).
Happy Holidays to all,
Johann
So, the HVX200's sensitivity has been stated to be F8 @ 2000 lux right? I know this isn't official, but that's pretty much what has been leaked out right now (supposedly from Panasonic themselves).
If this is correct, I did a little mathematical calculation and figured out the ballpark total pixel count of the HVX200.
It goes like this:
AJ-SDX900: 2/3" CCD with 520,000 pixels rated F13 @ 2000 lux --> 0.667/520000 = ~12.8x10^-7 pixel size (in inches)
AJ-HDC27H (Varicam): 2/3" CCD with 1,019,280 pixels rated F12 @ 2000 lux --> 0.667/1019280 = ~6.54x10^-7
Sony FW900 (CineAlta): 2/3" CCD with 2,200,000 pixels rated F10 @ 2000 lux --> 0.667/2200000 = ~3.03x10^-7
DVX-100: 1/3" CCD with 410,000 pixels rated F11 @ 2000 lux --> 0.333/410000 = ~8.13x10^-7
Ok, this information allows us to extrapolate a correlation between pixel size and sensitivity. So we divide the larger pixel size (higher sensitivity) by an unknown ratio (x) to equal the smaller pixel size (lower sensitivity)
I'll take two examples:
Panasonic Varicam (F12) and Sony CineAlta (F10)
6.54x10^-7 / x = 3.03x106-7
x = ~2.16
AJ-SDX900 (F13) and DVX-100 (F11)
12.8x10^-7 / x = 8.13x10^-7
x = 1.57
These two examples indicate that for every two stops decrease in pixel sensitivity, pixel size decreases by 1.57-2.16 times in size.
I compared the Varicam and CineAlta, because both are high end sensors with high sensitivity even compared to other sensors at equal pixel size. Sony sensors are known to be more sensitive than Panasonic sensors at the same pixel size. Likewise, the SDX900 and DVX100 comparison show us that within the Panasonic line, the pixel size need not be decreased as much for the equal two stop reduction in sensitivity. Taking these two examples in account, I conclude that on average, for every two stop reduction in sensitivity the pixel size decreases by half.
Applying this knowledge to the HVX200 reported sensitivity of F8 @ 2000 lux, we can estimate the total pixel count or gross resolution of the CCD.
Since the HVX200 fits the same nitch in HD as the DVX100 fits in SD in the Panasonic line (and thus the pixel sensitivity should be closest to each other) I will use the DVX100's pixel size as a starting point for calculating the HVX200's pixel size:
DVX100 pixel size = 8.13x10^-7 inch
HVX200 CCD size = 0.333 inch
0.333 / x # of pixels = (8.13x10^-7)/[(2)(1.5)]
Thus the HVX200's total CCD pixel count = 1,230,012
If we believe Panasonic's claims of a true 1080p CCD sensor (which I do), then we can simply divide this number by 1080 and get:
1139 X 1080 resolution of the sensor
So, taking into account the generality of the pixel size : pixel sensivity ratio, I conclude that the Panasonic HVX200 CCD pixel count or resolution is 1280 X 1080.
And guess what, I believe this number has been thrown around as a possibility based on "insider" reports or speculations. If this turns out to be true this camcorder can simply use horizontal pixel shift and generate a 1920 X 1080 resolution. Keep in mind that Sony's FX1/Z1 has 960 horizontal pixels; pixel shifted to generate 1440 non-square pixel resolution.
1440/960 = 1.5
1920/1280 = 1.5
Thus, it looks like pixel shift can be used to generate 1.5 times the resolution of the actual pixels. In my view, Panasonic is taking the purist route of actually pixel shifting to 1920 instead of 1440 (non-square).
In my opinion, this is a great step foreward for inexpensive HD camcorders. Throw in the fact that it has true progressive sensors and it will be great to see in action. Of course, F8 sensitivity isn't that great and noise will be an issue, but they have slightly improved that on the DVX100b and I'm sure they put in a cleaner gain in the HVX200 (just like Sony did with the FX1/Z1 to compensate for the reduced sensitivity/low light performance).
Happy Holidays to all,
Johann