TECH: Native CCD Resolution OR Does Anyone Know What Time It Is?

[BobDiaz]

A man with one watch knows what time is, but a man with two watches is never quite sure. When you have a single number, the number seems correct, but when you have two or more numbers that don't agree, you have a problem deciding which is correct. What follows is a listing of the different parts to the model I've tried to create to resolve the issue as to what is the native resolution of the CCDs.


IT HAS TO BE THIS LOGIC:

This logic assumes that the camera just has the minimum amount of pixels to resolve the highest resolution. The highest necessary resolution is 1920x1080 or if you take into account the 1280x1080 recording resolution, it's a bit lower in the horizontal resolution. Assuming that everything is pushed to the limits, the Kell Factor could be as high as 0.95 and the increase in resolution due to pixel offset could be as high as 1.7; resulting in a somewhat fuzzy maximum resolution.

(0.95 Kell x 1.7 Offset Increase) = 1.615

For 1080 mode:
1920 / 1.615 = 1189 Native CCD horizontal or
1280 / 1.615 = 793 Native CCD horizontal
1080 / 1.615 = 669 Native CCD vertical

For 720 mode:
1280 / 1.615 = 793 Native CCD horizontal or
960 / 1.615 = 594 Native CCD horizontal
720 / 1.615 = 446 Native CCD vertical
​

These numbers represent the limit for the lowest native CCD resolution. A more reasonable guess would be to use a Kell in the range of 0.6 to 0.85 and an offset increase of around 1.2 to 1.5 times. I could show the calculations, but this does not prove anything.


IT HAS TO BE THIS LOGIC, FOR COLOR:

Assuming that the 4:2:2 has enough color pixels to fully resolve this ratio, we find that for 1920x1080, 1/2 of 1920 = 960 pixels in the horizontal direction. On the other hand, the maximum recording resolution is 1280h, so 640 pixels will cover this nicely. I think that it's a safe bet than the native CCDs are greater than 640 pixels in the horizontal direction.

As for the vertical direction, some have suggested that the vertical native resolution is 1080. While I can't fully rule this out, 780h x 1080v is possible, it seems a stretch. A native resolution of 720v is also possible.

Before someone starts throwing rocks at Panasonic, remember this is ONLY SPECULATION on my part and NOT fact. If I am correct, remember that 1080 4:2:0 would have 540 color samples in the vertical direction. Any number of color pixels greater than 540 is better than 4:2:0.

An interesting experiment would be to take the JVC, Canon, Panasonic, and a Blue object in front of a Green Screen. First take the component output of the JVC and record it into the Panasonic at 720p. Now record the Panasonic in the same 720p mode. Do the vertical color edges look the same between the two clips? If the look about the same, we know that the vertical native resolution is at least 720 in the Panasonic.

Likewise, do the same with the component output of the Canon into the Panasonic recording 1080i mode. Now compare that to the Panasonic camera's recording at 1080i. Do the vertical color edges look the same between the two cameras? If the Panasonic looks worse, we know that the vertical native resolution is less than 1080.

Until someone does this experiment, I can only guess at what the results might be. However, if someone does it, I'm sure we'd all be interested in the results.


CCD SENSITIVITY:

As the surface area of a single CCD cell increases, so does the sensitivity of the cell. If you double the area, you double the sensitivity. "IN THEORY", one should be able to look at the relative sensitivity of each CCD and have a rough idea of the number of pixels.

The Effective ISO rating is found in Adam Wilt write-up.

See: http://www.dv.com

Canon XL-H1 200 ISO (1440x1080=1,555,200 pixels)
JVC GY-HD100 Just under 320 ISO (1280x720=921,600 pixels)
Panasonic AG-HVX200 320 ISO (???x???=???,??? pixels)
Panasonic AG-DVX100B 500 ISO (770x492=378,840 pixels) The DVX-100B was not reviewed by Adam, but I added it to the list for comparison.
Sony HVR-Z1 200 ISO (960x540=518,400 pixels) I Corrected for shutter speed difference in the Sony.

If we take the Canon's resolution and ISO and compare it to the Panasonic's ISO, we get a ratio of: 1,555,200 pixels x (200 ISO / 320 ISO) = 972,001 pixels. This looks VERY close to, but a bit higher than the number of pixels on the JVC.

Using JVC's resolution and ISO, we come up with a native resolution slightly LOWER than the 1280x720 resolution of the JVC.

Using the Panasonic DVX-100B for comparison, we get: 378,840 pixels x (500 ISO / 320 ISO) = 591,938 pixels.

If I compare to the Sony, the numbers don't make any sense: 518,400 pixels x (200 ISO / 320 ISO) = 324,000 pixels. A 720x480 CCD has 345,600 pixels. I can only assume that the Sony used an older CCD that was not as sensitive to light as the current CCDs.

Using this type of logic, the native pixel count could be from 972,001 pixels to 591,938 pixels. If we assume a vertical resolution of 720, the native resolution would range from 1350x720 to 822x720. I'm not saying that it would be those exact numbers, but could be something around that range.

BEFORE anyone starts saying that this IS the resolution, remember that CCD sensitivity varies a great deal and surface area of the pixel is only one of several factors that effect the sensitivity. This part of the model, can only give us a very rough idea of the range.


SINGLE OR DUAL A/D (Analog to Digital):

We know that JVC had to use dual A/D converters, because 1280x720 was just too many pixels to transfer from the chip in serial. That came to 921,600 pixels per 1/60 of a second. Splitting the CCD into a left and right side allowed for a slower shift clock, but required dual A/D converters.

Canon, as far as I know, was able to do this with a single A/D converter. Thus, with 777,600 pixels per 1/60 of a second, a single A/D Converter per CCD is possible, but with 921,600 pixels in 1/60, a dual A/D Converters are required. The maximum number of pixels BEFORE one must use dual A/D Converters is unknown.

This suggests that the number of pixels on the Panasonic CCD is likely to be less than 921,600 pixels. Maybe Panasonic did have 921,600 pixels and found a better way to transfer the data from the CCD.

IF we assume that the number of pixels is exactly 777,600 pixels, and the vertical resolution is 720, the Native CCD Resolution would be 1080x720. This is just an example and should NOT be taken as an exact number.

What this part of the model does suggest is that the upper end for the Native Mode Resolution can NOT be 1350x720 or even 1280x720, but the lower end of the CCD Sensitivity might be possible. Thus, something around 1080x720, 1024x768, or 960x810 may be reasonably close to the Native Resolution.


AIRY DISK MEASUREMENT:

My thanks to the Masked Engineer a well-known television engineer who wishes to remain anonymous for pointing this one out:

http://www.tvtechnology.com/features/Masked-Engineer/f_mario_orazio-08.17.05.shtml


In theory, the following constants should be applied to the following colors:

Red = 3613
Green = 4661
Blue = 4791

Color Constant / F Stop = Maximum Lines Of Resolution
​

We know that the HVX-200 holds the resolution to F8 and at F9.6 the resolution starts to drop. Thus, 4461 / 8 = 558 lines, right? No, WRONG!!!!

If this logic is correct, than the JVC's resolution should take a major hit when tested at F16. A French WEB page reported 550 lines, but the calculation says, 4791 (Blue) / F16 = 299 lines. Clearly, the logic is flawed.

The Airy Disk does NOT have a hard edge, so we would need to test cameras like Canon and JVC where we know the CCD resolution at different F Stops to see the impact of the Airy Disk and THEN compare to the Panasonic.

More tests would need to be performed before I can even begin to use the Airy Disk as part of the model.


RESOLUTION CHARTS:

Depending on how you want to read the resolution charts, the numbers range from 700h to 550h and 750v to 540v. The range of numbers can drive you absolutely nuts. Just assume that the correct resolution is 600h and 600v. This is not he lowest number, but is within 50 to 60 lines of the lower numbers. This translates to 600/700 of JVC's Resolution of 1280x720 or an effective resolution of 1097x617.

Taking into account the pixel shift and the difference could range between 1.2x to 1.5x increase in resolution. This would take our 1097x617 effective resolution and make the native range from 731x411 to 914x514. These numbers seem way too low to make sense. IF they were correct, going from 720 mode to 1080 mode would offer no real increase in resolution.

At the high end of the scale, the numbers are 700h x 750v. This would be an equivalent resolution of 1280x771. With a native resolution ranging from 853x514 to 1067x643. The resolution 1024x576 seems like a good number using this logic.

The flaw is this part of the model is the numbers vary too much AND we must assume that the CCD is the limiting factor for the resolution. Given that the Canon's maximum is around 800v lines, when the CCD should go to around 1000, this suggests that the lens could be the limiting factor.


CONCLUSION:

If you take only one part from this model and use it to obtain an answer, you ignore all the other parts and fool yourself into thinking you know the answer. My wife knows the answer to, "What time is it?" Several year back, when our watches didn't agree, she told me mine was wrong. When I pointed out that I check my watch every month to the National Bureau OF Standards WWV's Time Signal, she told me, "They're wrong too!" Maybe I should ask her what the Native CCD Resolution is... :cheesy:


Bob Diaz

 

[Mr. Blonde]

Wow Bob, you make me feel like a peon in mathamatics, very interesting read, thanks!

 

[MarcusX]

Once again, great post Bob.

But you don't need a lot of math to find out what the native CCD resolution is.

What you need:

- HVX200
- saw (hammer might do it as well)
- BIG magnify glass (better: microscope)
- pen and paper

OR (if you don't have the HVX200 yet)

- flightticket to japan, home of panasonic
- english - japanese / japanese - english translator
- a gun (hammer might do it as well)
- location of one of the HVX200 engineers :cheesy:

 

[Barry_Green]

An interesting experiment would be to take the JVC, Canon, Panasonic, and a Blue object in front of a Green Screen. First take the component output of the JVC and record it into the Panasonic at 720p. Now record the Panasonic in the same 720p mode. Do the vertical color edges look the same between the two clips? If the look about the same, we know that the vertical native resolution is at least 720 in the Panasonic.

Likewise, do the same with the component output of the Canon into the Panasonic recording 1080i mode. Now compare that to the Panasonic camera's recording at 1080i. Do the vertical color edges look the same between the two cameras? If the Panasonic looks worse, we know that the vertical native resolution is less than 1080.

But you can't do this. The cameras don't have component inputs. It would make for an interesting test, but it's not possible.

If I compare to the Sony, the numbers don't make any sense: 518,400 pixels x (200 ISO / 320 ISO) = 324,000 pixels. A 720x480 CCD has 345,600 pixels. I can only assume that the Sony used an older CCD that was not as sensitive to light as the current CCDs.

Ah, but there's the rub -- the Sony is NOTICEABLY quieter in noise than the others. So you could look at it one of two ways -- either they chose to lower the sensitivity artificially to suppress noise, or everyone else raised their sensitivity and accepted the increase in noise that comes with it. The noise levels on the other three (JVC, Panasonic & Canon) are all within spittin' distance of each other, but the Sony is noticeably quieter. You'd have to factor that into your equation to make your model work.

know that JVC had to use dual A/D converters, because 1280x720 was just too many pixels to transfer from the chip in serial. That came to 921,600 pixels per 1/60 of a second. Splitting the CCD into a left and right side allowed for a slower shift clock, but required dual A/D converters.

Canon, as far as I know, was able to do this with a single A/D converter.

Canon uses an interlaced chip though, so they also "split it in half" (vertically, every other line); they only have to read off half the chip per 60Hz interval. The JVC and the Panasonic both use a 60P chip, which requires the entire thing to be read off per 60Hz interval.

Because of this, again I would not be surprised to find out that the Panasonic's chip count is lower, and it makes up the resolution difference through its spatial offset. If they used the same high-density pixel count as JVC did, they'd probably end up with the same split-screen situation.

731x411 to 914x514 on the low end; 853x514 to 1067x643 on the high end.

The math is fascinating. I mean, you're laying out a case where they could be getting the resolution they're getting with a pixel count as low as 731x411! Which sounds silly, but we also know Juan Pertierr of reel-stream/Andromeda is getting 1540x984 pictures out of a DVX's chipset, and that's 770x492. And it looks good. So... hmmm. Interesting.

Around a year ago I wrote up a massive missive (mr. alliteration at it again!) laying out how I thought that they'd be 960x720. I've always thought that the chips would be 960 wide. Any more doesn't make any sense to me, because 960 can easily pixel-shift to at least 1280, and the two recording formats it records are 960 wide or 1280 wide. But we also know that they're using vertical pixel shift too, but the recorded vertical res isn't any higher for 1080 vs. 720. Don't know what that says for the numbers, but again it makes sense since the 1/3" cameras will be diffraction-limited to around 800 lines anyway. So I wonder if it even needs to be 720, since they are using vertical spatial offset? It seems reasonable that it could be lower than 720 and still work, and in your four potential scenarios that you laid out, they're all less than 720. Hmmm.

So frankly I wouldn't be surprised if your numbers end up being about right.

It's all academic until Panasonic releases the chip count, and even then I still say it's pretty much irrelevant, because the camera is still putting out a high-def image that looks sharp as a tack on real-world footage. The definition and res increase over the DVX is amazing.

 

[limo991]

As Barry mentioned there is the gain factor also. Gain is usually implemented with an offset. The real gain can be anything. analog or digital. Any offset. Even arbitrary values represented on the user interface in "dbs". Is an AD that outputs digital max at 3volts better than one that does the same with 6 volts if the digitally boosted lower amplitude digital signal is cleaner? It all depends on the quality of the output. It is a fact that the FX1 is a lot better in low light compared to a VX2000 although FX1 is "less sensitive". The FX1 gain is very clean and that only shows the 0 db point is set conservatively on the fx1 controls. The real test is to setup low light scenes, get similar exposure in all cameras at exact apperture and shutter at ANY gain control setting required. And compare the results for noise, shadow detail and quality of image. This is what we do in the real world. We go for an exposure. We get it. All we need to know is which camera is cleaner at that exposure. The actual gain setting is only important if we reach the limits of exposure and we can't go further.
A Nikon D50 produces much brighter images at same ISO setting with my EOS 350D. Not very ISO after all Nikon's ISO200 is similar to canon's ISO100 for these cameras. Is it important? Not really. But it could sell some cameras for Nikon. Nikon ISO1600 and Canon ISO800 get me similar shutter for similar exposure so ISO setting (or gain setting) is not important for me.

A Bob metioned, pixel size follows an exact law only in theory. Even when comparing chips from the same manufacturer and the same product line it's not very precise. It depends on the fill factor, the support circuitry and numerous other parameters. A 3CCD camera could have higher quality filters in its optics that block the spectrum a lot better but lose more light. A cheaper prism would lose light also. Bigger (less) pixels and smaller sensitivity.

I'm not even sure these cameras have the same sensor size. The optical format 1/3inch rating could vary a lot.

 

[limo991]

Once again, great post Bob.

But you don't need a lot of math to find out what the native CCD resolution is.

What you need:

- HVX200
- saw (hammer might do it as well)
- BIG magnify glass (better: microscope)
- pen and paper

OR (if you don't have the HVX200 yet)

- flightticket to japan, home of panasonic
- english - japanese / japanese - english translator
- a gun (hammer might do it as well)
- location of one of the HVX200 engineers :cheesy:

I believe no form of threat or torture could make a Panasonic engineer release the sensor specs at this time.

 

[BobDiaz]

But you can't do this. The cameras don't have component inputs. It would make for an interesting test, but it's not possible.

Rats!!! :undecided

Maybe we could feed the signals to a high end HDTV monitor and use a digital camera to look at the signals or the capture board that was used in your 6 camera
test. This would be A LOT of work and my guess is it's not worth all the trouble.

It would be interesting to put a green filter in front of the HVX that only allows green light to pass. Then measure resolution with and without the filter. This would tell us how much resolution we gain with the pixel offset.

Ah, but there's the rub -- the Sony is NOTICEABLY quieter in noise than the others. So you could look at it one of two ways -- either they chose to lower the sensitivity artificially to suppress noise, or everyone else raised their sensitivity and accepted the increase in noise that comes with it. The noise levels on the other three (JVC, Panasonic & Canon) are all within spittin' distance of each other, but the Sony is noticeably quieter. You'd have to factor that into your equation to make your model work.

I knew there had to be a reason, but forgot about noise level. Let's just ignore the Sony as part of the model. That places the native CCD resolution in the neighborhood of around 972,001 pixels (too high) to 591,938 pixels. If I use the lower number and assume the vertical is 720 pixels, the answer is 822x720. It would be within reason to expect a native resolution of 960x720.

Canon uses an interlaced chip though, so they also "split it in half" (vertically, every other line); they only have to read off half the chip per 60Hz interval. The JVC and the Panasonic both use a 60P chip, which requires the entire thing to be read off per 60Hz interval.

Because of this, again I would not be surprised to find out that the Panasonic's chip count is lower, and it makes up the resolution difference through its spatial offset. If they used the same high-density pixel count as JVC did, they'd probably end up with the same split-screen situation.

My calculation for Canon is 1440h x 1080v / 2 (for interlace) = 777,600 pixels per pass or 777,600 pixels in 1/60 of a second. We know that the Panasonic is unlikely to be as high as the JVC's pixel rate, BUT the 777,600 pixels in 1/60 of a second IS possible. Assume that the native pixel count was 777,600 pixels, 960x810 would be possible.

The math is fascinating. I mean, you're laying out a case where they could be getting the resolution they're getting with a pixel count as low as 731x411! Which sounds silly, but we also know Juan Pertierr of reel-stream/Andromeda is getting 1540x984 pictures out of a DVX's chipset, and that's 770x492. And it looks good. So... hmmm. Interesting.

I hope that everyone understands that when doing these calculations, you can end up with numbers that are just plain stupid. The danger is someone could lock onto one part of the model and come up with an answer that is VERY far from the correct answer. All the parts need to be considered to even hope to get close to the answer.

The 770x492 is possible for the HVX-200, but with 378,840 pixels, either the ISO should be higher or the noise level should be lower. Then again, maybe there's some unknown factor...

Around a year ago I wrote up a massive missive (mr. alliteration at it again!) laying out how I thought that they'd be 960x720. I've always thought that the chips would be 960 wide. Any more doesn't make any sense to me, because 960 can easily pixel-shift to at least 1280, and the two recording formats it records are 960 wide or 1280 wide. But we also know that they're using vertical pixel shift too, but the recorded vertical res isn't any higher for 1080 vs. 720. Don't know what that says for the numbers, but again it makes sense since the 1/3" cameras will be diffraction-limited to around 800 lines anyway. So I wonder if it even needs to be 720, since they are using vertical spatial offset? It seems reasonable that it could be lower than 720 and still work, and in your four potential scenarios that you laid out, they're all less than 720. Hmmm.

If the vertical native resolution of the CCDs was 540, there would be no difference in color resolution in the vertical direction between Panasonic's 4:2:2 and Canon's 4:2:0. I like your 960x720, because the 960 is easy to convert in the horizontal and the 720 provides true 4:2:2 in the vertical in 720p mode. OK, in the 1080 mode, the 4:2:2 works out to only 75% of the color pixels in the vertical, BUT that's better than 50% of the color pixels for 4:2:0. The total pixel count of 691,200 would be within the single A/D limit, so it is possible....

So frankly I wouldn't be surprised if your numbers end up being about right.

It's all academic until Panasonic releases the chip count, and even then I still say it's pretty much irrelevant, because the camera is still putting out a high-def image that looks sharp as a tack on real-world footage. The definition and res increase over the DVX is amazing.

No question that if it looks good, so what, but let me respond to those who say, "WHO CARES, AS LONG AS IT LOOKS GOOD!!! BESIDES, IF YOU SPEND ALL YOUR TIME THINKING ABOUT THIS, YOU HAVE NO LIFE!!!"

Well, I am an engineer, so I have NO life. Engineers by their very nature can't help it. Take Rubik's Cube, it turns out that the best solution for dealing with that problem is a 357 magnum; see, problem solved. I'm not suggesting that this solution be used in dealing with native CCD Resolution, but it does show that at times, creative solutions can be very satisfying. :laugh:



OTHER POST:

But you don't need a lot of math to find out what the native CCD resolution is.

What you need:

- HVX200
- saw (hammer might do it as well)
- BIG magnify glass (better: microscope)
- pen and paper

OR (if you don't have the HVX200 yet)

- flightticket to japan, home of panasonic
- english - japanese / japanese - english translator
- a gun (hammer might do it as well)
- location of one of the HVX200 engineers

When I worked for Epson America, we purchsed other companies products to tear them apart to see how they worked. It was a lot of fun to see a $3,000 laptop torn into a zillion pieces. I strongly believe that JVC, Canon, and Sony have ripped their HVX-200s into a zillion pieces and they know what the Native CCD Resoluition is... BUT, it's like an unwritten rule, everyone does it, but no one admits to knowing anything about doing it.

Some day, some unlucky person is going to accidently break their HVX-200 beyond repair. At that point, we can only hope that he/she knows someone who will tear into the camera and see what the native CCD resolution is.

I did have a dream that I was opening an HVX-200 and looking inside. However, when I saw a vacuum tube inside the camera, I was so busy trying to figure that one out, I forgot to look at the CCDs. On the other hand, maybe we could start an ugly rumor that the HVX-200 uses a vacuum tube!!! :evil:



Bob Diaz

 

[BobDiaz]

>>>>>> Update <<<<<

>>>>>> Update <<<<<

CCD SIZES:

In trying to find the CCD size to factor in the difference for CCD dimensions, I found the size for the JVC's CCD, but not Canon's or Panasonic. However, there is a way to estimate the size of Canon's and Panasonic's CCDs within 1% or 2%.

JVC's CCD = 4.864mm x 2.739mm
Conversion from video lens to equivalent 35mm camera = 7.75x

Canon's CCD =1.076(4.864mm x 2.739mm)= 5.234mm x 2.947mm
Conversion from video lens to equivalent 35mm camera = 7.20x
(7.75 / 7.20 = 1.076)

Panasonic's CCD = 1.0078(4.864mm x 2.739mm)= 4.902mm x 2.760
Conversion from video lens to equivalent 35mm camera = 7.69x
(7.75 / 7.69 = 1.0078)

While I show the calculations to 4 places, I think the accuracy is only good to 2 places. Still, an important fact comes out of this; if I compare the size of the Panasonic's CCD to the size of Canon's CCD, we see that the Panasonic is 0.936 of the Canon. Now take Canon's 800- lines x 0.936 = about 749- lines. In other words, if we shrink the Canon's CCD to the smaller size CCD found on the Panasonic, we would expect to see around 750- lines of resolution. The limit appears to be due to both the lens and the smaller CCD size of the Panasonic.


CCD SENSITIVITY:

When I compare the JVC's to the Canon's CCD sensitivity, the results come within a few percent. While very tempting to use this logic, the numbers could have come close by dumb luck.

Likely the 0dB Gain points on the cameras are within 1 or 2 dB of each other's cameras, but the Sony proves that it can be way off. I believe that Barry reported that the noise levels of the Canon, JVC, and Panasonic were close to each other, but even so this is hard to tell. I think he said the Panasonic was a little less.

Assume that gain, light loses, and any other unknown result in a drop of the pixel count from the estimated value of -25%:

JVC = 921,600 pixels / 1.0078 = 914,467 Panasonic estimate

Canon = (1440 x 1080) x (200 ISO / 320 ISO) x 0.936 = 909,792 Panasonic estimate

I pick the lower number, 909,792 x 0.75 = 682,344. This is very close to 960h x 720v = 691,200.


THE CONVERSION FACTOR & THE WHOLE MODEL:

Resolution Conversion turns out to be the most important factor to consider in the model. It was yesterday when I realized how important this point is to the model. First, not every group of pixels converts quickly and easily to the required number of pixels.

Take a number like 1024; I wish to convert 1024 pixels to 1920 pixels. The notation used is 8 --> 15. Every 8 pixels must be expanded to 15 pixels. Another possible way is 1 --> 2, 16 --> 15. One pixel is converted into two and 16 pixels are converted into 15 pixels. Yes the conversion can be done, BUT it's not quick and clean.

Some quick and clean conversions are: 1 -->2, 2 --> 1, 2 --> 3, 3 --> 2, 3 --> 4, and 4 --> 3. Other conversions are possible, but as we move to higher numbers, the process becomes a bit messy with the end result. We know that the output must be 1920 x 1080, so which resolutions can convert to this result cleanly and easily?

In the horizontal direction, 720, 960, and 1280 fit the requirement of easy and clean conversion. The highest resolution, 1280 makes no sense; we have pixels that will never be seen. The lowest resolution, 720 might work, but it just doesn't seem to fit the model very well. It MAY be possible, but seems unlikely. The middle resolution, 960 makes the most sense. I believe that 960 is the native resolution in the horizontal direction.

In the vertical direction, 540, 720, and 810 fit the requirement of easy and clean conversion. I can't fully rule out 540, but it seems VERY unlikely. BOTH 720, and 810 seem to fit the model. Above 810, like 1080 is VERY unlikely. The 720 resolution seems to fit the model a little better, but 810 would work.

Remember this is only a best guess and my model may contain hidden flaws. Still the likely resolutions are:

960h x 720v Most Likely
960h x 810v Still Possible
​

I know that many on this forum obsess over resolution, but resolution is NOT the only parameter that creates a good image. If these numbers are correct, they represent a balance between ALL the different parameters that create a good image.


Bob Diaz