HVX200 matched with the RED

[Phil Rhodes]

I'm being completely subjective here as the technical specs of the HVX are a matter of public record, but the images in this thread do nothing but reinforce my impression that the HVX is an entirely mediocre camera. It's soft, it's noisy, there's lens abberation all over it, ick.

 

Phil

[Mike Miller]

Thee is no resolution difference on HVX200 between its 720p and 1080p output. That means that performance-wise it is at most a 720p camera, just as Red is performance-wise a 3K, not a 4K camera.

[John Sprung]

Thee is no resolution difference on HVX200 between its 720p and 1080p output. That means that performance-wise it is at most a 720p camera, just as Red is performance-wise a 3K, not a 4K camera.

It's three chips, 540 x 960, upconverted to make both 720p and 1080i.

 

 

 

-- J.S.

[Tommy Oliver]

The thing that Panasonic did best with the HVX was marketing. Before I got a chance to play around with the camera and really dig into the specs, I was intrigued and actually considered purchasing one - I mean thing does 1080p (right?) which just two years ago was the holy grail of HD. Only it doesn't really do 1080p or 720p for that matter since it has 960x540 CCDs that must uprez to produce HD output. It's not bad for what it is but 1280x1080 output from a 960x540 CCDs does not equal real 1080p. It's not a bad camera once you realize what it actually is and how to best utilize it by shooting as close as you can to the sensor size (720p) to keep your image from becoming soft or grainy.

 

Just my $0.02.

[Adamo P Cultraro]

Which is a conundrum because the 1080 mode is sharper than the 720 mode as proven by Barry Green and countless resolution charts freely available online and still we continue to have this inane argument about whether the camera does 1080 or whether it's real 1080.

 

Some one will trot out Nyquist right away......gag me with a spoon.

[Mitch Gross]

The camera has to uprez to get to either format, but does so in different fashions. In the end, 1080 is a bit sharper, but not by much.

[Joe Taylor]

Thee is no resolution difference on HVX200 between its 720p and 1080p output. That means that performance-wise it is at most a 720p camera, just as Red is performance-wise a 3K, not a 4K camera.

 

 

REDUSER booted this "Mike Miller" hermaphrodite (and other assumed handles) for trolling the forums and talking really pathetic trash.

[John Sprung]

The camera has to uprez to get to either format, but does so in different fashions. In the end, 1080 is a bit sharper, but not by much.

How do you control out display differences, and make sure that the differency you measure really comes from the camera?

 

 

 

 

-- J.S.

[Adamo P Cultraro]

Because I own the camera, and it is obvious the 1080 setting is sharper. Besides, Barry Green has run res tests back to back and there is a clear difference.

 

Panasonic sells 2000 HVXs per month. Don't you guys think there would be general uproar if the 720/1080 modes were identical?????

[Adamo P Cultraro]

A pretty good explanation of how the HVX achieves 1080 was posted by Barry Green on DVXUser a while back. I'm not qualified to discuss it in depth; he's the local brain trust on the matter.

 

"The "pixel shift" system is not "uprezzing". Uprezzing is a digital interpolation; that's what Sony does with its V1U. "pixel shift" is not actively "shifting" anything, it merely references that one chip is spatially offset by half a pixel, which doubles the effective sampling sites (960x2 = 1920, 540x2 = 1080) to give the system a theoretical max of 1920 x 1080 sampling sites. Juan says that he gets 2K out of it because there are more active pixels on the chips; he's reading an actual 2048 x 1105 out of the system.

 

To take matters further, the "pixel shift" system isn't really all that different than a bayer pattern system. Look at the Silicon Imaging SI-2K chip -- that's a 1920x1080 chip system, right? So is it "true" 1920x1080? Well, it has a bayer filter over it, which means that 1/4 of its pixels are covered with blue, 1/4 of them are covered with red, and 1/2 are covered with green. And that means that its red and blue resolutions are (guess what): 960 x 540. Its green is better, at 960x1080-ish (but "ish" because it's not an actual 960x1080, it's a zigzag pattern of half-size 960x1080 pixels). You cannot read the system as discrete pixels, because no individual chip pixel works on its own -- each blue pixel must be used in concert with a nearby red and green pixel, for example.

 

So does that mean that the "highest resolution" you can get from an SI-2K is 960x540? Try making that claim to them and they'll laugh you out of the room. Look at the footage -- it's obviously 2K res. So how can this be? It's just the way it is.

 

And spatial offset works largely the same way, but instead of having all the pixels on one big chip, they're separated out onto three separate chips (one red, one green, one blue). And the total surface area of the three HVX 1/3" chips is about 75% as large as the total surface area of the SI-2K's single 2/3" chip.

 

You've got to divorce yourself from the mentality that "one pixel = one pixel", because it just doesn't. For example, each pixel in the target YUV frame is made up of 60% green, 29% red and about 11% blue (or thereabouts). How does that work for a 1:1 relationship? It doesn't. Because there isn't a 1:1 relationship. It's too bad that sensor designers chose the same term ("pixel") as the RGB graphic frame people did, as that just adds an unnecessary layer of confusion."

Edited December 18, 2007 by Adamo P Cultraro

[Phil Rhodes]

> which doubles the effective sampling sites

 

Obviously, it doesn't.

 

It allows you to do somewhat better than just blowing up a smaller image.

 

It does not have as extreme an effect as doubling the effective photosites.

 

Phil

[Brian Drysdale]

So does that mean that the "highest resolution" you can get from an SI-2K is 960x540? Try making that claim to them and they'll laugh you out of the room. Look at the footage -- it's obviously 2K res. So how can this be? It's just the way it is.

 

And spatial offset works largely the same way, but instead of having all the pixels on one big chip, they're separated out onto three separate chips (one red, one green, one blue). And the total surface area of the three HVX 1/3" chips is about 75% as large as the total surface area of the SI-2K's single 2/3" chip.

 

The resolution of a Bayer sensor isn't the same as the pixel count, this applies to the SI 2k the same as it applies to RED. With these cameras there's debate over the percentage (60% to 75% on the RED depending who's putting the case), but it's accepted that it's not 100%.

Edited December 18, 2007 by Brian Drysdale

[Adamo P Cultraro]

> which doubles the effective sampling sites

 

Obviously, it doesn't.

 

It allows you to do somewhat better than just blowing up a smaller image.

 

It does not have as extreme an effect as doubling the effective photosites.

 

Phil

 

 

Why doesn't it? Serious question.