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-   -   EX and HVX200 (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/108098-ex-hvx200.html)

Thomas Smet November 19th, 2007 12:09 AM

Since when has HDCAM been non native resolution???

The F900 uses 1920x1080 chips the last time I checked and I composited footage from the F900. It was the tape format that used 1440x1080 not the chips.

The Varicam also used native chips of 1280x720 pixels. Again it was the tape format that used 960x720 pixels not the chips themselves.

Sure XDCAMHD uses pixel shift but the chips already have 1440x1080 pixels so they already have the native resolution of the recording format and they only need to get pushed a little bit further to get to 1920x1080 for SDI output. So when you are talkign about recording to disc the pixel shift is only being used for enhancing the detail not creating new detail.

Daniel Weber November 19th, 2007 12:09 AM

I think that a bigger advantage of the EX1 is the 1/2" chips. That and native 1920x1080 chips and a real lens are the reason that I placed my order.

We can argue specs all we want, but what I care about is how does the camera feel in my hand when I am shooting and does it allow me to do my job the best I can.

Daniel Weber

Mike Marriage November 19th, 2007 03:27 AM

Quote:

Originally Posted by Daniel Weber (Post 777797)
We can argue specs all we want, but what I care about is how does the camera feel in my hand when I am shooting and does it allow me to do my job the best I can.

Totally agree and also rate issues like reliability and work flow as far more important than native pixel count. Picture wise, low-light ability is more useful to me than being able to resolve flea's whiskers.

Good SD looks fine on massive screens, it is only when you salivate over side-by-side comparisons that all of a sudden people start calling fantastic cameras useless.

Resolution isn't really that important to a layman once you get beyond a certain level (which all of these cameras surpass). Therefore, I can see Panasonic's reasoning in using pixel shift.

However, if the EX1 can still excel in other areas such as low-light and latitude without pixel-shift, then I have no opposition to the extra resolution.

I also think that the more efficient "long GOP" codec of the EX1 is a big advantage and makes a solid state workflow 3 times more attractive. A 16GB SxS card in an EX will store as much footage as a 48GB P2 card in an HVX

Chris Hurd November 19th, 2007 08:53 AM

Quote:

Originally Posted by Gabe Strong (Post 777791)
I was saying higher NATIVE resolution, and possibly using the term 'native' in error.

Sorry for misreading you, Gabe... I'm not sure there's really any proper way to use the term "native" in this case since we'd have to know native to what, exactly. I regret the misunderstanding.

Quote:

Originally Posted by Craig Seeman (Post 777793)
It depends on how the chip is designed.

Thanks for pointing that out -- there are so many variables involved in this equation other than Pixel Shift so I don't think anybody can point to spatial offset (or any other kind of resolution booster) and single it out for better or for worse. My only point all along is that it's there for a reason and it works.

Quote:

Originally Posted by Thomas Smet (Post 777796)
Since when has HDCAM been non native resolution? The F900 uses 1920x1080 chips the last time I checked

As do the HDW790 and HDW730... apparently the "since when" goes back to the HDW700. I appreciate the correction.

Quote:

Sure XDCAMHD uses pixel shift but the chips already have 1440x1080 pixels
As do the chips in the Canon XL and XH lines; my point is that regardless of the number of pixels on the chip, they're still using H-axis Pixel Shift and it's there for a reason.

Quote:

Originally Posted by Mike Marriage (Post 777838)
... issues like reliability and work flow as far more important than native pixel count.

Fully agreed, and I apologize for the lengthy departure into spatial offset.

Kevin Shaw November 19th, 2007 09:18 AM

Looking at the results of the Texas HD shootout, it seemed to me those present felt the GOP-based cameras worked fine for handling motion when viewing video as video, and that you could only really tell a difference when pausing on still frames. And even there I can say from personal experience that if you use a high shutter speed on an HDV camera you can get clear still frames of action events like a tennis match, which is where I tested this. Since the EX1 should handle motion at least a little better than HDV it ought to be fine for most action/sports purposes, with images that look great when viewed as video.

Regarding pixel shifting, I've yet to hear of any video camera which yields greater perceivable resolution (in TVl/ph) than the number of physical pixels on its sensor. That showed in the Texas HD shootout, so I'm not sure why Chris seems to think pixel shifting works. It's just hardware-based upscaling as far as I can tell.

Chris Hurd November 19th, 2007 09:54 AM

Quote:

Originally Posted by Kevin Shaw (Post 777937)
I'm not sure why Chris seems to think pixel shifting works.

Well I'm not the only one who seems to think pixel shifting works. Apparently the engineering and design teams of nearly every major CCD manufacturer on the planet seem to think so too. Look, if spatial offset didn't work, then it wouldn't be such an integral part of almost every three-chip camera system ever made. Like I said -- it's there for a reason.

David Heath November 19th, 2007 10:35 AM

Quote:

Originally Posted by Chris Hurd (Post 777955)
Well I'm not the only one who seems to think pixel shifting works. Apparently the engineering and design teams of nearly every major CCD manufacturer on the planet seem to think so too.

It does bring benefits, it does work, no doubt.

BUT I'm concerned that a belief has unfortunately arisen among some that it is a magic bullet - "pixel shift will cure everything". And that is not true. The best write up on the subject I've seen is from Panasonic - ftp://ftp.panasonic.com/pub/Panasoni...200.CCD-WP.pdf - who claim that it will enhance native luminance resolutions by 1.5x. Though they do admit this to be a best case scenario, and more independent studies generally talk of 1.2-1.3x to maintain a decent mtf.

They claim an "effective" resolution for the HVX of up to 1440x810 (though admit that to be a best case scenario) - I'd reckon around 1200x675 to be nearer the mark, though it depends at what mtf measurement you call it a day.

Consequently, pixel shift does work - it does give an improvement over the results if it wasn't used - but let's all be realistic. Even Panasonic don't claim it will achieve anything like 1920x1080 from the HVX chipset.

Chris Hurd November 19th, 2007 11:16 AM

Quote:

Originally Posted by David Heath (Post 777978)
BUT I'm concerned that a belief has unfortunately arisen among some that it is a magic bullet - "pixel shift will cure everything".

No, no, no. I certainly hope I'm not giving that kind of impression. My long-standing annoyance has only been with those who have argued out of ignorance that Pixel Shift and the spatial offset process is some kind of gimmick, or worse, some sort of "marketing trick." It's neither. It's real, it works and it's there for a reason... but the technology is well over a decade old, and there are newer and perhaps better ways to boost resolution, as we've seen from Sony's ClearVid interpolation process.

I think we're eventually going to see an increasing rate of change to single-chip designs in the pro video market (as already clearly evident within the realm of Ultra-High Definition digital cinema acquisition systems, and as already happened long ago with digital still photography), so why should it even matter anymore.

Steven Thomas November 19th, 2007 11:24 AM

Quote:

Originally Posted by Chris Hurd (Post 777955)
Well I'm not the only one who seems to think pixel shifting works. Apparently the engineering and design teams of nearly every major CCD manufacturer on the planet seem to think so too.

Well, looking at the AG-HPX500, it sure seems to be working well.
I think part of this problem is a lot if us (including myself at time. LOL),
are comparing the "higher" native cams against the HVX200.

My understanding (and from some stuff I've seen) the HPX500 sure looks like its capable of producing some detailed clean images.

Kevin Shaw November 19th, 2007 11:37 AM

Quote:

Originally Posted by Chris Hurd (Post 778002)
My long-standing annoyance has only been with those who have argued out of ignorance that Pixel Shift and the spatial offset process is some kind of gimmick, or worse, some sort of "marketing trick." It's neither. It's real, it works and it's there for a reason...

But the results of the Texas shootout showed that pixel shifting doesn't succeed at increasing the useful resolution of a camera, so what's the practical benefit to users compared to capturing at the native sensor resolution and upscaling later?

Chris Hurd November 19th, 2007 11:42 AM

The other practical benefits are increased sensitivity (as previously explained) plus a lower manufacturing cost per CCD (which leads to greater availability and a less expensive camera). Resolution isn't everything... a fundamental concept to grasp.

Kevin Shaw November 19th, 2007 11:52 AM

Quote:

Originally Posted by Chris Hurd (Post 778022)
Resolution isn't everything... a fundamental concept to grasp.

Of course not, but you haven't said how pixel shifting in the camera is beneficial compared to upscaling sensor data in post. I won't say more about this because you obviously feel strongly about it, but it sure seems like pixel shifting is mainly useful for marketing purposes.

Chris Hurd November 19th, 2007 12:11 PM

Why do it in post when it can be done in the camera.

If spatial offset technology was "mainly useful for marketing purposes," then Panasonic would simply have announced the HVX200 as using double axis Pixel Shift right from the very beginning instead of keeping it a secret for so long. If it's there just "for marketing" then why don't Canon and Sony make a bigger marketing splash with it and inform more customers that H-axis Pixel Shift is used in the entire Sony XDCAM HD line and XL and XH series Canon camcorders? Why is it hardly ever mentioned by Sony, despite having used spatial offset for years in their full range of DVCAM and HDV camcorders?

JVC has been the only company I'm aware recently to make a point of mentioning spatial offset in their Everio camcorder product marketing (Panasonic doesn't count; they had to be prodded into disclosing their HVX200 specs).

The notion that Pixel Shift is mainly useful for "marketing purposes" is totally absurd, considering how seldom it's ever referred to in product marketing material. Prior to JVC, the only time I've ever seen it "marketed" was for the original Canon XL1 back in 1997 (despite the fact that all three-chip Canon camcorders to follow have used it in one form or another).

What I feel strongly about is the ludicrous notion that an integral component of three-chip camera design is there "just for marketing." I can hear engineers groaning over that nonsense all the way from Japan.

David Heath November 19th, 2007 12:15 PM

Quote:

Originally Posted by Kevin Shaw (Post 778028)
Of course not, but you haven't said how pixel shifting in the camera is beneficial compared to upscaling sensor data in post.

The diagram in the Panasonic paper gives a good description - though it's important to realise that the process works less well if the image is saturated in colour. Fundamentally, it enhances luminance resolution only - but since colour is normally subsampled, this shouldn't matter.

It relies on the green pixels being spatially offset from red and blue, simple upscaling assumes r,g,b to represent the same point.
Quote:

I won't say more about this because you obviously feel strongly about it, but it sure seems like pixel shifting is mainly useful for marketing purposes.
Hmmm, well, here we're back to the "magic bullet" statements, aren't we? I won't disagree that it's benefits have been overstated in the past, whether by ignorance or design I wouldn't like to speculate. But that is not the same as saying it is of no use at all. (Chris - you weren't in my mind when I made the "magic bullet" comment.)

Returning to the Panasonic link, it's also worth noting one reason WHY they give for using pixel shift.
Quote:

Knowing that the camera needed to do SD and HD, Panasonic surveyed the technologies and their respective “trade-offs”. If we used a 1/3" native resolution 1920 x1080 CCD, it wouldn’t have enough sensitivity to be practical in low light because the pixels would be too small to collect sufficient light.
Well - the answers simple when you know it, isn't it? Just use 1/2" sensors!!! The trick is then building the lens and camera small enough!

Kevin Shaw November 19th, 2007 12:16 PM

Quote:

Originally Posted by Chris Hurd (Post 778043)
The notion that Pixel Shift is mainly useful for "marketing purposes" is totally absurd, considering how seldom it's ever referred to in product marketing material.

It's mentioned all the time in the form of the advertised recording resolutions of the cameras. 'Nuff said before I get censored.


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