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I notice that Panasonic is coming out with a video camera, the PV-GS400,
that is capable of taking 4 megapixel stills. Normally the still capability
of video cameras is pretty poor due to the tiny ccd sizes, but the area of
this sensor is pretty large. I think it must be close to a 5/8 ccd in total
area. Does anybody think that this camera has the potential to produce an
image as good as a 4 megapixel digital camera with a similar sized ccd? How
many pixels would this sensor have? Is the image interpolated? What is pixel
shifting?

Wayne

"Wayne J" <> wrote in message
news:aDWEc.84527$. ..
> I notice that Panasonic is coming out with a video camera, the PV-GS400,
> that is capable of taking 4 megapixel stills. Normally the still
capability
> of video cameras is pretty poor due to the tiny ccd sizes, but the area of
> this sensor is pretty large.

I always thought the still quality had nothing to do with the size of the
sensor but instead the type pf sensor (vs. a digital still sensor) and the
quality of the lens.

Wayne J wrote:
>
> I notice that Panasonic is coming out with a video camera, the PV-GS400,
> that is capable of taking 4 megapixel stills. Normally the still capability
> of video cameras is pretty poor due to the tiny ccd sizes, but the area of
> this sensor is pretty large. I think it must be close to a 5/8 ccd in total
> area. Does anybody think that this camera has the potential to produce an
> image as good as a 4 megapixel digital camera with a similar sized ccd? How
> many pixels would this sensor have? Is the image interpolated? What is pixel
> shifting?

Panasonic and others (Canon) have already used "pixel shift technology"
before in their camcorders. This is a HOAX similar to the color mosaic
technology used in digital photography. It does NOT produce decent
true-color images, regardless of the fake Megapixel count!

"Pixel shift" shifts one CCD (usually the green) by half a pixel in both
dimensions so that pixels partially overlap and count increases by 2x2.
A "pixel shift" image looks horrible in this faked blown-up resolution,
it gets halfway acceptable if reducing both dimensions by 50% so that
the result approaches the true information contents. Such reduced
pixel-shift image looks MUCH better than any (Bayer) mosaic image
from a digital still camera, but it does not come close to a decent
true-color image as captured with a Foveon sensor, for example.

Regards
Guido

> "Pixel shift" shifts one CCD (usually the green) by half a pixel in both
> dimensions so that pixels partially overlap and count increases by 2x2.
> A "pixel shift" image looks horrible in this faked blown-up resolution,
> it gets halfway acceptable if reducing both dimensions by 50% so that
> the result approaches the true information contents.

BTW, this would compare to a 1 Megapixel true-color image and suggests
that Panasonic uses 1 Meg CCD chips, same size as used by Sony in their
actual consumer/prosumer 3ccd camcorder line. Sony do not use the
pixel-shift hoax and output a true 1-Megapixel image (which is very bad
for marketing as you can see), but the quality is inferior due to
horrible noise levels.

Regards
Guido

> BTW, this would compare to a 1 Megapixel true-color image and suggests
> that Panasonic uses 1 Meg CCD chips, same size as used by Sony in their
> actual consumer/prosumer 3ccd camcorder line. Sony do not use the
> pixel-shift hoax and output a true 1-Megapixel image (which is very bad
> for marketing as you can see), but the quality is inferior due to
> horrible noise levels.

BTW it would be better if Panasonic not used pixel shift and also output
a true 1-Mega image instead of the fake pixel-shifted 4-Mega, and less
noise than the Sony.
Such clean 1-Mega image could be better upscaled to 4-Meg if required by
appropriate algorithms in software.
But stupid megapixel marketing prevents more reasonable solutions...

Regards
Guido

"this old user" <> wrote in message
newsm%Ec.19921$...
>
> "Wayne J" <> wrote in message
> news:aDWEc.84527$. ..
> > I notice that Panasonic is coming out with a video camera, the PV-GS400,
> > that is capable of taking 4 megapixel stills. Normally the still
> capability
> > of video cameras is pretty poor due to the tiny ccd sizes, but the area
of
> > this sensor is pretty large.
>
> I always thought the still quality had nothing to do with the size of the
> sensor but instead the type pf sensor (vs. a digital still sensor) and the
> quality of the lens.
>
>

It has more to do with the size of the sensor than anything else, unless
maybe you're using really crappy 3rd party lenses.

Mark

"Wayne J" <> wrote in message
news:aDWEc.84527$. ..
> I notice that Panasonic is coming out with a video camera, the PV-GS400,
> that is capable of taking 4 megapixel stills. Normally the still
capability
> of video cameras is pretty poor due to the tiny ccd sizes, but the area of
> this sensor is pretty large. I think it must be close to a 5/8 ccd in
total
> area. Does anybody think that this camera has the potential to produce an
> image as good as a 4 megapixel digital camera with a similar sized ccd?
How
> many pixels would this sensor have? Is the image interpolated? What is
pixel
> shifting?

With pixel shifting, the three sensors are not precisely aligned. So you get
more spatial resolution, but you have to interpolate color information. This
works well, because of the physioligy of how the human eye works. Basically
they're copying how a CFA sensor works to increase resolution.

What would be really cool is if you could have a single sensor with three
sets of sensors (red/green/blue). But Foveon has been trying to do this for
years, and the results have not been great.