New Foveon sensor for digital camcorders

Jorge Prediguez wrote:

Foveon is working on a new sensor for video cameras. This will
guarantee the best video quality ever. Sigma will be releasing the
first video camera with this record breaking technology.

Crawl back to R.P.D. where you belong, you pathetic attention whore.
It's bad enough when Brette blathers about his D60; your
obsessive/compulsive Foveon spew is even further off topic and is most
unwelcome. This is a FILM oriented group, and I doubt anyone here wants
to read about Sigma videocameras or the sensors within.

-Greg

PTRAVEL wrote:

Actually, it wouldn't -- it's primary advantage would be size and weight.
3-chip video cameras offer exceptional color reproduction because dichroic
prisms split the light into primary colors, each of which is directed to a
monochrome sensor. The result is high color accuracy without interpolation
or approximation, as well as excellent low-light performance, as there is no
light loss involved, except that small amount attributable to the prism.

As a side question: if full colour information in each pixel is not so
important (as has been repeated again and again here), why do higher end
camcorders use three CCDs and a prism to achieve it ?
--

Alfred Molon
------------------------------
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In article ,
Alfred Molon wrote:
PTRAVEL wrote:
Actually, it wouldn't -- it's primary advantage would be size and weight.
3-chip video cameras offer exceptional color reproduction because dichroic
prisms split the light into primary colors, each of which is directed to a
monochrome sensor. The result is high color accuracy without interpolation
or approximation, as well as excellent low-light performance, as there is no
light loss involved, except that small amount attributable to the prism.

As a side question: if full colour information in each pixel is not so
important (as has been repeated again and again here), why do higher end
camcorders use three CCDs and a prism to achieve it ?

It is all about trade-offs. If you can get full color information without
any loss in resolution, with same sensitivity and signal to noise ratio,
and in a convenient package, it is a better deal than a sensor that provides
a lower color resolution.

For video cameras, the resolution is more or less fixed, and compared to
the overall size of a (professional) video camera, using three sensors
is no big deal. I don't know about sensitivity issues. With analog video
cameras, you don't really want to do any complicated bayer pattern
image reconstruction. Maybe bayer pattern sensors make sense for HDTV
video cameras.

For photo cameras, bayer pattern sensors provide (at the moment) the best
trade-off in most cases.



--
The Electronic Monk was a labor-saving device, like a dishwasher or a video
recorder. [...] Video recorders watched tedious television for you, thus saving
you the bother of looking at it yourself; Electronic Monks believed things for
you, [...] -- Douglas Adams in Dirk Gently's Holistic Detective Agency

"Alfred Molon" wrote in message
...
SNIP
As a side question: if full colour information in each pixel is not so
important (as has been repeated again and again here), why do higher end
camcorders use three CCDs and a prism to achieve it ?

It has been explained several times as well ;-)

Camcorders are limited in the number of pixels they can output, given the
bandwidth limits of the various video signals. The only improvement
possible, and given the limited image size not prohibitively expensive and
heavy, is color resolution (however little benefit it brings).

There are practical limits to increases in zoom range or low light
capability, so if one seeks to differentiate the product offering from
cheaper models in the line-up, slightly more accurate color quantization is
basically all that's left to do.

Digital still cameras are not bound as strictly to maximum image size in
pixels, so one can make a trade-off between fewer pixels with higher color
accuracy than the human eye can see in normal output, or adding more
sensors/pixels that increase luminance resolution AND improves color
accuracy, at the expense of higher storage size, lower capture frequency and
higher cost. Increasing the number of sensors is the avenue chosen by most,
also because the Bayer CFA sensor fabrication process is very mature and
relatively low cost due to high yield.

Bart

"PTRAVEL" wrote in message ...

A Foven-based camcorder might be an improvement, possibly even a dramatic
improvement, over single-CCD camcorders, assuming the sensor was of
sufficient size. No Foveon-based camcorder will produce results equivalent
to a good 3-CCD prosumer unit, e.g. VX2000, GL2 or XL1, absent significant
improvements in the underlying technology.

The new Foveon P&S due out soon is rumored to have better video
quality than any consumer video device, and rivlas 3 chip pro designs.
Not a bad deal for a $300 pocket P&S. It is also rumor to be able to
capture full size 4.5MP still shots while it is shooting video.

On Tue, 29 Jun 2004 15:55:23 -0700, "PTRAVEL"
wrote:

Actually, it wouldn't -- it's primary advantage would be size and weight.
3-chip video cameras offer exceptional color reproduction because dichroic
prisms split the light into primary colors, each of which is directed to a
monochrome sensor.

So, you are saying that companies like Panavision, Arri, Kinetta and
Thomson are wrong using a one-chip for their high-end e-Cine camera's?
Interesting

cheers

-martin-

--
"Light travels faster than sound. That is why some people appear bright
until you hear them speak."

"Georgette Preddy" wrote in message
om...
"PTRAVEL" wrote in message
...

A Foven-based camcorder might be an improvement, possibly even a
dramatic
improvement, over single-CCD camcorders, assuming the sensor was of
sufficient size. No Foveon-based camcorder will produce results
equivalent
to a good 3-CCD prosumer unit, e.g. VX2000, GL2 or XL1, absent
significant
improvements in the underlying technology.

The new Foveon P&S due out soon is rumored to have better video
quality than any consumer video device, and rivlas 3 chip pro designs.
Not a bad deal for a $300 pocket P&S. It is also rumor to be able to
capture full size 4.5MP still shots while it is shooting video.

Rumoured by you.

"Georgette Preddy" wrote in message
om...
SNIP
The new Foveon P&S due out soon is rumored to have better video
quality than any consumer video device, and rivlas 3 chip pro designs.
Not a bad deal for a $300 pocket P&S. It is also rumor to be able to
capture full size 4.5MP still shots while it is shooting video.

You are wrong, again, as usual.

It is a Polaroid P&S, and captures 1440 x 1080 pixels (1.56 MP):
http://www.dpreview.com/news/0406/04062102foveonf19.asp
This will, in addition to still images, produce video clip capture at VGA
(!) resolution.

Bart

Alfred Molon wrote:

As a side question: if full colour information in each pixel is not so
important (as has been repeated again and again here), why do higher end
camcorders use three CCDs and a prism to achieve it ?

Perhaps because requirements for video are somewhat different than for
stills.

For example, my TV displays at 35dpi. That's utterly unacceptable for
a print but seems to work fine on the telly. In fact I've looked at big
expensive TVs in shops that are probably less than 20dpi and it's
surprising how close a viewing distance you can use before the lack of
resolution becomes intrusive. I can't explain why this should be, but
it suggests that something different is going on with motion pictures
than static ones, and assumptions about quality requirements made for
one should not be carried over to the other.

Alternatively it may just be a marketing phenomenon. Note that most
video delivery systems (including analog PAL,NTSC, digital MPEG-1,2)
have reduced chroma resolution.

- Len

"Alfred Molon" wrote in message
...
PTRAVEL wrote:

Actually, it wouldn't -- it's primary advantage would be size and weight.
3-chip video cameras offer exceptional color reproduction because
dichroic
prisms split the light into primary colors, each of which is directed to
a
monochrome sensor. The result is high color accuracy without
interpolation
or approximation, as well as excellent low-light performance, as there is
no
light loss involved, except that small amount attributable to the prism.

As a side question: if full colour information in each pixel is not so
important (as has been repeated again and again here), why do higher end
camcorders use three CCDs and a prism to achieve it ?

"Full color information" is a meaningless phrase. All camcorder sensors
provide full color information. What varies is how they do it.

I've described, in this thread, why a Foveon chip-equipped camcorder will
not produce as good an image as a 3-ccd camcorder.


--

Alfred Molon
------------------------------
http://groups.yahoo.com/group/Olympus_405080/
Olympus 5050 resource - http://www.molon.de/5050.html
Olympus 5060 resource - http://www.molon.de/5060.html
Olympus 8080 resource - http://www.molon.de/8080.html