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Posted by Frank on 08/25/07 07:53
On Fri, 24 Aug 2007 13:28:00 -0400, in 'rec.video.production',
in article <JVC HD7 - full HD, really?>,
"Steve M" <nomail@for.me> wrote:
>OK, the JVC HD7 camcorder is advertised as producing "full HD" at 1920x1080.
The key word is "advertised", Steve. Because the GZ-HD7 is capable of
recording full 1920 by 1080 frames, it can safely be advertised as
"Full HD" without incurring the wrath of the FTC (Federal Trade
Commission).
In fact, I've seen different manufacturer's use the term differently,
in some cases meaning 1080 lines of video (as opposed to 720 lines of
video), and in other cases meaning square pixel 1920 by 1080 frames of
video (as opposed to non-square pixel 1440 by 1080 frames).
>How can this REALLY be the case when the resolution of the 3 CCDs is 1/4
>that? Steve Mullen lays it out at
>http://digitalcontentproducer.com/hdhdv/depth/hdv_02122007_mpeg2_cameras/
I first started to make note of the number of picture elements within
a given camcorder's imaging system back with the introduction of the
Sony HVR-Z1 series, which has only 960 pixels per scan line. Of
course, those are 1080i HDV camcorders which as per spec, record
anamorphically squeezed 1440 scan lines, so no claims were made at
that time about full anything. In fact, the term "Full HD" is a fairly
recent marketing invention and wasn't really found back in the early
days of HDV. JVC has used the term "ProHD" for some time now, however,
with reference to its GY-HD100, GY-HD110, GY-HD200, and GY-HD250
products.
As far as sensor pixel counts are concerned, the same thing is
happening with AVCHD camcorders.
Each of the three CCDs in the "professional" Panasonic AG-HSC1U
camcorder, for example, has just 520,000 effective pixels, which is
just slightly more than 25 percent of what's needed to form a 1920 by
1080 image. The AG-HSC1U records anamorphically squeezed 1440 by 1080
frames of video.
Meanwhile, Canon claims that the (single CMOS) sensor in its 40 GB
hard disk drive (HDD) model HG10 AVCHD camcorder has a 1920 by 1080
array. Additionally, Canon says that the HG10 records square-pixel
1920 by 1080 frames to its HDD.
And then there's the issue of sensor size. It seems that the average
person can't do simple arithmetic and doesn't realize that a
1/2.7-inch sensor is larger than a 1/3-inch sensor.
>Does anyone believe after reading this that the HD7 really produces "full
>HD"? I am skeptical. If I am wrong please let me know.
You're not wrong, just cautious, and a person who reads and
understands specs, something that I am convinced the average potential
purchaser of these sort of products rarely does. In fact, I seem to
recall reading a study a while back that suggested that less than five
percent of all buyers of technology products conduct research on the
Internet prior to completing their purchase. I was surprised at this,
having assumed that in this day and age, the number would be much
higher.
>Steve
--
Frank, Independent Consultant, New York, NY
[Please remove 'nojunkmail.' from address to reply via e-mail.]
Read Frank's thoughts on HDV at http://www.humanvalues.net/hdv/
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