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Posted by Smarty on 07/10/07 18:07
Mark,
HDV's 25 MBit/sec MPEG-2 is substantially better than the rate used for
delivering virtually all HD content to the home, and is ***NOT*** the
culprit. Overloaded codecs, flash A to D converters which take too long to
settle, and DSP algorithms which don't have enough processor bandwidth are
among the cost-saving measures used in some camcorders which create the
erroneous observation that the HDV format somehow is at fault.
Blind, deaf, and bribed people being paid to overlook artifacts, as you
state, is really an even more unfair indictment.
The reality of the matter is that HDV video with 25 MB/sec video need not
show any visible artifacts ***IF** the real-time encoder has enough
horsepower. I will fully admit that many HDV camcorders, perhaps most of
them, are marginal in this regard, and can indeed be stressed to show this
flaw in some circumstances.
I can also list countless examples of practical limitations which exist to
driving a Ferrari, serving a $10,000 bottle of champagne, or owning a $7200
Rolex. My point is that we as engineers are *****always***** trading
performance and cost, and that HDV was, is, and will continue to be a format
designed and engineered very deliberately for low cost consumer and
"prosumer" markets.
It should not take a brilliant insight to realize that Sony and others make
very deliberate market segmentation decisions when choosing whether to make
a $2000 consumer HDV camcorder work as well or as poorly as it does.
I think it is comical therefore to waste a lot of your breath on how poor
HDV is, and especially to falsely conflate and confuse specific camera
defects with the HDV format in general.
Smarty
"Mark & Mary Ann Weiss" <mweissX294@earthlink.net> wrote in message
news:EvHki.41015$Zr1.35345@fe08.news.easynews.com...
>> > I've started a small site with example footage and stills taken from an
> HDV
>> > camera, the Sony HVR-V1U. Aside from it's terrible audio, the camera
>> > produces decent images in sunlit environments, but there are a number
>> > of
>> > artifacts which are changing in a distracting temporal manner, as the
> camera
>> > pans across scenes.
>> >
>> > I put some examples up here:
>> >
>> > http://www.basspig.com/hvrv1u_HDV_artifacts.htm
>> >
>> > HDV is really severely compressed and breaks down badly with imager
> noise,
>> > so in low light situations, the CODEC is overstressed and picture
> quality
>> > nosedives. This is also true with busy images, like a pan across a
> grassy
>> > field (the grass shimmers because the imager resolves individual blades
> of
>>>>>>> >
>>
>> Where were you last year when rabid HDV supporters were beating their
> chests
>> and wailing about how wonderful the picture was?
>>
>> I was just out with a crew with 4 Sony HDV cameras shooting a documentary
> at
>> a sporting event. I asked them about panned moves and compression
> artifacts.
>> I took their "no problem" answer at face value.
>>
>> As with audio, apparently, some people are pickier than others.
>
> Apparently, some people, including Grammy award-winning skydivers, seem to
> suffer from selective blindness to certain glaring artifacts.
> The thing about HDV is that it depends what the camera is pointed at and
> how
> it is moving, panning or zooming in a shot. I have some footage I shot in
> Manhattan on a sunny day that looks pretty darned good. Then I have some
> footage I shot on a grassy playing field that looks like garbage. Then
> there's the in-between shots that neither look all good or all bad, but
> have
> one or more "minor" visual artifacts that *I* notice, but others seem to
> deny the existence of.
> In this industry, the so-called "pros" --the guys with the Emmys, Grammys
> and other accolades are the ones people believe, but I am finding out
> little
> by little that these people are either blind, deaf, or paid to ignore
> these
> artifacts by the big camera companies, like Sony.
>
> Mark Weiss, P.E.
> http://www.basspig.com/hvrv1u_HDV_artifacts.htm
>
>
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