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Posted by Spex on 06/27/07 16:44
Ty Ford wrote:
> On Wed, 27 Jun 2007 03:59:42 -0400, Mark & Mary Ann Weiss wrote
> (in article <ONogi.4210$M92.1067@fe02.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
>> grass, and the HDV CODEC can't handle all that high frequency detail without
>> generating spurious color information that shows up temporaly as a
>> shimmering effect.
>> I suspect that the color palette of HDV is less than 24 bit, because at
>> times, the picture shows striated bands of color, like a GIF image when too
>> many diverse colors are present. Ironically, the noisy imagers in this
>> camera should 'dither' the image and eliminate the banding, but it does not.
>>
>>
>
> 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.
The Sony HDV codec in the V1 is an embarrassment and is well known in
the broadcast world. Quite what Sony thought they were doing with the
progressive scan recording is beyond me.
I bought a HVR-V1e here in the UK and was astonished when the 25p was
played back. The image looked like it had been treated with a photoshop
filter. After a battle with Sony to take my complaint seriously the
admitted there had been a manufacturing fault and the camera was
returned for a upgrade of the firmware. The camera came back and there
were still horrendous problems with macroblocking in dark areas and in
areas of similar colour. Every edge was over sharpened and had an
obvious halo. Again these faults were reported to Sony and their
response was to say turn down the sharpening. But unfortunately I had
already tried that but before the over sharpening artefacts were removed
the imaged looked like it had been Gaussian blurred.
Sony gave up trying to fix the problems and offered a full refund as
they admitted the 25Pscan mode may not meet the users expectations. In
50i there were no such problems.
The US model also suffers progressive scan image problems although the
over-sharpening artefacts are much reduced from the V1E model. Just
compare a locked off 60i image to either 24P or 30p and make sure you
look at the dark areas of the image and areas of similar colour will be
lacking detail and macroblocked compared with 60i. You will also see
much more mosquito noise round contrasty fine detail in progressive mode
compared to interlace.
Some time later I purchased the Canon XH-A1 and I am delighted with the
way its encoder handles motion in both 25F and 50i. Resolution tests
might put the V1e 50 lines more res vertically but as soon as the image
moves the Canon image hold up to some very close scrutiny where the Sony
fails immediately.
The HVR-V1 has received glowing reviews but this is a reflection of the
competence of the person reviewing the camera rather than the camera
itself. There seems to be a cadre of pseudo intellectuals making
pronouncements about a subject they demonstrably know very little about.
I know people who have been banned from web fora for voicing those
opinions.
Avoid the HVR-V1 unless you are only interested in interlaced recording.
To now hear that the V1 has crappy audio does not surprise me. I didn't
get that far as the image it captured was a joke.
S
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