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Posted by Smarty on 11/02/07 14:43
For whatever it is worth, the frame grab looks to my (60+ year old) eyes as
being pretty typical of what I would expect for the HV20 with additional
JPEG processing applied. If I look at the very finest detail in the picture,
such things as the parking meter next to the car, small signage detail on
the lamp-post as well as the very tip of the lamppost, variegations in the
fencepost masonry, and other really small (just a few pixel wide / tall)
elements, my impression is that the capture has both preserved the edge
definition without fringing (unlike the cheaper Sonys which make artificial
edge sharpness by deliberate overshoot) and that there are no clear examples
of a defect. The areas you enlarged do look a lot different from the very
same areas which I enlarge using Photoshop, and thus your surrounding
magnified crops do look distorted but only when I look at your magnified
crops, and not when I look at the same high magnification of these areas
using the central 1440 by 1080 image. I am not sure what to make of all of
this.
None of these comments / observations apply, of course, to what you are
seeing on your TV set, or what the moving, dynamic video looks like versus
this single static frame. All I am saying is that the sensor and encoder
appear to be doing their job for this image without losing the fine detail,
and that the detail which is preserved does not (to my eyes) appear to have
distorted or exaggerated edges, color issues, or other evidence of a
defective sensor, encoder, or optics.
You alone can judge how faithfully this HV20 is capturing the true scene,
and in this regard, another still camera with high resolution might allow
you to make some further comparisons. I will often use my 8 MPixel Nikon to
take comparison shots for seeing where the video camera is weak. Obviously
the color gamut and resolution is worse in the video sample, but the
comparison to a reference can help discern the video shortfalls easier.
It will be interesting to see if any of my observations agree with anybody
else's. I am not an expert at all in these matters, and have cataracts to
further confuse the issue, so I am merely offering my 2 cents worth in a
sincere effort to be helpful.
I'm glad to keep working this to get more insight into what you are
encountering.
Smarty
<ptravel@travelersvideo.com> wrote in message
news:1193986489.385033.199060@q3g2000prf.googlegroups.com...
> On Nov 1, 7:51 pm, "Smarty" <nob...@nobody.com> wrote:
>> Paul,
>>
>> I have not seen the problem you describe, but it may be the fact that I
>> virtually never view the camera through its' HDMI port. I normally
>> capture
>> the Firewire data / .m2t, edit and author an HD DVD, and watch the
>> resulting
>> (non-transcoded) output. When I have made direct comparisons from tape
>> output from the camera's HDMI port versus playback of the HD DVD via
>> HDMI,
>> both had none of the "shimmer" you describe at the post on the DVI forum
>> you
>> linked to.
>>
>> I think the distinction you make regarding dramatic differences in HDMI
>> versus component is very telling, however. Both should contain high
>> frequency components up to about the same cut-off frequency / half-power
>> point. Each delivers essentially the same bandwidth and resolution. And
>> on
>> the 2 HDTV monitors I have here (both of which are 1080p) as well as the
>> computers / monitors I have for editing, the progressive display shows no
>> such effects. Perhaps the camera's 1080 interlaced signal is managed
>> differently on your monitor when seen through the HDMI port versus the
>> component input? I personally doubt the default setting of the camera's
>> sharpening would (if the camera is working properly) create this effect,
>> although reducing the high frequency energy with lower sharpening may
>> "solve" the problem at the expense of the camera's excellent resolution.
>> If
>> it were me, I would want to see another HDTV / monitor with HDMI to judge
>> how much of this, if any, is truly a camera issue. If it persisted in the
>> second monitor, I would get a replacement camera.
>>
>> The mpeg encoder is imperfect, and motion does stress the encoder so as
>> to
>> make fast pans take on a more under-sampled and degraded appearance, but
>> very very seldom have I seen any real macroblock effects or other
>> artifacting. My movies of Niagara Falls, with lots of vertical water
>> motion,
>> horizontal panning, and very agitated and tiny water details is about the
>> most stressing case I have tried, and even then the HV-20 was a vast
>> improvement over the older FX-1 as well as the recent Sony HC-3 my son
>> was
>> using.
>>
>> Although I am by no means an advocate of high priced cables, I might also
>> take a look at the HDMI cable being used between the HV-20 and the HDTV.
>> The
>> cables I use here are very inexpensive, work very well, and introduce no
>> particular problems, but it is remotely possible that high frequency
>> ringing
>> or other transient / overshoot problems could make the HDMI port look
>> bad.
>> This is a bit far fetched but worth a quick substitution if you have
>> another
>> HDMI cable to substitute.
>>
>> Please continue to update as I really would hope this problem is not a
>> deal-breaker.
>>
>> Smarty
>
> Smarty, thanks for the response. I've got a bunch of HDMI cables here
> but, as it happens, the one I was using is the best I have -- though
> money isn't necessarily a measure of quality, this one cost me $70.
> I'll try a couple of others this weekend.
>
> I took a look at a frame grab. To my eye, there are sharpening
> artifacts or, at least, some kind of high-frequency distortion. I
> posted it here:
>
> www.travelersvideo.com/hv20.jpg
>
> In the interest of bandwidth, I had to compress it rather heavily, but
> I think the artifacts show through. I REALLY want to like this
> camera, so I'm going to do some more extensive tests this weekend,
> including lowering sharpening and trying it in 24p mode (though my
> preference is to shoot 1080i/60).
>
>>
>> "PTravel" <ptra...@travelersvideo.com> wrote in message
>>
>> news:5oue5kFoaqqtU1@mid.individual.net...
>>
>>
>>
>> > "Smarty" <nob...@nobody.com> wrote in message
>> >news:J9aWi.29875$eD3.26430@trnddc03...
>>
>> >> Looks like nappy is beginning to get tempted...... I am anxious to see
>> >> how you and the other true professionals here find this camera, since
>> >> I
>> >> judge image quality and other related performance mostly as a
>> >> non-professional user.
>>
>> > As everyone here knows, I am far from a professional, either in skill,
>> > experience or knowledge. However, I've hit a significant problem with
>> > the
>> > HV20 that may result in my returning it.
>>
>> > Short version: there are significant motion artifacts in high-frequency
>> > detail, not unlike what you see with a Bayer-filtered single-CCD SD
>> > camcorder. The problem is dramatic on the camera's HDMI output, far
>> > less
>> > visible on component out. I'm still trying to figure out whether it's
>> > caused by over-sharpening in the camera, lousy HDMI circuitry, or
>> > something odd with my television.
>>
>> > I've discussed it at length here:
>>
>> >http://www.dvinfo.net/conf/showthread.php?p=768436
>>
>> > Since these videos are for my own personal use only, I may keep the
>> > camera
>> > as long as it looks good on the component output. However, I'm going
>> > to
>> > do so more tests this weekend. If the output continues to display
>> > these
>> > signficant high-frequency motion artifacts, I'm returning it and
>> > waiting
>> > until next year to buy either an AH1 or FX7.
>>
>> > I'm really disappointed -- I had high hopes for this machine.
>
>
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