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Posted by PTravel on 11/02/07 16:46
"Spex" <No.spam@ta.com> wrote in message
news:13imfvhg31fbe63@corp.supernews.com...
> There doesn't look much wrong with this screen grab. There is a
> considerable amount of sharpening that will catch the eye as the video
> moves. With so much native resolution there is little value keeping the
> sharpening that high.
Yep -- that's exactly what I'm seeing. I'm pleased with the resolution and
color fidelity of the image, but "shimmering" on movement is driving me
crazy.
>
> PTravel, why not post a RAW m2t clip to Rapidshare??? It won't cost you
> anything.
I'll try that this weekend.
>
> How hot are the whites in the image? Check their level.
I'll look this weekend.
>
>
> Smarty wrote:
>> 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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