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Old July 5th, 2006, 09:56 PM   #1
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DV.com's Texas shootout questions?

Just curious why there has been such little discussion on the shootout in regards to the HD100. The six frame "freeze" issue! Why hasn't this been refuted? I have never heard of it befor, yet the DV report now leaves it as gospel fact. Whats up? Also the low scores for motion compression. I'm shocked that a 6GOP structure would be so outperformed by a 15GOP system. I am a long time HD10 user and have never encountered these issues, so I figured the HD100 would only be a step up in perfection. Did they have a gimped cam? Why isn't the JVC community disclaiming these points? Maybe after fighting off SS for so long everyone is tired of defending technical problems.
So bottom line. Good review or bad?
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Old July 5th, 2006, 10:27 PM   #2
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There was a dvinfo.net thread going on the subject. I asked that they put up their m2t files for us all to take a look at. I'm hoping the thread comes back to the surface with the m2t's that show the issues.
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Old July 6th, 2006, 12:26 AM   #3
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We'll host a few choice .m2t files from our media server, but the bulk of the video will eventually be made available in the form of a DVD set from Mike Curtis of HD For Indies. This will probably happen around the time that the participants get back together for a screening party in either Austin, Houston or Dallas in the very near future.

However, I can't help but feel bothered by the confrontational posturing of the terms "refute, gospel, defend and disclaim." There's nothing that needs to be refuted or disclaimed, nor does this community need to band together for any purpose other than the one it's already engaged in, which is discussing the camera's technical operation and its creative applications.

What our shootout proved was something I had suspected all along, which is that there is no clear "winner camera" or "loser camera" in this price range. Each one has its own particular strengths and weaknesses, and anyone who fixates on some negative aspect of what they read has sadly missed the bigger picture of the overall test results.

We did not have a gimped cam. We had two perfectly functioning HD100's. The correct assesment of this situation is that this particular HD100 community is too busy happily shooting and creating with their cameras to bother caring very much about it. And that's a good way to be. Forget about numbers and ratings and results and try to focus instead on getting the most out of what you've got. It's much more productive to share, create and explore. That's what this community is for... so please take the battles elsewhere. Thanks in advance,
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Old July 6th, 2006, 12:56 AM   #4
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Shootout critique...

One thing I noticed that was weak in the shootout was the comparison of the two JVC lenses, the standard and wide. They casually brushed off the resolution results with a somewhat flippant comment like maybe the resolution chart was askew... or whatever. Also what about resolution at less than ideal apertures? Edge to edge and corner to corner?

In an earlier test report, as I recall by the same team, the wide lens brought the cameras resolution up -- as I recall they said the picture looked more like the Varicam's, which is of course is a step down in CCD resolution, but the intent was a positive comment.

But resolution issues aside, the real problem was the seeming lack of attention to some crucial elements of real world lens performance. Two in which the lenses seem to me to exhibit large differences are:

1) The amount of barrelling at the short end of the lens. The wide lens has much less per my own informal comparisons, even at it's much shorter focal lengths. This really matters in certain compositions where you have vertical or horizontal elements such as buildings in a skyline, etc., even corners in a room. And of course with the 16:9 frame the horizontal lines are affected in an even more obvious way. There is some visible in horizontal elements in the optional lens at full wide, but not too bad

2) Breathing (the image zooming in or out when changing only focus). The stock lens breathes too much to allow a rack focus that isn't also a zoom shot. The wide lens breathes almost imperceptibly.

This post is intended only as a constructive comment to round out the test results. I tremendously respect the testers and know that they didn't ignore these lens issues from lack of knowledge, but probably just from lack of time.

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Old July 6th, 2006, 01:03 AM   #5
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It's funny but the think that struck me about it was how much better the JVC's stills looked as compared to the hvx. In my book that was a pretty resounding endorsement. And let me tell you, some of the fanboys weren't too thrilled about it.
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Old July 6th, 2006, 01:16 AM   #6
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Quote:
Originally Posted by Tip McPartland
One thing I noticed that was weak in the shootout was the comparison of the two JVC lenses, the standard and wide. They casually brushed off the resolution results with a somewhat flippant comment like maybe the resolution chart was askew... or whatever.
I agree! I'm hoping for an in depth comparison of the different lenses. It should really be a separate review for the simple reason that the optional lenses are so phenomally expensive. $13,000? You can buy a lot beer with that much dosh.
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Old July 6th, 2006, 01:54 AM   #7
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and YOUR point is?

Good point Chris!

The correct assesment of this situation is that this particular HD100 community is too busy happily shooting and creating with their cameras to bother caring very much about it. And that's a good way to be. Forget about numbers and ratings and results and try to focus instead on getting the most out of what you've got. It's much more productive to share, create and explore.
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Old July 6th, 2006, 04:38 AM   #8
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Quote:
Originally Posted by Chris Hurd
However, I can't help but feel bothered by the confrontational posturing of the terms "refute, gospel, defend and disclaim." There's nothing that needs to be refuted or disclaimed, nor does this community need to band together for any purpose other than the one it's already engaged in, which is discussing the camera's technical operation and its creative applications.
Don't feel bothered. These are straight-up questions. The fact that no one has refuted the points or have even brought up the points I made, speaks volumes. A six frame freeze is nothing trivial. In fact in my book it is down right broken. And I am shocked it is so. The fact it hasn't been thouroughly discussed here already, is unbelievable.

"The correct assesment of this situation is that this particular HD100 community is too busy happily shooting and creating with their cameras to bother caring very much about it."

A smart lot your making them out to be. No one ever noticed it befor, ever? And if they did, they don't care? I just find this hard to imagine.

You stated that they used two perfectly functioning cams. Neither experienced and dreaded "split-screen effect" as reported in the article. Is it possible that two cams that exibit "slit-screen" may not show the "six-frame freeze" and vice versa? Or is this determined to be a fixed fault of the 6GOP compression with no fix possible? Could this not be another example of a miscalibration? The cams have had various technical issues since release. What makes anyone so sure this isn't another one?
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Old July 6th, 2006, 05:37 AM   #9
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Quote:
Originally Posted by Ken Hodson
The six frame "freeze" issue! Why hasn't this been refuted? I have never heard of it befor, yet the DV report now leaves it as gospel fact.
Actually Adam Wilt mentioned this same issue when he reviewed the HD-100 for DV Magazine; you can probably find it in the archives on their site.
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Old July 6th, 2006, 05:43 AM   #10
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Re: "freeze" thing, I personally have never observed it and am unable to duplicate it. Seems it's pretty subtle, if it exists at all. According to JVC guys I speak with, this was the first time for them to hear of it. Until they duplicate it, it seems there's not much to say either way.
As for the article's conclusions regarding compression, the images didn't seem to match the written descriptions. The HD100's stills looked absolutely perfect to me. The other cameras' stills seemed to have gross compression errors, so it was hard to understand the article's written conclusions. I figured there might have been something wrong with how I was viewing them or maybe there was a mistake in the article? What did everyone else see?
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Old July 6th, 2006, 05:57 AM   #11
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Quote:
Originally Posted by Tip McPartland
I tremendously respect the testers and know that they didn't ignore these lens issues from lack of knowledge, but probably just from lack of time.
That is a very correct assessment, Tip. We were very much pushed for time to get everything accomplished that we wanted to.

That means we didn't have time to do in depth analysis of each lens. As was mentioned, this is probably a separate review in itself. To me that means taking a single camera and throwing every available lens on it and seeing what happens to the image.

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Old July 6th, 2006, 11:49 AM   #12
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Quote:
Originally Posted by Bob Diesso
The HD100's stills looked absolutely perfect to me. The other cameras' stills seemed to have gross compression errors, so it was hard to understand the article's written conclusions. I figured there might have been something wrong with how I was viewing them or maybe there was a mistake in the article? What did everyone else see?

I saw the same exact thing.

And every single time I look real close at HD100 footage on my dell lcd I'm surprised at how clean the picture is. We did some fast action (soccer) shooting a few weeks ago. Pausing the playback in between REALLY FAST pans holds up completely! I've never seen any kind of "bad compression" coming out of my HD100, though I have seen it from a 15gop HDV camera. (lets leave it at that heh)

Ken can you describe the "6-GOP freeze?" This is the first I'm hearing of that phenomenon.
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Old July 6th, 2006, 02:20 PM   #13
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Lag...

My old JVC KY-D29/BR-D40 D-9 camera would show picture lag if the DNR was turned on. It was a strange effect, like part of the picture would stay the same a few frames in zooms and pans, then catch back up. It was like the picture was "swimming."

This DNR was "3-D" which meant that it was identifying certain differences in the frames as noise, and using the pixels that it "decided" were not noise from one frame or the other, that is using pixels from frame #1 to replace "noise" in frame #2 or vice versa. It seemed that the DSP wasn't quite strong enough to do this in real time like it was supposed to do as I had the camera set up, and I always used the color matrix. The camera's manual in fact claimed that it could do DNR with "no picture lag." Yeah, maybe if the color matrix or other processes were turned off.

I think picture lag can happen to a camera when the DSP is asked to do more than it can do, so the question would be, "What DSP challenging functions were active during the times when this effect was evident in the Texas test?"

Was the DNR on? Were a LOT of other processes such as color matrix calculations taking place? How many pixels did the pixel masking routine have to recalculate? How calculation intensive are the sharpening functions and were they on? And so on.

At what point in the accumulation of the dozens of processes the camera can do simultaneously is the DSP challenged beyond it's ability to calculate the entire resultant picture in real time? If this only happens when an unlikely "perfect storm" of numerous DSP processes are active, and only then when generating very complex images, then it may not be much of a problem.

This is likely the case and would explain why none of the many video savvy HD100 owners here have not seen it over months of real world usage.

Tip
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Old July 6th, 2006, 02:59 PM   #14
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Hey maybe this 6 frame freeze is fixed in the hd110! Cool

I have actually noticed this with my new hd100 units, it is rare but there have been instances where the picture seemed laggy. I thought it had something to do with the tape but after some tests I realized it was something else.
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Old July 6th, 2006, 03:48 PM   #15
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Quote:
Originally Posted by Ken Hodson
These are straight-up questions. The fact that no one has refuted the points or have even brought up the points I made, speaks volumes. A six frame freeze is nothing trivial. In fact in my book it is down right broken. And I am shocked it is so. The fact it hasn't been thouroughly discussed here already, is unbelievable.

"The correct assesment of this situation is that this particular HD100 community is too busy happily shooting and creating with their cameras to bother caring very much about it."

A smart lot your making them out to be. No one ever noticed it befor, ever? And if they did, they don't care? I just find this hard to imagine.
I am one of those people too busy having fun and being paid to shoot films instead of obsessing over something I have never witnessed with my own eyes.
It seems no one else around here has ever seen it either, so what is the point in refuting it?
It isn't that we don't care, but as a community of HD100 USERS it isn't our job to "defend" the camera and claim the "6 frame freeze" doesn't exist if we haven't viewed the offending m2t for ourselves.
Maybe it does exist and Adam's assessment is correct, maybe there was a glitch in the hard drive recording methods, maybe it is a playback issue, maybe it was a tape dropout, maybe it is an isolated incident. Who knows? What is the point in having this discussion now if when the camera has been on the market for a full 12 months and this is the first time we've ever heard of this "phenomenon?"
I've shot some very fast moving action material, watched it frame by frame, on LCD monitors and on the big screen and nothing abnormal has ever jumped out at me.
I'll wait to view the results for myself before I will comment further.


Quote:
Originally Posted by Tip McPartland
e real problem was the seeming lack of attention to some crucial elements of real world lens performance.
Yes the Th13x3.5 lens is much sharper than the stock 16x5.5, especially edge to edge. It hardly breathes and doesn't seem to vignette at longer focal lengths. The CA is lessened considerably but still exists. I posted TIFF frame grabs from both lenses a few months ago that clearly demonstrate the differences. I also posted a real-world "rack focus" breathing comparison. I'll try to track them down.
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