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DH30000 constrained image  

post #1 of 7
Thread Starter 
As I've posted a few times before, the DH30000 (Japanese version of the DH30000U) frequently slips into a degraded display mode. It seems likely that I am seeing the famous "constrained image" that is supposed to be built into all HDTV devices with wide bandwidth component outputs. With a little finagling it can be made to show the same HDTV tape constrained, or not constrained.

I know everyone's curious about what it looks like so I've done my best to photograph it for your viewing pleasure. They're pretty lousy photos. I still haven't figured out how to do this well.

I used a Olympus E10 digital SLR to snap a 2 inch wide portion of the image on a Sony 20" computer monitor. Source is a Leno show recorded and played back on the DH30000 and coupled to the monitor via a Keydigital transcoder. I used this display instead of my plasma to eliminate additional scaling.

So...here's constrained...

and not constrained...
post #2 of 7
Can DH30000 playback the recording made by Panasonic PVD1000 in HD? or in constrained image?

post #3 of 7
The shadow mask is the big contributor to picture degradation; also, there appears to be a moire interference effect between the shadow mask and your digital SLR. Try backing up a few inches. Also, if you have a front projection CRT display, you can take pictures without the moire effect altogether.
post #4 of 7
I've never been able to see any detail in Jay Lenos face at any resolution. Must be the heavy makeup.

post #5 of 7
Thread Starter 
Thanks, Dylan, I'll play around with the distance and see if I can come up with something with fewer artifacts.

What is most noticeable about the constrained image is the appearance of ringing or overshoot to the right of hard edges. It gives the image a confused appearance. Actually makes my eyes water! I was trying to capture that in the picture but it seems to be hard to capture the ringing.


It doesn't matter whether the recording is made on a DH30000 or a HD1000. It's entirely source dependent. KNBC Leno broadcasts are "neutral". If the DH30000 is in hidef mode the Leno tape plays hidef. If the DH30000 is in constrained mode Leno shows as constrained. Other source material will force the DH30000 into hidef mode, which is what I used to change the mode of the DH30000 for the photos. The recording capability of the DH30000 is not in question here. It always makes good hidef tapes. The only issue is it's ability to display those tapes in hidef in a reliable way.


Agreed. I should have used somebody else's face from that show.
post #6 of 7
I purchased DH30000 a few months ago. I've never
had "contrained image" problems with it. It played
all HD tapes recorded from networks and HBO/Show
just fine, its component output always shows HD-
quality picture. In fact, it has performed very
well that I plan to sell my HD1000 to buy another

Your DH30000 may have firmware bug since then has
been fixed.
post #7 of 7
Thread Starter 
Originally posted by spham17
Your DH30000 may have firmware bug since then has been fixed.
That's certainly a possibility. I have two machines that do it, one purchased in March, and second one in May.

There's always the chance that it will turn out to be a "good" firmware bug, allowing copy-once or copy-never material to be viewed unconstrained. Won't know till that stuff starts showing up. I have one copy protected BS tape that does display unconstrained, which is a good sign. :)
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