After the EH55, no more IRE 7.5 DVD recorders were made by Panasonic.
Its not a design flaw.
Its compliance with an International standard that North America did not participate in.
Panasonic would have no reason to issue a "fix" because there was nothing to fix.
The problem is (two fold).
1) The Black level for IRE 7.5 is deliberately Stepped Up, above absolute Zero voltage to distinguish it from Sync level. In the early days on B&W television in the United States it was hard to figure out Black level from Sync level, so they manually separated them (in the United States.. and by association the North America "NTSC standard") so the electronics could be made simpler in early TV sets. As television became available around the world after WWII the circuits were more advanced so they did not need this separation.
2) It also "compressed" the available room for different black to white levels.. so North American "Setup" reduced the available luminosity levels.. think of it as a paler or less contrasty picture. And it remained that way until February 2009 when it was discontinued.
After the EH55 (and there were models of the EH55 that were International) all Panasonic DVD recorders assumed Black was IRE 0 (zero) and had the "full" range of luminosity.. so the picture was "richer" or more accurate.
Using an International EH58 or EH59 for example will assume the television signal, or signal from a VHS tape has Black at IRE 0, not 7.5, so the signal when played back will look "gray" because its calibrated so that "black" only appears on screen when the signal is at IRE 0.. because North American signals "never" produce or record Black as "zero" it always looks like the blackest black on screen in a program is always brighter than black.. and the whitest white at the top of the range is "squished" and blown out at the top.
Worse it gets complicated with actual DVD recordings to a DVD disc.
The DVD format assumes the North American "Setup" or IRE 7.5 base is "Removed" during recording, and turned back into an International Standard for DVD-video, which always starts at IRE 0. This removal process for a North American recorder works as designed. But an International recorder, does not attempt to "remove" this IRE 7.5 before recording it to disc. Not only is the signal starting out as a compressed "gray" but when played back on the same recorder into a North American TV.. it does not add back in the IRE 7.5 "setup" instead it plays it starting out at IRE 0.. so Black is rammed downwards, and the white level is pulled down.. but it was crushed during recording.. remember the "blown highlights?".. so it just looks all wrong.
There isn't a firmware fix, there isn't a hardware fix "exactly".
What has to be done is the North American IRE 7.5 setup level has to be removed, and then the signal "stretched" to fill the entire IRE range, and the upper White levels pulled down to make sure they aren't crushed against the ceiling. So its a two-part process.
A simple "Proc-amp" can do this.. but its a non-linear process.
1) Its has to be done in the analog domain, before the signal is submitted to the recorder
2) Its best done using a Waveform monitor to make adjustments on the Proc-amp, Brightness, and Contrast controls to "balance" the levels and avoid clipping at either end.. black levels and white levels.
People have tended to do this "subjectively" or "by their own personal tastes".. but its hard to reproduce that way.
Other people have acquired a few Proc-amps that have a built-in bar graph "Level" meter, that mostly alerts them when the blacks are too black, or whites are too white.. without requiring an actual Waveform monitor. Essentially they only light up on either end when broadcast standard levels are exceeded.. and in that way are rather like VU meters in audio production equipment.
Its been "hypothesized" that a simple AV to HDMI (box) and HDMI to AV (box) converter.. might.. strip out the IRE setup and "forget" to put it back in when converting back into AV.. but its never been pursued or proven to work. You would certainly incur some possible degradation in the conversion process.. and it wouldn't be as good as a Proc-amp.. but it should only cost about 40 usd.
Its also been "hypothesized" you could compensate by making a recording to DVD or exporting the raw MPEG2 from the recorder and putting it in a Non-Linear Editor program, like the Full SONY Vegas program which has "software Waveform and Vector" scopes.. and a software Proc-amp. But you would still incur losses from the initial conversion from analog to digital.. the levels would still be compressed, even fixing the IRE problem and stretching it back out.. you can't put back in actual video information that is no longer there.. its gone forever.. it just wouldn't look weird when played back anymore.. just look more "flattened" or "paler" than corresponding recordings from a Region 2 or any other International source with full IRE dynamic range.
This entire (issue) was addressed by Toshiba when they entered the North American market with their RD-XS series of recorders. The first generation, RD-X2, RD-XS32, RD-XS52, RD-KX50 (spain/costco) models all defaulted to IRE 0 and experienced this problem.
The next generation, RD-XS34, RD-XS54 received an additional menu option to "enhance" dynamic range, or turn it off.. which basically performed the compensation automatically.
Toshiba sold the same models with slightly different model numbers in Japan first, which is an IRE 0 country.. and had to refactor their equipment to work in the North American markets.. which included the United States and Canada.. so Canadian models of the EH55 also work the same way as the EH55 models made for the US market.. but the International EH55 model does not work the same way.. it defaults to IRE 0.
So its not so much a design flaw.. as a unique market "accommodation".. there will never be a "fix" for the International models.. because Panasonic never designed them to work in the North American market, they never sold those models in the North American market and have no plans to ever "fix" them.
Last edited by jwillis84; 01-25-2020 at 09:43 PM.