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Does Denon 2910 suffer from black crush?

1K views 12 replies 9 participants last post by  Joe Murphy Jr 
#1 ·
I'd appreciate hearing from anyone who has tried HDMI to DVI with the Denon 2910 (or a newer 3910 with the latest firmware) to see if black/white crush is present. I realize I could do DVI to DVI to avoid the potential problem, but it would be much easier to fish an HDMI cable through the ceiling to my HT1000, and I assume the next projector I purchase will be HDMI anyway. Thanks for the help! :)


Richard Fogg
 
#4 ·
NO


I'm running DVI and with the 2910 set to Black Expansion to EXPANDED and Picture Mode SETUP 0 IRE, and a 0 IRE output signal dials in almost perfectly with my factory settings for brightness.


If you find you have to push your monitor brightness controls well above standard, I suggest changing the Picture Mode SETUP to 7.5 IRE. If you still need brighter blacks, switch Black Expansion back to NORMAL. However, I might argue leaving Black Expansion set to EXPANDED, and raising your brightness controls, because EXPANDED provides a greater dynamic range of 0-256 grayscale.


I am interested to see if anyone has a negative opinion of using the 2910 Black Expansion option.


Bottom line, the 2910 offers a nice double layer of black level adjustment, and so far it meets my HT1000 needs very well.


The only think missing, would be a seperate White Expansion option, that would automatically remap/raise the upper IRE range over the DVI output. Then the use of RGB brightness/contrast adjustments on the HT1000 might not be necessary.
 
#6 ·
Thanks for the quick response(s) guys! That is what makes this forum such a great resource. Can you imagine going to the average Denon dealer and trying to get an answer to that question? Most of them would ask what black crush is and most of the rest wouldn't have had the opportunity to check out the player for that particular problem. Please, no flames here - I did say AVERAGE Denon dealer. I know there are some quality, knowledgeable dealers out there - but with the hundreds of DVD players, receivers, TVs, speakers etc. that most of these folks handle it is no wonder they can't be thoroughly up to speed on all of them. That's where good old AVS comes in.....


Richard Fogg
 
#8 ·
Quote:
Originally posted by Bob Pariseau
Bytehoven,

Have you checked to see whether the 2910 combination of 0 IRE and Black Expanded passes "Blacker than Black" data correctly?

--bob
I have a DVD-r test disc I made with IRE values from 0 IRE to 100 IRE, and the 2910 seems to be properly seperating 0 IRE and 7.5 IRE. So, I would say it is passing blacker than black, or blacker than 7.5 IRE.


I have not checked to see if the Black Expansion set to Normal mode crushes 0 & 7.5 IRE. I will check that out and report back. It may because, the normal mode maps 16-225 as the grayscale range. EXPANDED remaps it to 0-246 grayscale, and here I think they might have meant 0-256, which is the actual grayscale range.


I forget the real IRE value of the blacker than black pluge area that should be made to disappear. I am using 0 IRE, and that may be a little lower.


Maybe someone could comment on the actual value of the black pluge on mose test discs.


I should also note, I have a seperate high white test pattern on my DVD-r disc, with single steps from 90 to 100 IRE. The 2910 also outputs these perfectly. The 2910 Contrast setting in the Picture Mode menu, can be made to crush the whites as you boost the contrast, but leaving it set to 0 fine. I think I just started seeing the 99 & 100 IRE steps merge as I went from contrast setting 1 to 2.


I have an analog waveform that I could use to test the composite video signal, but no way to test the DVI output.


In this regard, I am looking forward to a Secrets review of the 2910, to see if it is indeed identical to the 3910 in it's video section.
 
#9 ·
Quote:
So, I would say it is passing blacker than black, or blacker than 7.5 IRE
I am cringing. Please stop.


BTB has nothing to do with "values encoded below 7.5 IRE."


You cannot encode a disc with absolute IRE values. BTB material refers to digital data below 16 (reference black). This data can be maintained in the video chain, or it can be clipped. And either of these can occur whether or not you are using a 0IRE output with analog outs, or a 7.5 setting with analog outs. Whether or not it clips depends on the specific source device's design.


It is undesireable to use the expanded mode if possible when using a digital output. This clips data below 16 (Blacker than black) and clips whites above 235. It also will invariably introduce contouring due to this expansion to PC-RGB levels.


You will have to explore what the player is doing when using a digital output and changing the IRE setup option, this hopefully would only affect the analog output, but it's possible that the player is adjusting the digital levels to achieve the proper IRE output instead of doing it only on the analog output.

Quote:
However, I might argue leaving Black Expansion set to EXPANDED, and raising your brightness controls, because EXPANDED provides a greater dynamic range of 0-256 grayscale.
As noted, expanding to PC-RGB is undesireable. It irretrevably destroys BTB and WTW data, and introduces contouring artifacts form this expansion. It does not necessarily lead to improved contrast ratios. Your blacks should be calibrated identically in either setting, however clipping peak whites will allow you the illusion of greater contrast. If you maintain Studio RGB, and thus maintain peak whites, then you have the subjective choice of whether or not to calibrate your display to maintain the peak whites, and how much, etc.
 
#10 ·
#11 ·
This just in ... on the BTB issue with the 2910, and if it clips the lower end of the black spectrum.


There are two general settings that affect the ouput of the black level.


Under the main SETUP menu, there is the HMDI/DVD Black Level. It has settings of NORMAL and ENHANCED. These settings effect the black level of the HMDI/DVI output and have no effect on the component or S-video outputs. Viewing the BTB signal of the THX video test pattern, the BTB portion of the signal passes with either setting. However, the ENHANCED setting brings the range of black level within the normal adjustment range of my HT1000. That way my brightness adjustmenst, are very close to factory.


The other black level setup is under the Picture Mode menu SET. The choices are 0 IRE and 7.5 IRE.


The 7.5 IRE passes the BTB signal from the THX video test pattern. The 0 IRE setting clips the the BTB signal, and no matter the brightness level of the HT1000, the THX shadow is no longer there.


I have now changed my 2910 setup to be ENHANCED and 7.5 IRE. I had to dial back my HT1000 brightness settings just a bit more properly adjust the BTB pluge, and it is now in line with the RP-91 in this regard.
 
#12 ·
Quote:
Originally posted by salrmrcrey
is everyone using dvi to hdmi instead of hdmi to hdmi on their sets ?

is there a difference as well?
I am getting the Denon2910 DVI hooked up to Samsung HLP6163 HDMI...will this work...is there a difference?


I have my Dish HD811 Sat receiver DVI to Sam HLP6163 DVI.
 
#13 ·
Bytehoven

That's incorrect. See page 29 of the DVD-2910 manual.


You have two RGB options to use with the DVI and HDMI outputs (HT1000 is a NEC HT1000 DLP projector and you're using the DVI input, correct?). There is a third option for HDMI, which is HDMI - YCbCr, but that's not available for a DVI input. You can select NORMAL, which is black at 16 and white at 235 and represents the digital video standard. Or you can select ENHANCED, which is black at 0 and white at 255 and represents the digital PC standard. In NORMAL mode, below black and above white are available parts of the signal. In ENHANCED mode, below black and above white are not available parts of the signal -- they're chopped off.


If your NEC doesn't look better when using the NORMAL mode (instead of the ENHANCED mode) of the DVD-2910, then it may expect digital PC levels (0 - 255) via DVI. And for anyone using the RP-91 in progressive mode, remember that it clips the blacks in that mode. Only in interlaced mode does it pass below black signals. Even then, there may be another problem with handling below black signals (see below).


On the analog input, your NEC probably clips any voltage below 0V. If black is set to 0IRE on the DVD player, below black information is clipped because it would be under 0V. If black is referenced at (pushed up to) 7.5IRE, below black is visible because the voltage from 0V (0IRE) to .053V (7.5IRE) is accepted by your NEC.
 
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