D-Ext definitive answer?

gumbyandpals · Posted: 10 Dec 2014, 15:17

Has it ever been established with certainty what the D-Ext function on LD players does? The player manuals with it describe it as a dynamic range extender, but it's not clear if it's adaptive or not, or really what it does to the signal.

disclord once wrote this:

disclord wrote:

its just a luminance dynamic range expander that makes the image have more pop, but isn't for switching between 0 and 7.5 IRE setups or discs. It's not for accuracy because it's adaptive and floats the black level depending on picture content, which no switch for setup level would do and it would change the chroma levels too, which D-EXT doesn't do. (D-EXT stands for Dynamic range Extender)

I wish he had posted the source for that information. Anyone have any info?

Guest · Posted: 11 Dec 2014, 09:36

I always heard the opposite, that the D-EXT only should be used for Japanese pressings (different IRE than US pressings).

But on my tweaked HLD-X9 it is always on because it gives me a better image quality, no matter what pressing.

//Birdie

rein-o · Posted: 11 Dec 2014, 15:07

I though I remembered reading from disclord??? or someone else that its for your TV and Discs almost like birdie is saying.
so if you setup your TV for Japanese LDs which are set darker, you would keep the D-ext on??? and then when you play a US disc you turn it off???
or something like that.

but I thought it was on this forum, the info on what it does, just can't remember where now.

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substance · Posted: 11 Dec 2014, 16:49

More important question is weather it would clip blacker than blacks. I read multiple times that it does. If this is the case, one should steer clear

gumbyandpals · Posted: 11 Dec 2014, 17:47

Proper NTSC (North American) video shouldn't have any real information below black (7.5 IRE) right? My best guess is that it eliminates the 7.5 IRE pedestal, shifting black down to 0 IRE thus "expanding" the range. If your set is calibrated for 7.5 IRE this would result in "clipping" if you didn't adjust your brightness setting.

I don't know if laserdisc players do any setting of the black level in their processing. If they do, then North American players would display Japanese discs incorrectly and the D-Ext could fix that. If they don't set black level then the D-Ext would probably clip blacks on Japanese discs and bring North American discs' black level to 0 IRE requiring you to adjust your TV for 0 IRE.

I could also be wrong about the whole black level shifting thing, which is why I brought this topic up. Someone who knows about NTSC video needs to monitor the signal on a scope to see what's going on. I tried a while back but I didn't really know what I was looking for.

sonicboom · Posted: 24 Sep 2019, 17:00

I was curious about D-Ext for some reason. The manual for the CLD-R7G has some info on what it does but it is in Japanese.

http://manuals.lddb.com/LD_Players/Pioneer/CLD/CLD-R7G/Pioneer-CLD-R7G-JP.pdf

Using Google to translate the document I came up with this:

Quote:

Pg. 4
D-EXT
Increased stability of horizontal and vertical synchronization against disturbance noise. Set normal black a little brighter than true black Say up. However, in terms of image quality, the video signal Will reduce the dynamic range and degrade the signal-to-noise ratio. The In particular, it interferes with the gradation of dark areas, and black sinks to true black. Instead, the entire screen becomes white. Currently, most laser discs on the market in Japan With setup, without setup, focus on the screen. Limited to a few discs. D-EXT circuit eliminates setup and turns black into black Of Y signal (S terminal) and composite signal (pin jack) It is provided for each. If the disc is not set up, perform “blackout” This behavior must be turned off.

Note: When D-EXT is turned on for composite output, the color signal is expanded along with the luminance signal. If the color becomes dark when viewed on a monitor without AGC, etc. There is a case. Only the luminance signal is expanded at the S terminal output. There is no such thing. When D-EXT is turned on,Depending on the situation, the screen may flicker during the still image. Not.

Pg. 19
Press the D-EXT button.
Please note Depending on the software and the TV to be combined, It may be difficult to see. In that case, turn off D-EXT please.

Each time you press the button, the display changes as follows.
D-EXT off: Normal image quality (indicator off)
D-EXT ON: A clear screen with black black(Indicator lights up) D-EXT

D-EXT can also be turned on / off using the remote control.

I can't think of a reason to ever use it and so my curiosity is satiated.

ldfan · Posted: 28 Sep 2019, 09:37

This is what disclord wrote about D-Ext (first post).....

https://forum.lddb.com/viewtopic.php?p=55137#p55137

benmbe · Posted: 28 Sep 2019, 09:43

I have the HLD X9 and when I use the D-EXT on any Laserdisc US or Japanese the black bars are darker and I prefer this it's good

Just my pennies worth Guys

Kind Regards to all

:wave:

D-Ext definitive answer?

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