Originally Posted by *UFO*
If you are referring to using that specific image for testing black crush, the image itself is crushing blacks.
i only grabbed that image from a website which i was reading at the time, and dont know its creator or exact purpose (and i presume it has the same application as the lagom.nl test image). to be safe, so we are talking about a known variable, lets use this similar image from the dutch video calibration website
note: anybody using the image, for accuracy it is usually safer to download and save the image to your pc, and then view it in an image viewer (instead of viewing it directly from the web-browser)
Originally Posted by *UFO*
On all my properly calibrated displays, including a laptop, half the squares are completely missing. That image is designed to not show squares on displays set to limited. That is what you want to see.
i am suspecting i dont understand what you said correctly, because...
when i complete my software calibration process for a display, and have set correctly my black levels with the "pluge w/greyscale" image from DVE (for ex using s brightness level of 51 on the tv), then the outer most of the 3 vertical grey/black bars in that DVE pluge test image just
blends into the black background. and if at that setting i then go to view the "black level"blocks test image from the dutch website on the same display (from the link i just posted above), i can still see most of the black boxes in their descending order of bright/dark, except for maybe the last 1 or 2 darkest boxes in the top most row (with. my brightness level on the sony tv set to +/- 51)
imho, if we cant see the top 2 black rows on our display after we have set our brightness/contrast/gamma levels, then there is some serious clipping of black levels going on (am happy to be proven wrong if some avscience experten can explain to me why). i just use that "black blocks" test image from the dutch website as a final check to see if i am in the right ballpark after doing a software calibration on tv/pc-monitor with DVE (i have no hardware calibration device), but afaik most
of them should be visible.
in fact i can replicate your experience of "top 2 rows becoming invisible" if i incorrectly set my AMD video card CCC output to full 0 - 255 (this problem occurs with the tv set to full or limited for its HDMI input). With that same (incorrect) setting on the pc grafix card driver video output, , the darkest vertical bar of the DVE pluge test pattern then stays completely invisible even if i set my brightness level on the tv to 100 (confirming to me i would have made an error in my settings). if on the other hand i set my AMD CCC to limited (16-235) and the sony tv to Full (or limited) on HDMI input, i dont have that black level clipping (maybe i am not using the right term there ?) and my vertical black/grey bars on the DVE pluge test image is then correctly visible and can be set correctly with my tv brightness level.
For me the experience is
amd ccc on full 0-255, and sony hdmi input on full = severe black clipping on DVE test pattern
amd ccc on full 0-255, and sony hdmi input on limited = severe black clipping on DVE test pattern
amd ccc on limited 16-235, and sony hdmi input on full = no black clipping on DVE test pattern, sony tv brightness is correct at 41
amd ccc on limited 16-235, and sony hdmi input on limited = no black clipping on DVE test pattern, sony tv brightness is correct at 51
(note 1: this is while using a normal HDMI port on the tv in cinema mode, not game or grafix mode)
(note 2: black-level/pluge comparison was made with CCC pixel format set to "limited RGB")
(note 3: the sony "auto" setting for the HDMI port seems to also correctly adapt the limited setting in this setup.
this would suggest to me that as long as the output from the pc is in limited 16-235, then our sony tv's can interpret the video signal it receives correctly (other then a change in what is the appropriate brightness level, eg 41 or 51 in my case). i suspect that the limited setting on the sony hdmi port gives a more accurate setting with its 51 brightness level, so that is what i am using now (limited CCC, and limited on sony HDMI). the "limited RGB" also seems to be the correct setting for color pixel format, instead of "full RGB" (using RGB full also slightly darkens the video image compared to using "limited RGB" i found, and some technical video articles i read recently indicated that limited RGB was the correct option for my PC blu ray player being linked to a tv via hdmi )
you stated in one of your posts that you had both pc driver output AND sony HDMI input set to "limited", yet at the same time you say you cant see the 2 upper rows of black boxes at all, which is a bit odd
i claim no expertise here
but that is how i interpret what i can observe from some of those different settings on my AMD CCC video output, and the HDMI tv input setting on my sony tv.