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Old 7th June 2014, 00:28   #1  |  Link
huhn
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Black Clipping problem

Quote:
1-Black Clipping
If madVR's "devices | <my_monitor> | properties | the display expects the following RGB output levels:" is set to "PC levels (0-255)" (default setting), the reference black bar isn't flashed while Brightness is set to 46/100. To be precise the picture doesn't change much even if I raise Brightness to max.
If this setting is set to "TV levels (16-235)" I cannot make bars 2-16 blend together even if I set Brigtness to minimum. The same result for VMR9.
3-White Clipping
"PC levels (0-255)": bar 234 is the highest flashing bar regardless of Contrast setting.
"TV levels (16-235)": bar 244 is the highest flashing bar while Contrast is set to 91/100, all bars are flashing while Contrast is set to 86/100.


Questions:

Should I set madVR to use "PC levels" or "TV levels"? "TV levels" will give me more details but I confused with this "reference black". The guide says that I should definitely not want to see any bars below reference black but why? The picture details will be loosing this way.
If I use "TV levels" what Brightness value should I use? 46/100 has no sense in this case, hasn't it?
If I use "TV levels" what Brightness value should I use? I think of 86/100 since it should give me more details than 91/100, right?


Thanks in advance for the help. AVSHD guide seems to be to complicated for me. For example I cannot understand how to use 2-APL Clipping test correctly (what to look at in this test).
looks like your display clips same black level that pretty normal they are simply created with this problem and no one usually cares. this can be fixed with a calibration.

first of all you can use custom level settings try to change the settings that only 17 and higher flash you can do this in combination with your display settings.

if the problem is still there after you have done this check the file name please in the end both should have that problem VMR and MadVR.
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Should I set madVR to use "PC levels" or "TV levels"? "TV levels" will give me more details but I confused with this "reference black". The guide says that I should definitely not want to see any bars below reference black but why? The picture details will be loosing this way.
in a video there are no infos in the 0-16 part that a simple standard this test video is full range with infos in the 0-16 part but flagged like a BD/DVD with limited to make the problem visible. a normal encode shouldn't do this so it is totally fine to remove this no it's a must for good blacks.

the rest should be answered already.
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Old 7th June 2014, 00:50   #2  |  Link
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huhn, thanks for your answer, but let's begin ab ovo though - should I use "TV levels" instead of "PC levels"? I believe it's "TV levels" but just in case.
I have tried to use custom levels. I have had set black to 2 to make bars 2-16 blend. Then I have opened a BD Remux from my collection and compared the black area of the picture with custom levels and TV levels. TV levels definitely give more details! So I'm not sure about
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a normal encode shouldn't do this so it is totally fine to remove this no it's a must for good blacks.
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the rest should be answered already
Should be but isn't. I would appreciate your kindness if you answer my questions about good Brightness and Contrast values taking into account the info I gave. Thank you again!
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Old 7th June 2014, 01:27   #3  |  Link
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Should be but isn't. I would appreciate your kindness if you answer my questions about good Brightness and Contrast values taking into account the info I gave. Thank you again!
i can't answer this i don't have your display the right settings depend on your display. everything is fine as long as 17-25 flash.

Quote:
huhn, thanks for your answer, but let's begin ab ovo though - should I use "TV levels" instead of "PC levels"? I believe it's "TV levels" but just in case.
I have tried to use custom levels. I have had set black to 2 to make bars 2-16 blend. Then I have opened a BD Remux from my collection and compared the black area of the picture with custom levels and TV levels. TV levels definitely give more details! So I'm not sure about
if only 17-25 flash with custom black 2 than this is right.
tv level shouldn't give more details the detail are just brighter or at least should be. if you aim for 100 % right settings think about a colorimeter and use that it really worth it!

if you use tv limited it's fine you lose a ton of contrast thx to this and blacks aren't black at all. but if you like it this way it's fine no detail is removed the hole picture is visible so you can do this. but this display is mean to be used as PC unlimited.

can you post a screenshoot with PC unlimited and TV limited (you have to use print screen)?

is Dynamic contrast or something like this used? if yes can you please disable it for a test. things like this can make a lot of problems.
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Old 7th June 2014, 01:53   #4  |  Link
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Originally Posted by GCRaistlin View Post
huhn, thanks for your answer, but let's begin ab ovo though - should I use "TV levels" instead of "PC levels"? I believe it's "TV levels" but just in case.
I have tried to use custom levels. I have had set black to 2 to make bars 2-16 blend. Then I have opened a BD Remux from my collection and compared the black area of the picture with custom levels and TV levels. TV levels definitely give more details! So I'm not sure about
As huhn stated, it sounds like your TV is crushing blacks, this is very common in my experience. Again reiterating huhn; MadVR should be set to output PC levels if you can get your TV to handle it correctly (full range input), from your description your's does except for the slightly crushed blacks. Calibrating to BT.1886 should fix that and restore the lost shadow detail using PC levels without raising the black level, no one likes gray blacks.

If you have everything set correctly there should not be an obvious difference in shadow detail using PC or TV levels, you need to change other settings if you change between them to compensate for their differences. If you see a lot more shadow detail using TV levels you probably raised the black level until it was significantly above where your TV clips; this is very bad IMHO as a low black level is one of the most important aspects of a good TV. I prefer slightly crushed blacks to a raised black level if you cannot calibrate.

I don't think anyone can accurately answer your questions about brightness/contrast without having experience with your TV, which TV make and model is it?

Quick and dirty; with brightness at a "reasonable midpoint" raise contrast as high as you can and still see bar 234 then raise brightness as high as you can and still see bar 17. Then check that you can still see both 234 and 17. This is not correct on a lot of TVs as brightness and contrast can mean different things on different displays.

If you do not want max brightness you can set brightness as desired and then raise contrast as described. Sometimes the picture starts to go weird as you raise contrast but bar 234 is still visible, in that case you should lower contrast below the "weird" threshold.

Last edited by Asmodian; 7th June 2014 at 01:59.
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Old 7th June 2014, 15:35   #5  |  Link
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My monitor is ASUS VS229 (IPS) connected via DVI.
As far as I understand the biggest issue with using TV levels is gray instead of black, but on the other hand you'll get all details of the picture - on an uncalibrated monitor. I don't know as for others but in my case I definitely prefer more details than "honest black":
http://i57.tinypic.com/2dlrj9x.jpg
http://i59.tinypic.com/6q9o95.jpg

Quote:
is Dynamic contrast or something like this used?
No.

Quote:
rom your description your's does except for the slightly crushed blacks. Calibrating to BT.1886 should fix that
But the calibrator is required for this, right?
The calibration process consists of changing R, G, B, Brightness and Contrast values? What do you think about software monitor customize tools like CLTest? The guide says that test image should look "gray, without squares" from far distance - on my display it looks like this from ~2 meter:

I don't really understand if any "squares" that should not be presented are present in my case. No I do see squares but I cannot imagine that they can blend on this picture somehow!

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with brightness at a "reasonable midpoint"
What is "reasonable midpoint" of brightness?

Quote:
raise contrast as high as you can and still see bar 234 then raise brightness as high as you can and still see bar 17.
As I wrote I am able only to find right Contrast value by which I see bar 234 flashing. But I could barely see bar 17 flashing at any Contrast level higher than 46/100 (I cannot see bar 16 by Contrast 100/100).
Bar 17 and above blend with the background when Contrast is lower than 46/100.
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Old 7th June 2014, 15:55   #6  |  Link
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Stare at the sharpness test image's center without blinking for a moment, or squint your eyes. On my monitor and TV I only see the black and white rectangles on a smooth grey background after a while.

Oh and it really is sharpness test, I don't think I ever used that image when I tried to calibrate the colours by eye. I have sharpness set to zero on both devices.

Last edited by YxP; 7th June 2014 at 16:02.
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Old 7th June 2014, 16:00   #7  |  Link
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Originally Posted by YxP View Post
Stare at the sharpness test image's center without blinking for a moment, or squint your eyes. On my monitor and TV I only see the black and white rectangles on a smooth grey background after a while.
Oh so that was meaned? That we should see rectangles, not squares? Thank you.
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Old 7th June 2014, 16:24   #8  |  Link
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Quote:
I am able only to find right Contrast value by which I see bar 234 flashing.
I was wrong. 234 is the highest flashing bar regardless of Contrast value.
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Old 7th June 2014, 16:27   #9  |  Link
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Should I choose sRGB preset in monitor settings? As per CLTest guide, it's one of the possible start point of monitor customizing - either sRGB preset or Standard preset. But in case of sRGB Brightness and Contrast are disabled in the monitor menu.
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Old 7th June 2014, 18:03   #10  |  Link
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If you don't have a colorimeter, the best you can do is follow instructions on http://www.lagom.nl/lcd-test/. Or at least that's what I did before I managed to borrow one
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Old 8th June 2014, 00:48   #11  |  Link
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YxP, thanks for the link! I've discovered that sharpness level in Normal mode (that's what I always started from when customizing my monitor) was too high and, what is more, locked for some reason that is known only to ASUS. Also, gamma calibration result confuses me - I'm able to adjust curves for each channel to make them blend at 2.2 (48% bars) but then gray 48% bar blends at ~1.7. So I don't know what to choose - to adjust "all leves" curve and make gray bar blend at 2.2 (but then color bars won't blend at 2.2) or to adjust each channel separately. White saturation test isn't passed completely - I can't see patterns 253 and 254 regardless of the monitor settings. All other things seem to be OK: contrast, sharpness, black level.
But TV levels still gives better result (more details on dark scenes) than PC levels or custom levels (4-254, according to 1-Black Clipping and 3-White Clipping tests result). Can you guys please check TV levels on your well-calibrated monitors? Won't they give more details than PC levels? I'm just curious.
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Old 8th June 2014, 01:17   #12  |  Link
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detail are just brighter and easier to spot at tv level but i don't lose them at pc level.
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Old 8th June 2014, 07:42   #13  |  Link
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Can you guys please check TV levels on your well-calibrated monitors? Won't they give more details than PC levels? I'm just curious.
Absolutely not, if calibrated to BT.1886 with PC levels changing to TV levels gives a much worse contrast. Shadow detail does become more obvious as moving up the the gamma curve has larger differences between steps but this is not how the video was meant to be viewed. If you cannot tell the difference between bar 16 and 17 you lose shadow detail. If you can see bar 16 than you have a raised black level. After calibration I can see bar 17 but not 16.

If I switch to TV levels and recalibrate there is no difference in shadow detail or black level in madVR. The only obvious change is that the desktop has clipped blacks and whites. Calibration is like that.
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Old 8th June 2014, 09:42   #14  |  Link
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After calibration I can see bar 17 but not 16.
That's what I can see too but I lose details in real movies by that.

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If I switch to TV levels and recalibrate there is no difference in shadow detail or black level in madVR. The only obvious change is that the desktop has clipped blacks and whites. Calibration is like that.
No I mean try TV levels on non-recalibrated monitor and make comparison screenshots of the whole screen like I did for a dark scene of a movie. Please if it won't disturb you much.
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Old 8th June 2014, 14:02   #15  |  Link
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you have problems in seeing detail in dark scene with custom pc level and flashing 17-25 right?

you can chance the gamma by setting MadVR to this display is already calibrated at calibration and set a lower gamma in color & gamma use pure power cure.

this makes dark scene more bright without rising the black level like TV level does.

normally you want something like 2.4 in a dark room but in a well lit room even 1.8 can be right.
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Old 9th June 2014, 00:18   #16  |  Link
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Thanks, huhn. It seems that I have finally customized my monitor in the right way 'cause now I don't see more details with TV levels and even with gamma correction. Also, I don't see lack of details in madVR screenshots I have posted as examples to the topic before. Thanks a lot again!
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Old 9th June 2014, 00:26   #17  |  Link
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Also, I wish to thank Asmodian and YxP!
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Old 9th June 2014, 13:46   #18  |  Link
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Should I use custom levels if I cannot see pattern 254 in White Saturation test?
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Old 9th June 2014, 15:09   #19  |  Link
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yes.
but it's a unlimited png so i don't know if that's really important
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Old 9th June 2014, 15:14   #20  |  Link
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What level values should I use in this case?
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