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Prior to doing a Calman home LG calibration on a 77CX should I do a brightness and contrast calibration for SDR, HDR or DV? Or is this completely unnecessary?
 

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Yes, for SDR only. HDR and DoVi generally run the display at full throttle to meet the ST2084 luminance curve. Their tone mapping is based on the default contrast and brightness settings and these should not be changed.
 

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Yes, for SDR only. HDR and DoVi generally run the display at full throttle to meet the ST2084 luminance curve. Their tone mapping is based on the default contrast and brightness settings and these should not be changed.
What is the best pattern to use for SDR? Any settings I should start with for contrast and brightness?
 

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You can use black clipping and white clipping patterns in SDR to set brightness and contrast, respectively. With the brightness pattern, you are making sure you cannot see flashing on the bars with values of 16 and below. With the contrast pattern, you are looking for either flashing from 235 up to 255, or no flashing above 235 (there are two schools of thought on this, and it's your choice). In either case, there should be no color shift or tinting at or above White. If there is, it can indicate color clipping, and you need to reduce contrast until it goes away. These patterns really should be from a disc out of a standalone player to ensure correct level matching between the source and display.
 

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You can use black clipping and white clipping patterns in SDR to set brightness and contrast, respectively. With the brightness pattern, you are making sure you cannot see flashing on the bars with values of 16 and below. With the contrast pattern, you are looking for either flashing from 235 up to 255, or no flashing above 235 (there are two schools of thought on this, and it's your choice). In either case, there should be no color shift or tinting at or above White. If there is, it can indicate color clipping, and you need to reduce contrast until it goes away. These patterns really should be from a disc out of a standalone player to ensure correct level matching between the source and display.
Dont these setting just get overwritten when you update the SDR table files to the TV through Calman? Or does the contrast and brightness setting remain unchanged?
 

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CalMAN will read your Black and White results and use them to compute targets for gamma, grayscale, and colors. Unless you have told it to use fixed values...
 

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CalMAN will read your Black and White results and use them to compute targets for gamma, grayscale, and colors. Unless you have told it to use fixed values...
I set the Power to Gamma 2.2 for day and 2.4 for night. Is that what you are referring too as fixed values?
 

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Nope. You can specify in the Workflow settings whether to use the values CalMAN reads for Black and White, or to use the fixed Black and White values you type in there.
 

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2. HDR10 and DV do not let you state a target luminance as does SDR. SDR's luminance targets are a suggestion, while luminance targets for HDR10 and DV are absolutes, following the ST2084 EOTF luminance curves. All current TVs have to run at full throttle in HDR modes since they cannot meet the ST2084 requirements, so you aren't given any choice.

You should be using the AVS HD 709 on disc when setting brightness and contrast to avoid levels mismatches.
Thanks for your reply, but now I am even more confused :) I was under the impression that I chose luminance based on the view condition? So if I'm in a dark room, I should choose about 100cd/m2, and while I'm in a lit room, I should choose 200cd/m2 or more, depending on how lit the room is - because the brightness of the room will affect if I am able to see the details in the black areas of the image (like that black bars in AVS HD 709).

And, do you mean I should set brightness and contrast, using AVS HD 709, before using CalMan? Is it not the point of CalMan to do this automatically, since it's a calibration tool with a meter and patterns?
 

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You only choose target luminance for SDR. In reality, "normal" HDR is intended for low light viewing, as its average background picture luminance is roughly 100-200 nits, the same as recommended for SDR. All the other luminance it can generate is reserved for specular highlights. Again, HDR modes are generally run at full contrast and backlight (or OLED light) to generate maximum luminance, and a default brightness, not giving you much room for maneuver.

And yes, in SDR, you should set brightness and contrast before using CalMAN. For one thing, your meter cannot "see" true black, as there is nothing there for it to measure. Your eye, however, can see the black in a black clipping pattern by comparing the bars that are supposed to be black to the background, which is also black. A meter cannot do that, as it reads only a spot. The same goes with the white clipping pattern. CalMAN will not do this for you.

I strongly suggest you check out this link:
Although it has details of another software package, it covers basics you should know about when calibrating, even when doing an "autocalibration". Note that I am not advocating the other software. It's just a very comprehensive guide to basic calibration and has in fact been rewritten over the years to feature other software, including CalMAN.
 

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1. When I display the "Black clipping"-clip from AVS HD 709, I can barely see bar 19 blinking, and nothing below. Does that mean I should raise the OLED light when asked in the calibration, so I can see bar 17 blink (but not 16)?
OLED Light is not the correct control for adjusting black level. OLED Light changes the overall luminance range and shouldn't alter/compromise the black level. It's similar to changing how bright the backlight is on LCD display. Brightness is normally the correct setting to use to adjust black level. Are you observing the black clipping pattern in a completely dark environment? Other light in the environment can make near black difficult to see. You may also be experiencing the intermittent black level offset that several with the C-Z9 have been experiencing with software version 05.00.03. The same may be occurring with software version 05.00.02 for the B9. With earlier versions of the software, the black level for SDR post autocal was very near ideal with the default brightness and contrast settings (at least on my set). Unfortunately for the calibration to be technically correct and valid when using the custom 1D LUT (Calman grayscale AutoCal), the Brightness and Contrast controls need to remain at their default settings of 50 and 85 (for SDR). Changing Brightness and Contrast from those default values alters the the video data being input to the 1D LUT, and the LUT is built with the expectation that the video data coming into the LUT is unaltered.

2. When I calibrate for HDR and DV, I do not get any questions about luminescence? Why not? Are the HDR and DV calibrations dependent on a proper SDR calibration beforehand, or is there some other magic? Or, the other way around: Why does the SDR calibration ask me about luminance/OLED Light, when HDR and DV does not?
The accepted standards of peak brightness for SDR are well below the maximum capability of our HDR televisions. In that case are using the OLED light setting to reduce to a desired peak luminance (such as 100 nits). The video range for HDR and DV have defined brightness ranges that extend well beyond the capability of our TVs, so we are not attempting to limit that range to a desired peak luminance that is less than the capability of the TV using the OLED Light setting. Instead we leave it at its maximum setting.

3. There is alot of talk about crushed blacks. What exactly do you/they mean? When I watch TV, and the presenter has a black suit, and I feel it's to dark and I can't see the details, is that what you talk about?
In general, yes. In most cases for the context of discussion in this forum, it is basically what you are asking about in question 1, with some amount of above black information (8-bit video levels 17, 18, 19, etc.) being output exactly the same as and indiscernible from true black (16).
 

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OLED Light is not the correct control for adjusting black level. OLED Light changes the overall luminance range and shouldn't alter/compromise the black level. It's similar to changing how bright the backlight is on LCD display. Brightness is normally the correct setting to use to adjust black level. Are you observing the black clipping pattern in a completely dark environment? Other light in the environment can make near black difficult to see. You may also be experiencing the intermittent black level offset that several with the C-Z9 have been experiencing with software version 05.00.03. The same may be occurring with software version 05.00.02 for the B9. With earlier versions of the software, the black level for SDR post autocal was very near ideal with the default brightness and contrast settings (at least on my set). Unfortunately for the calibration to be technically correct and valid when using the custom 1D LUT (Calman grayscale AutoCal), the Brightness and Contrast controls need to remain at their default settings of 50 and 85 (for SDR). Changing Brightness and Contrast from those default values alters the the video data being input to the 1D LUT, and the LUT is built with the expectation that the video data coming into the LUT is unaltered.


The accepted standards of peak brightness for SDR are well below the maximum capability of our HDR televisions. In that case are using the OLED light setting to reduce to a desired peak luminance (such as 100 nits). The video range for HDR and DV have defined brightness ranges that extend well beyond the capability of our TVs, so we are not attempting to limit that range to a desired peak luminance that is less than the capability of the TV using the OLED Light setting. Instead we leave it at its maximum setting.


In general, yes. In most cases for the context of discussion in this forum, it is basically what you are asking about in question 1, with some amount of above black information (8-bit video levels 17, 18, 19, etc.) being output exactly the same as and indiscernible from true black (16).
Is the Black clipping that is happening right now with the current firmware affected by Auto-Cal or does it happen whether or not it’s calibrated?


Sent from my iPhone using Tapatalk
 

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Is the Black clipping that is happening right now with the current firmware affected by Auto-Cal or does it happen whether or not it’s calibrated?
I haven't evaluated it myself on un-calibrated picture modes, but from what others have reported it affects them as well. On my C9 the black level is lower when un-calibrated anyway. With earlier software I needed Brightness 52 for accurate black level on uncalibrated ISF Expert Dark and Technicolor Expert modes. An even higher Brightness setting should be needed if/when the black clipping is affecting uncalibrated SDR picture modes.
 

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Is it normal (and safe?) to see minor image retention from displaying patches during an SDR autocal? Calibrating my bright room PM @ 210 nits and am noticing minor retention on my 15% grey pattern insertion screen. 30 / 5 / 15 are my pattern insertion settings.

I have noticed this too with SDR dark room calibration @100nits, however I was using the less aggressive default pattern insertion settings then.
 

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Is it normal (and safe?) to see minor image retention from displaying patches during an SDR autocal? Calibrating my bright room PM @ 210 nits and am noticing minor retention on my 15% grey pattern insertion screen. 30 / 5 / 15 are my pattern insertion settings.

I have noticed this too with SDR dark room calibration @100nits, however I was using the less aggressive default pattern insertion settings then.
Normal.
 

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CalMAN will read your Black and White results and use them to compute targets for gamma, grayscale, and colors. Unless you have told it to use fixed values...
Nope. You can specify in the Workflow settings whether to use the values CalMAN reads for Black and White, or to use the fixed Black and White values you type in there.
I've found very little information explaining the "Target Options" settings in CalMAN, but I'm understanding them a bit differently than what I think you're describing. My descriptions below are meant in context of SDR.

First, I believe that making settings to Brightness and Contrast before beginning an Autocal with CalMAN is ineffective, because those settings actually are reset to the defaults of 50 and 85 when the calibration begins (after the pre-cal measurements). They need to be at these settings for the incoming video signals to be fed into the 1D LUT unaltered (all video data values matching and being fed directly to their respective input values in the Look Up Table). Setting the LUTs to unity further passes these video data values through unaltered (LUT input equals LUT output) so that the display is essentially driven directly by the unaltered incoming video data.

I don't think that "Use Measured Black Level" results in CalMAN reading anything about a brightness or black level setting that you previously made. It simply takes the meter reading that results when a completely black (10-bit 64,64,64) patch is displayed on screen (with unity LUTs, and native/bypass settings) and uses it for the bottom of the gamma curve. An emissive display such as our OLEDs should have zero light output in this case. Since most or all consumer meters can't read this (my i1d3 reports some default minuscule light output), I prefer to manually enter 0.0 cd/m2 so that the gamma curve is based upon what the display is actually doing (or should be doing) rather than the limits of the meter. A backlit display will have some light output at reference black, which I think is a legitimate reason to "Use Measured Black Level." That will make the measured black level the bottom of the gamma curve and avoid targeting near black at or below the minimum light output of the display. I believe having an accurate measured black level (when it is non-zero) is also necessary for correct plotting of BT.1886.

"Include black in AutoCal Adjustments" is a mystery to me. The option is apparently only applicable to manually entered black level targets and to not ones measured with a meter. The gamma curve seems to be adjusted to the manually entered value whether this option is selected or not.

"Use Measured White Level" uses whatever the meter measures from a reference white patch (10-bit 940,940,940) as the top end of the gamma curve. I believe that entering a manual value here both results in that value being used for the top end of the gamma curve, and the 1D LUT limiting the 100% reference luminance to that target. I think selecting "Use Measured White Level" in combination with using the OLED Light setting to target 100% luminance is preferable for our LGs because it avoids the LUT reducing the dynamic range of the video signal.
 
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I have a stupid question: when you calibrate for a HDMI port, is it calibrated for the others at the same time or do we have to calibrate for each hdmi port on the TV?
 

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I have a stupid question: when you calibrate for a HDMI port, is it calibrated for the others at the same time or do we have to calibrate for each hdmi port on the TV?
When you calibrate, you calibrate for the picture setting only for the input you are currently using. It is only applied to all inputs if you click on "apply to all inputs" on the picture mode settings IIRC.

So for example, if you want your ISF Dark calibration to apply for all inputs, you calibrate one input and then choose apply to all inputs. If you only want a couple HDMI ports calibrated, then you have to do the calibration once on each input.
 
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