Originally Posted by ryandhorn
Just wanted to try and answer your second question. I'm a novice that just performed my first ever TV calibration using Calman Home for Samsung on a 55JU7500. I used a Spyder5 colorimeter, a Green-utech PL2303TA 6ft Usb Rs232 Serial to 3.5mm Stereo Aj Cable (from Amazon - for direct TV control) and Mobile Forge on a 2018 iPad Pro 12.9 (using AirPlay to my Apple TV connected to the TV to display the patterns).
I will reply to some of your questions to clear up some stuff for better end calibration results for your setup.
About your AppleTV, to be able to output correctly the required patches, it will be required some settings from CalMAN and AppleTV.
Since you are using CalMAN's MobileForge to generate patterns for a TV, you will need to setup CalMAN to work in Video Levels (16-235), then in the MobileForge tab (Middle Tab at the top of CalMAN) the 'Expand to PC Levels' box needs to be checked, because the video output will get compressed at the end.
Whatever iPhone/iPad device which CalMAN's MobileForge is driving works in PC Levels, then each device converts to Video Levels when it pipes the generated pattern through the HDMI output.
When CalMAN will send command to generate 100% White 235.235.235 RGB Triplet to MobileForge App of iPhone, the iPhone will render it as 255.255.255 (RGB-Triplet) and AppleTV (with YCbCr output selected) will be compress to video levels 235.235.235 (RGB-Triplet) or 235.128.128 (YCbCr-Triplet).
So while you send PC Level RGB triplets (0-255) at the output of AppleTV will be 16-235.
Before enabling the AirPlay Mirroring, the AppleTV video output must be set to YCbCr colorspace. On the Apple TV menu, go to Settings > Audio & Video > HDMI Output > YCbCr.
AppleTV has additional colorspace video output options, RGB-High and RGB-Low, but using any RGB selection, the incorrect conversion math of internal processing will increase even more the digital errors to the device video output.
Apple TV devices with proper settings can generate any combination for TV Video Legal (16-235), but they can't generate for TV Video Legal Extended (16-255).
This automatically means that you can't check for Clipping with Peak White (which will require to generate patches for above 235, until 255 patterns) For that reason you see 1, because its already clipped due to conversion the ATV will do to output as I describe above.
This means that you can't check your Dynamic Range with only AppleTV and MobileForge, you will need to AirPlay from iPhone or network of ATV some video patterns (no still pictures, no stuff from applications, no youtube) and then verify your Dynamic range, as the standard for Grade-1 say, you need to leave 'headroom' up to maximum bit level, so when you will look a Contrast Pattern (and a color clipping pattern) the bars should flash above 235 (it to 109% Super White) and not clip to 235 (so to flash only below 100% Reference White).
For example when you adjust for Brightness, the 1-16 Flashing Bars need to be invisible, if the user will add +5 to his TV Brightness control to be able to see 17 level (0.5% Gray) Flashing Bar, this adjustment may have lift his TV native black level, when a Brightness Pattern will be generated from an AppleTV, which will clip to 16 all 1-16 levels due to compression of levels) the user can apply an incorrect adjustment because 1-15 Flashing Bars will always be invisible.
For that reason, Contrast pattern generated from AppleTV (MobileForge) will not able to display 235-235 Flashing Bars which is required when you want to check for clipping and headroom (109% Super White) since after the compression all bars 235-254 will become 235.
Setting Contrast, Brightness and checking for Color Clipping, are considered as the initial and very important steps for any calibration.
Tyler Pruitt (Technical Evangelist for CalMAN) suggest that you will still need a calibration disk, as he posted to AVSForum.com:
You need 'headroom' because post production studios are working the movies with peak output 100 nits with full range (0-255 RGB lets say in 8-bit for example) and when the content is ready they are scalling RGB-Full to RGB-Video....(until now the all levels are inside 16-235..so max level is 235, can't be higher).....but after that the signal is encoded and compressed to delivery using YCbCr (where some pixels of RGB Video can have different levels (higher from legal levels during conversion...even encoder settings can alter the levels) after YCbCr conversion....and when you playback the movie from your player is converting the signal from YCC 4:2:0 -> YCC 4:2:2 or YCC 4:4:4 or RGB-Video and when it enters to your display its converted again (for processing.....before to enter to internal factory LUTs will be convered to RGB, for some internal calibration controls processing it will require to be performed in YCbCr) until it re-converted at the final stage to RGB to go to the panel.
So after all these conversion, add the rounding errors from processing, from multiple colorspace conversions from..... maybe the 235 will go to 236 or 237 or 238 etc....or more..
As example see these pictures below, its still pictures from a quick test using Mission Impossible - Fallout (Blu-Ray) I performed, using a special LUT which will convert whole image pixels to red/yellow/white/cyan pixels.
When you see black pictures means that these pixels are within 16-235 range, yellow when there is a grey under 16, red when there is a RGB component under 16 , Cyan when there is a grey RGB over 235 and white when there is a RGB component over 235
So when you clip your 'headroom' you see all this 'white pixels' of the above still picture clipped... while you watch these movie scenes.
Originally Posted by ryandhorn
I'd say on a scale of 1-10, 10 being the easiest, it's a 6/10 or 7/10 for a novice. The walkthrough for the software is a little off and confusing at points, though. Needs some corrections/clarification IMO. Here are my walkthrough notes:
5. Step 6 is more confusing than it needs to be, as it asks you to adjust the brightness to 15% above your target without telling you what your target should be. After research, looks like 100 is the standard peak luminance target, so 15% above that would be 115. I think the software should suggest targets for folks who don't know or understand this.
You can see the calibration standards there: Grade-1 SDR Reference Monitor/TV Calibration Targets
These are for reference viewing to a light controlled environment, for day viewing you can perform a secondary calibration with 200-300 nits, there no any standard, it has to do with about how much light you get during your during viewing from ceiling, or windows etc and how comfortable you feel.
Some rooms are OK with 200 nits others are OK with 300 nits.
The peak output for day calibration viewing as a secondary priority task, spend more time to have night viewing calibration more detailed/advanced.
Originally Posted by ryandhorn
6. Step 9 will be the hardest part for novices like me, as the walkthrough is confusing and unclear:
6a. It says to "Adjust the display's Brightness and Contrast controls to set dynamic range" but it only explains how to adjust contrast. The instructions for adjusting brightness are literally, "Click the Brightness button to display the brightness pattern then adjust brightness manually." I have no idea what that means, but it's the grey box on a black screen so I assumed I make the brightness as low as possible without the center box disappearing entirely. I'm still not 100% sure if that's right.
The gray is +2, means 2% Gray, means 20 digital level. The background is 16 (16 is the reference black). Unfortunately you can't calibrate any brightness with that pattern.
You need a pattern where it will have flashing bars below 16 and also 17 (0.5% Gray), 18, 19, 20 etc.
But when you evaluate for Brightness, while you need the 16 and below bars to be invisible (same as background) and 17 and upper to flashing, you don't want your native display black level to be increased.
Since you have a colorimeter, another way to evaluate your near black performance without loosing your native black level; and find your best Brightness setting which will not lift your black level (reduce your contrast ratio); then display any Brightness Pattern and pause when the flashing bars are visible, so it will be come static pattern.
After that place your meter at the middle left area where you see total black (bars 2-10 as example) and take a black reading with your meter with your default setting, to see your native black level, keep that number as reference....then while you adjust the Brightness slider with +1, 2, 3, 4 etc. looking the same time the bars to be visible only 17 and upper, the purpose is that your final 'correct adjustment to be the one where while you will keep your native black levels, to be able to see correctly the same time the near black details.
A lot of time, users are adjusting their brightness control looking the flashing bars of a brightness patterns, sometimes they use incorrect adjustment while trying to display 17 bar, which it can lift the black level so this will provide poorer black level and lower contrast ratio.
Originally Posted by ryandhorn
6b. For the datapoint levels drop-down, I think you have to choose "Clipping" if you're using MobileForge. It defaults to "Clipping with Peak White," but no matter what I did per the instructions, the luminance graph plateaued at 1. If what I did was correct, the CalMAN should automatically default to "Clipping" in this step since the program already knows I'm using MobileForge (made by the same company).
The summary, as explained with super detail above, using MobileForge, you can check for 'Clipping' but not for 'Clipping with Peak White'.