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Old 12-13-2009, 02:05 PM - Thread Starter
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I just bought an LG 47SL90 about two weeks ago. I've got it pretty settled down now in terms of settings so I am thinking about things like calibration. A little over a year ago I purchased the i1 Display2 colorimeter to calibrate my computer monitors because I shoot digital photography. I was thinking with this colorimeter I could have a go at calibrating the TV as well.

I have a DVI-HDMI cable I can use to connect the TV to my Mac laptop. When I did that I connected my colorimeter to the laptop and calibrated the display as if it were a second monitor. A hidden bonus of this was that once I dialed in the correct D65 whitepoint using the RGB controls on the TV, there was an option to copy this white point setting to all inputs. So I presume that the white point has been correctly set for all inputs now. Also I was able to tune in the brightness (I chose 120cd/m2) and if I just use the same backlight level for all inputs the brightness will be consistent as well. Now as I understand it, however, the TV when calibrated as a secondary display off the laptop relies on the .icc profile created on the laptop and therefore will only correct color when it is connected via the laptop (i.e. the icc profile is tied to the computer and not loaded onto the TV).

My question is, how do you accomplish calibration on the TV so that it is independent of source? I read through the stickied thread at the top and did some fiddling with HCFR and I think I have it understood except one missing piece. I found with HCFR I could measure the properties of a certain display, but as the computer has no way to talk to the TV in this case, how do you actually affect changes to the TV's display in order to correct any deviations? Do you basically just need to measure for example one primary and then fiddle the settings on the TV and then measure again and repeat until you have it right? Or is there some systematic way of going about it that I have not picked up on?

Also, how do you measure and correct for the gamma ramps? My LG TV has controls for color and tint for each the primary RGB and secondary CYM colors but not for example a gamma or something.

Lastly, the display seems to be set up pretty good from the factory? For example, I used the TV's built in blue filter to go through the THX optimizer and at the default settings the color/tint test screen was uniformly blue. Extending on this I downloaded the HD test screens from the forums and copied them to USB drive where I attached it to my xbox 360 and looked. That one test with the flashing bars of red, green, and blue (overlaid with the secondaries) where you can do the similar test to the THX optimizer (except with all 3 colors, using the built-in RGB filters in my TV) and when I do this these colors too all appear to be correctly set (you can barely distinguish the flashing colors when the appropriate filter is used). Also if I look at the brightness test screens I can see all the shades within the 16-235 zone and the brightness and contrast set to was out beyond that. The 1080p test patterns showed 1:1 pixel mapping, etc. basically every "eyeball" test I looked at from those HD test screens I could not really improve upon by changing away from the default settings. Does that mean that my TV is pretty much spot on anyways, and that color correcting with the CMS will yield only very subtle results?

Thanks for looking and for helping a newcomer out!

Ruahrc
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Old 12-13-2009, 05:09 PM
 
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My question is, how do you accomplish calibration on the TV so that it is independent of source? I read through the stickied thread at the top and did some fiddling with HCFR and I think I have it understood except one missing piece. I found with HCFR I could measure the properties of a certain display, but as the computer has no way to talk to the TV in this case, how do you actually affect changes to the TV's display in order to correct any deviations? Do you basically just need to measure for example one primary and then fiddle the settings on the TV and then measure again and repeat until you have it right? Or is there some systematic way of going about it that I have not picked up on?

Yup. You measure and adjust it to be where it needs to be. You'll want to start with the greyscale most likely righ the RGB gains/cuts.

I'm not familiar with LG at all, so I have no idea what the CMS capabilities of this display is, or whether it works properly. Someone else may chime in.
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Old 12-13-2009, 05:39 PM
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Quote:
Originally Posted by Ruahrc View Post

I just bought an LG 47SL90 about two weeks ago. I've got it pretty settled down now in terms of settings so I am thinking about things like calibration. A little over a year ago I purchased the i1 Display2 colorimeter to calibrate my computer monitors because I shoot digital photography. I was thinking with this colorimeter I could have a go at calibrating the TV as well.

I have a DVI-HDMI cable I can use to connect the TV to my Mac laptop. When I did that I connected my colorimeter to the laptop and calibrated the display as if it were a second monitor. A hidden bonus of this was that once I dialed in the correct D65 whitepoint using the RGB controls on the TV, there was an option to copy this white point setting to all inputs. So I presume that the white point has been correctly set for all inputs now. Also I was able to tune in the brightness (I chose 120cd/m2) and if I just use the same backlight level for all inputs the brightness will be consistent as well. Now as I understand it, however, the TV when calibrated as a secondary display off the laptop relies on the .icc profile created on the laptop and therefore will only correct color when it is connected via the laptop (i.e. the icc profile is tied to the computer and not loaded onto the TV).

My question is, how do you accomplish calibration on the TV so that it is independent of source? I read through the stickied thread at the top and did some fiddling with HCFR and I think I have it understood except one missing piece. I found with HCFR I could measure the properties of a certain display, but as the computer has no way to talk to the TV in this case, how do you actually affect changes to the TV's display in order to correct any deviations? Do you basically just need to measure for example one primary and then fiddle the settings on the TV and then measure again and repeat until you have it right? Or is there some systematic way of going about it that I have not picked up on?

Also, how do you measure and correct for the gamma ramps? My LG TV has controls for color and tint for each the primary RGB and secondary CYM colors but not for example a gamma or something.

Lastly, the display seems to be set up pretty good from the factory? For example, I used the TV's built in blue filter to go through the THX optimizer and at the default settings the color/tint test screen was uniformly blue. Extending on this I downloaded the HD test screens from the forums and copied them to USB drive where I attached it to my xbox 360 and looked. That one test with the flashing bars of red, green, and blue (overlaid with the secondaries) where you can do the similar test to the THX optimizer (except with all 3 colors, using the built-in RGB filters in my TV) and when I do this these colors too all appear to be correctly set (you can barely distinguish the flashing colors when the appropriate filter is used). Also if I look at the brightness test screens I can see all the shades within the 16-235 zone and the brightness and contrast set to was out beyond that. The 1080p test patterns showed 1:1 pixel mapping, etc. basically every "eyeball" test I looked at from those HD test screens I could not really improve upon by changing away from the default settings. Does that mean that my TV is pretty much spot on anyways, and that color correcting with the CMS will yield only very subtle results?

Thanks for looking and for helping a newcomer out!

Ruahrc

Since you have a LED-backlit (or LED-edgelit to be exact in your case) LCD, the eye one display will not be too accurate with your TV, meaning that you may end up with no real improvement or end up making things worse depending on how accurate your grayscale is to begin with. Also, CMS and color work in general are beyond the capabilities of your meter as well meaning that you can't really trust what color readings for primaries and secondaries you get from the eye one display. A chroma 5 with calibration tables for LED displays would be the minimum and the eye one pro might be a better choice should CMS work be critical to you.
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Old 12-13-2009, 06:20 PM - Thread Starter
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How does LED illumination interfere with the Display2's ability to calibrate?

And I had heard that although the Display2 is certainly not the end-all of colorimeters, that it was by far and away the most accurate color calibrator in its price range (i.e. you need to spend >$500 to get anything meaningfully better). Is this not the case? For my needs (getting accurate colors from my monitor so that when I print my photos the output matches the screen) it serves wonderfully. Just gravy on the top if it can help my TV out as well.

Your point stands though as in that since I am not making ads for Coca-Cola, where getting the exact red is live or die, I'm not going to spend any more money on calibration, treat it instead of more like a weekend project to fiddle around with.

Ruahrc
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Old 12-13-2009, 06:37 PM
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Quote:
Originally Posted by Ruahrc View Post

How does LED illumination interfere with the Display2's ability to calibrate?

And I had heard that although the Display2 is certainly not the end-all of colorimeters, that it was by far and away the most accurate color calibrator in its price range (i.e. you need to spend >$500 to get anything meaningfully better). Is this not the case? For my needs (getting accurate colors from my monitor so that when I print my photos the output matches the screen) it serves wonderfully. Just gravy on the top if it can help my TV out as well.

Your point stands though as in that since I am not making ads for Coca-Cola, where getting the exact red is live or die, I'm not going to spend any more money on calibration, treat it instead of more like a weekend project to fiddle around with.

Ruahrc

"Note that some new LED based displays can pose challenges for the EyeOne Display 2/LT (it does not matter if it is a edgelit, backlit or backlit RGB). The least expensive meter that can and does work correctly with LED displays is Chroma 5 that has been specially backlit LED calibrated for use with CalMAN (see below). The EyeOne Pro is also a good choice."

http://www.curtpalme.com/forum/viewtopic.php?t=11436
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Old 12-13-2009, 07:24 PM
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Originally Posted by ChrisWiggles View Post

Yup. You measure and adjust it to be where it needs to be. You'll want to start with the greyscale most likely righ the RGB gains/cuts.

I'm not familiar with LG at all, so I have no idea what the CMS capabilities of this display is, or whether it works properly. Someone else may chime in.

If it's like the LG LH90, there's level and hue for each primary and secondary.
It works pretty well if you leave the main color and tint at defaults for the ISF expert1 and 2 modes and work from there.
Don't go overboard trying to get the red hue perfect; it's a little wide and the temptation is to pull the hue way over to yellow/green. It won't get perfect. But a little (0-8 points out of a possible 30) pull toward yellow/green on the red primary and then evening out the level will give beautiful skin tones.
And the yellow level control doesn't work right (it desaturates instead of decreasing level), so just leave yellow's level where it is- it's not far off any way.

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Old 12-15-2009, 01:31 PM - Thread Starter
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Originally Posted by PlasmaPZ80U View Post

"Note that some new LED based displays can pose challenges for the EyeOne Display 2/LT (it does not matter if it is a edgelit, backlit or backlit RGB). The least expensive meter that can and does work correctly with LED displays is Chroma 5 that has been specially backlit LED calibrated for use with CalMAN (see below). The EyeOne Pro is also a good choice."

http://www.curtpalme.com/forum/viewtopic.php?t=11436

Also found this from the Xrite website:

"In house testing has demonstrated that LED backlit displays can be successfully calibrated and profiled using both colorimeters (i1Display 2, i1Display LT2) and spectrophotometers (i1Pro, ColorMunki Photo instruments)."

http://www.xritephoto.com/ph_learnin...ortID=4981#tip

Who to believe?

Anyways I'll give it a go when I get some time and see how it measures up. Seems like the SL90's color controls are the same as the LH90 (the manual that came with the SL90 seems to be generalized to all the current LG models). It's handy to have 2 "expert" modes to work on I can leave the current settings in Expert1 and then do the fiddling in Expert2.
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Old 12-15-2009, 01:47 PM
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What do you need?

Depends on the level of accuracy you require.

My all means go to town with your display2. If you feel like you want more accuracy then a chroma5 with an LED table would be the next step in accuracy.

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Old 12-15-2009, 01:51 PM
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Problem with colorimeters is that their filters only approximate the spectral response of the CIE standard observer (color matching functions). For spectrally broad measurements this is not so much of a problem, but for spectrally narrow measurements (like LED backlights) there is increased error. You can get around this by creating a special calibration for the colorimeter that is specific to the display being measured. It is essentially a 3x3 matrix. This is what x-rite does for the i1d2 they package in the HP LP2480zx calibration kit. It is not a standard i1d2 but has been matched to the primaries of the display. Similarly, ARRI resells the x-rite hubble to post production houses (mostly in Europe). It has 14 different slots for device specific calibration matrices to improve its accuracy and is supplied to the customer with presets for some of the typical displays you would find in a post house.

There are very high-end colorimeters that use several filters to get a very close match to the CIE standard, but these are very expensive. LMT is one such source for these (http://www.lmt-berlin.de).

So the answer is a standard colorimeter can work for LED displays if it has been calibrated to the primaries of that display. Off-the-shelf, it will not give accurate readings.
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Old 12-15-2009, 02:50 PM
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Quote:
Originally Posted by Chad B View Post

If it's like the LG LH90, there's level and hue for each primary and secondary.
It works pretty well if you leave the main color and tint at defaults for the ISF expert1 and 2 modes and work from there.
Don't go overboard trying to get the red hue perfect; it's a little wide and the temptation is to pull the hue way over to yellow/green. It won't get perfect. But a little (0-8 points out of a possible 30) pull toward yellow/green on the red primary and then evening out the level will give beautiful skin tones.
And the yellow level control doesn't work right (it desaturates instead of decreasing level), so just leave yellow's level where it is- it's not far off any way.

Chad, what's your take on whether an i1d2 is good enough to calibrate LED displays? It seems there are two sides to the issue but I'm leaning to the side that an uncorrected colorimeter is not reliable for LED technology.
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Old 12-15-2009, 07:22 PM
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Originally Posted by PlasmaPZ80U View Post

Chad, what's your take on whether an i1d2 is good enough to calibrate LED displays? It seems there are two sides to the issue but I'm leaning to the side that an uncorrected colorimeter is not reliable for LED technology.

I don't own an i1d2, so I can't say from experience. But like you, based on the above posts, I would not be too hopeful.
I own 2 Spyder2s, a Milori Trichromat-1 (aka Sencore CP-III), 2 i1 Pros, and an Enhanced C5. The Spyder2s are so horrible without profiling I don't like them on anything; and even when I profile them off the i1 Pro they seem suspect. The Trichromat is a nice meter, but it's not accurate with LCDs of any type, whether for grayscale or CMS. My Enhanced C5, after my latest testing, seems accurate with LED LCDs after an initial meter warmup period.

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Old 12-15-2009, 10:58 PM - Thread Starter
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Well I took my PC from my room and hooked it up in the room where my TV is so that I could fiddle with the colorimeter today. I don't have a windows laptop and unfortunately the Mac version of HCFR does not do the EyeOne, so I had to pull the PC out.

Anyways, here is the results I got. Assuming the meter is accurate with LEDs, I was impressed with how well the display measured up with completely neutral settings (ISF Expert mode, everything zeroed out). After following the calibration steps from this thread I was able to get the results even better (again, assuming the meter is accurate). Qualitatively it seems like the screen is a bit clearer now and I am happy with the result. I will stick with the settings for now and just leave it at that.

Here are some pictures of the before or stock condition:








Notice that the red primary is basically spot on, with no correction. Green is a little wide (was even wider with the TV on wide gamut setting) and blue is a little off but pretty close. All the white values fell within 10 dE except for I think the 10% IRE which was a little off. The luminance tracking seemed pretty impressive to me (especially considering the sample graphs in the directions!)

After calibrating the greyscale and RGBYCM colors here is the result. I was able to handle in the RGB levels and get all the luminance values to a dE of less than 2. Some minor tweaks to the primary/secondary colors (was not able to completely fix the blue and by extension the magenta) and the results at least theoretically are looking very good.









The gamma somehow got worse at the top end I'm not exactly sure why. But the total differences seem to be very minor from the before to the after condition.

In all a fun experiment and I'm quite happy with the display quality. Looks like this is about as good as I will be able to get it given my current equipment and it's plenty good for my needs. Heck I use the TV mainly for gaming anyways . Sorry about all the pics for those on a slow connection.

Ruahrc
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Old 12-29-2009, 06:54 AM
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Hey I am new to the forums I was wondering if you could post up the settings that worked for you? I just cant get my 47sl90 to look decent at all! Please help! Thank you!
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Old 01-05-2010, 07:56 PM
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Hey,

I'm a new poster too. Just recently got the SL90. I like it but can't seem to get the settings quite right. I don't really have the equipment to do all the calibrations but if you could post some sample settings that you used, that would be aces! Thanks for any help in advance.
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Old 01-23-2010, 06:14 PM
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