LG 2017 OLED Calibration Thread and Settings - Page 40 - AVS Forum | Home Theater Discussions And Reviews
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post #1171 of 3197 Old 12-02-2017, 04:46 PM
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85 is absolutely the correct contrast setting.
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post #1172 of 3197 Old 12-02-2017, 05:23 PM
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Question for the professional calibrators, does the CMS introduce artifacts when used?


Should CMS be completely avoided? Know it introduced artifacts in 2016 OLEDs. Have heard conflicting info about 2017s.
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post #1173 of 3197 Old 12-02-2017, 06:35 PM
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55C7P

Question - so I have my Comcast box and my ATV 4K both direct to the TV via HDMI. The ultra HD Belkin cables. Audio is fine, out through optical. When watching football, though - the picture is fantastic in any close-up or medium shots. As soon as the camera pulls out, though, the whites start washing out, and the picture is not as clear.

I've tried various presets, used the Cable box as well as the respective ATV apps (Fox Sports, CBS, etc.), and I get the same results. It's not just for high-motion sequences. On the cable box side, I've tried with both 720 and 1080, trying to see if the TV would do a better job with that.

Are there any specific settings that I should look to tweak for this symptom?
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post #1174 of 3197 Old 12-02-2017, 10:19 PM
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Quote:
Originally Posted by PeteNeat View Post
^One is fighting against the other. Try OLED 40. Also WOW was released well before OLED tech so I would take what it advises with a pinch of salt.
Maybe you mean Brightness? The Oled Light setting has no effect on the white and black level tests, at least in terms of what's visible. Even if I set the Oled to 100, I still need to crank the contrast to 97 to get a picture that is considered ideal according to WoW. Now Brightness on the other hand does affect the white clipping test, but I would need to set it around 70 or so in order to allow me to lower the contrast to the 80's. But raising the brightness that high messes with the black levels. The correct brightness level seems to be 52 for me.

So I end up with these settings:

Brightness 52
Contrast 97
Oled Light doesn't matter, but I like it around 25-30

edit: It sounds like the Oled Light was changed in the 2017 models (skip to 8:44):
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post #1175 of 3197 Old 12-03-2017, 12:59 AM
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Originally Posted by WiFi-Spy View Post
85 is absolutely the correct contrast setting.
Can you explain why the goal shouldn't be to turn contrast up until 235 (reference white) is just below peak value?

Hmmm... maybe this has to do with my TV receiving limited RGB instead of full? (which I think is the case because the black level needs to be set on "low")

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post #1176 of 3197 Old 12-03-2017, 07:40 AM
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^^^
If you raise the contrast above 85 the set will start to clip white severely.

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post #1177 of 3197 Old 12-03-2017, 07:59 AM
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Quote:
Originally Posted by Venomous21 View Post
Question for the professional calibrators, does the CMS introduce artifacts when used?


Should CMS be completely avoided? Know it introduced artifacts in 2016 OLEDs. Have heard conflicting info about 2017s.


Yes it can still cause problems. It is OK to use the hue control in moderation. Use a smooth color gradient pattern to look for ridges or other signs of trouble.


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post #1178 of 3197 Old 12-03-2017, 11:28 AM
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Quote:
Originally Posted by jrref View Post
^^^
If you raise the contrast above 85 the set will start to clip white severely.
I have confirmed that raising contrast above 85 will start the clip the RGB values at the upper end of the 236-255 range.

Yet I read this:

"TVs use a video range from 16-235. It considers levels below 16 to be black, and information above 235 is white. A calibrated TV will never display anything below 16 as anything other than black. Most will also treat everything over 235 as white since it should not exist in video content."
(from https://referencehometheater.com/201...ll-vs-limited/)

So you're saying my TV should be configured to distinguish each individual 236-255 value?

What about 1-15 values? To do that I'd need to set the black level to "high", which looks incorrect for movies as there are no deep blacks anymore. Assuming I have 16 = deepest black, why would I distinguish 235-255, but not 1-16?

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post #1179 of 3197 Old 12-03-2017, 02:11 PM
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Tried out some first calibrations on my B7 with HCFR and AVSHD709 patterns, to adjust greyscale and colours. I only touched 2-points WB+CMS and been following that Curt Palmes HCFR guide.
My first question if when to use 20-point WB and what additional benefints it gives me? I can make adjustments more granular?

Another thing thats been bothering me is black crush in near black content, I recently found that other thread where this have been discussed a lot.
One suggestion there is to raise luminance of +5 IRE and when testing with some content where I've experienced BC, this really works and gives more details I want for my personal preferences- instead of raising brightness and (and raising blacks).
What do I have to consider in general (when calibrating) if I raise luminance +5 IRE? Or can I just simply do this?
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post #1180 of 3197 Old 12-03-2017, 02:58 PM
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^^^
If you do the 20 pt WB, your black crush will go away, pretty much, without all the magic lol

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post #1181 of 3197 Old 12-03-2017, 06:42 PM
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Finally got around to measuring the transfer functions on my LG in HDR mode - results attached for 1000 nit master and 4000 nit master patterns. In each graph the three plots are dynamic HDR off, dynamic HDR low, and what BT.2390 tone mapping standard would recommend. The display does essentially no additional tone mapping with a 1000 nit master but quite a bit with a 4000 nit master, moreso than BT.2390 would recommend. Both cases follow the PQ curve quite well up to diffuse white (shown in the 3rd graph) when HDR dynamic contrast is off. Max output on a 10% pattern was 640 nits (warm 2) and 720 nits (cool). Note also that with a 4000 nit master the diffuse white point (typically near 100 nits/50% stimulus) is considerably lowered to 69 nits.
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post #1182 of 3197 Old 12-03-2017, 07:33 PM - Thread Starter
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Quote:
Originally Posted by zoyd View Post
Finally got around to measuring the transfer functions on my LG in HDR mode - results attached for 1000 nit master and 4000 nit master patterns. In each graph the three plots are dynamic HDR off, dynamic HDR low, and what BT.2390 tone mapping standard would recommend. The display does essentially no additional tone mapping with a 1000 nit master but quite a bit with a 4000 nit master, moreso than BT.2390 would recommend. Both cases follow the PQ curve quite well up to diffuse white (shown in the 3rd graph) when HDR dynamic contrast is off. Max output on a 10% pattern was 640 nits (warm 2) and 720 nits (cool). Note also that with a 4000 nit master the diffuse white point (typically near 100 nits/50% stimulus) is considerably lowered to 69 nits.
The third slide shows that dynamic contrast low with a 4000 nit master is not tracking the PQ EOTF well at all.

I don't understand why LG is doing this. The mastering level is not a good indicator of content.
Media could be the same but have different metadata and the LG would display it differently.

Sony correctly ignores the metadata max nits when using dynamic tone mapping.

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post #1183 of 3197 Old 12-03-2017, 07:58 PM
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Quote:
Originally Posted by RichB View Post
The third slide shows that dynamic contrast low with a 4000 nit master is not tracking the PQ EOTF well at all.

I don't understand why LG is doing this. The mastering level is not a good indicator of content.
Media could be the same but have different metadata and the LG would display it differently.

Sony correctly ignores the metadata max nits when using dynamic tone mapping.

- Rich
Sorry, the 3rd graph was mislabeled (fixed now) which may have caused confusion. It shows that with dynamic HDR off the display ignores the metadata as it should and follows the PQ curve well beyond the diffuse white point which is critical for accurate color reproduction. But you are correct, at the low dynamic contrast, 4000 nit material is tone mapped incorrectly, at lease as far as BT.2390 is concerned. And starts to deviate from PQ well below the diffuse white point, which in my opinion is not desired.
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post #1184 of 3197 Old 12-03-2017, 08:15 PM
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Here is what they are actually doing with their tone mapping - they move the diffuse white point lower for mastering maxL > 1000 nits and then apply the BT.2390 function. I've not heard of a good rationale for that unless the intent is to reduce eyestrain.
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post #1185 of 3197 Old 12-03-2017, 10:51 PM
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Chad, thank you.


Im using sonoftumbles settings just for sdr and on my set and referencing basic slides / gradients / real world viewing look great. I have very good eyesight...better than 20/20 and turning off his cms adjustments appears to have removed some visible artifacts Even crazier...I swear motion is slightly cleaner now, is that even possible? Trumotion and processing stuff is off. Thanks to you both.
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post #1186 of 3197 Old 12-04-2017, 06:11 AM
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I am having problems getting my B7 to be as close as possible to my VT50 plasma, everything is summarized to the gamma, with 2.2 the oled sometimes looks quite bright, even with low oled light, then there is the gamma bt1886 that gives a lot contrast and but I think that details are lost in the shadows.

my room is normally dark but in the day it can filter a little sun light, what do you recommend, keep 2.2 or configure the bt1886 with oled light?
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post #1187 of 3197 Old 12-04-2017, 06:46 AM
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Quote:
Originally Posted by zoyd View Post
Finally got around to measuring the transfer functions on my LG in HDR mode - results attached for 1000 nit master and 4000 nit master patterns. In each graph the three plots are dynamic HDR off, dynamic HDR low, and what BT.2390 tone mapping standard would recommend. The display does essentially no additional tone mapping with a 1000 nit master but quite a bit with a 4000 nit master, moreso than BT.2390 would recommend. Both cases follow the PQ curve quite well up to diffuse white (shown in the 3rd graph) when HDR dynamic contrast is off. Max output on a 10% pattern was 640 nits (warm 2) and 720 nits (cool). Note also that with a 4000 nit master the diffuse white point (typically near 100 nits/50% stimulus) is considerably lowered to 69 nits.
Thanks for the update but this is really old news. There was some rationale from LG. Discussion is towards the beginning of this and the A1E calibration threads. Vincent Teoh also has a video on this topic. The overall problem is that there are no standards for tone mapping and manufacturers do what they think is best and can change it any time, and Sony has since the beginning of the year.

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post #1188 of 3197 Old 12-04-2017, 07:38 AM
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Quote:
Originally Posted by onaga View Post
I am having problems getting my B7 to be as close as possible to my VT50 plasma, everything is summarized to the gamma, with 2.2 the oled sometimes looks quite bright, even with low oled light, then there is the gamma bt1886 that gives a lot contrast and but I think that details are lost in the shadows.

my room is normally dark but in the day it can filter a little sun light, what do you recommend, keep 2.2 or configure the bt1886 with oled light?
Because of the out of the box near black losing some detail at 2.4 these TV's needed Gamma 2.3 as a preset
Without a meter and fixing 20 point, you can help open up 2.4 blacks artificially by raising 5IRE 5 or 6 notches.

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Last edited by PeteNeat; 12-04-2017 at 07:56 AM.
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post #1189 of 3197 Old 12-04-2017, 07:39 AM
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Originally Posted by jrref View Post
The overall problem is that there are no standards for tone mapping and manufacturers do what they think is best and can change it any time, and Sony has since the beginning of the year.
The standard for tone mapping can be found here beginning at section 5.4.1 I don't know what Sony is doing but the B7 follows the recommendation with the exception of moving the diffuse white point for material mastered at higher than 1000 nits.
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post #1190 of 3197 Old 12-04-2017, 08:26 AM
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Originally Posted by PeteNeat View Post
Because of the out of the box near black losing some detail at 2.4 these TV's needed Gamma 2.3 as a preset
Without a meter and fixing 20 point, you can help open up 2.4 blacks artificially by raising 5IRE 5 or 6 notches.
This is also another interesting and much discussed topic. My opinion, is that LG is still slightly crushing blacks intentionally, even with the new firmware to limit the amount of near black noise that they still haven't been able to overcome. Why do I say this? Because every set I've calibrated, always has the gamma off in the lower ire's causing this. You would think that some sets would have correct lower ire gamma if that was the goal. Now LG has improved this issue a great deal and personally, I think the set looks pretty good, especially in Technicolor PM with the OLED light adjusted to your viewing environment because I tend to like a brighter PM with 1886 vs 2.2 gamma. We will have to see what they do for next years sets which we will get a glimpse of shortly.

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post #1191 of 3197 Old 12-04-2017, 08:47 AM
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^ Thanks for the info. You mention preferring Technicolor preset. Can you elaborate as to using this opposed to ISF Dark or Light?
I was under the impression all three were the same as far as calibration settings and readings were concerned.

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So based on the discussion regarding HDR, it sounds like Dynamic Contrast is best left off if accuracy is desired? DC doesn't appear to do much for 1000 nit material, and for 4000 nit material it doesn't follow the BT.2390 curve well at all. What purpose does it serve for correctly mastered content?
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Quote:
Originally Posted by jrref View Post
This is also another interesting and much discussed topic. My opinion, is that LG is still slightly crushing blacks intentionally, even with the new firmware to limit the amount of near black noise that they still haven't been able to overcome. Why do I say this? Because every set I've calibrated, always has the gamma off in the lower ire's causing this. You would think that some sets would have correct lower ire gamma if that was the goal. Now LG has improved this issue a great deal and personally, I think the set looks pretty good, especially in Technicolor PM with the OLED light adjusted to your viewing environment because I tend to like a brighter PM with 1886 vs 2.2 gamma. We will have to see what they do for next years sets which we will get a glimpse of shortly.
for those that will never have a meter or calibrate(third world yeah!!!) do you recommend keep gamma bt1886 for most situations?
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post #1194 of 3197 Old 12-04-2017, 11:06 AM
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Originally Posted by onaga View Post
for those that will never have a meter or calibrate(third world yeah!!!) do you recommend keep gamma bt1886 for most situations?
The problem with the bt.1886 setting on my display (and from reading others this appears to be generally true) is that it's too dark and you will loose detail especially in the shadows. It should measure a 2.4 but measures closer to a 2.5 power law. When properly calibrated it looks great in a dim surround. But if you can't calibrate it I would use 2.2
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Originally Posted by PeteNeat View Post
^ Thanks for the info. You mention preferring Technicolor preset. Can you elaborate as to using this opposed to ISF Dark or Light?
I was under the impression all three were the same as far as calibration settings and readings were concerned.
They are just pre-sets but Technicolor is a bright preset like ISF bright only with the gamma set to 1886.

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post #1196 of 3197 Old 12-04-2017, 12:22 PM
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Quote:
Originally Posted by cacophony777 View Post
I have confirmed that raising contrast above 85 will start the clip the RGB values at the upper end of the 236-255 range.

Yet I read this:

"TVs use a video range from 16-235. It considers levels below 16 to be black, and information above 235 is white. A calibrated TV will never display anything below 16 as anything other than black. Most will also treat everything over 235 as white since it should not exist in video content."
(from https://referencehometheater.com/201...ll-vs-limited/)

So you're saying my TV should be configured to distinguish each individual 236-255 value?

What about 1-15 values? To do that I'd need to set the black level to "high", which looks incorrect for movies as there are no deep blacks anymore. Assuming I have 16 = deepest black, why would I distinguish 235-255, but not 1-16?
Hi, if you increase your brightness slider to see levels below reference black (16), your display will not display black anymore, because you will have just increased your black level. (black will become gray).

For above 100% Reference White (235) levels, I prefer to leave headroom for safety reasons, so to not clip for everything above 235, usually users are checking only Contrast pattern with classic Gray flashing bars, it's better to check WRGBCMY bars flashing and additionally Color Luminance Clipping patterns with RGBCMY Bars. There a lot of times one pattern to be ok and checking the other 2 to see clipping sooner. Having headroom improves all the levels near 100% of the signal also.

Focusing to consumer Blu-Ray Mastering; post production studios are working the movies with peak output 100-120nits 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) until it re-converted at the final stage to RGB to go to the panel.

So after all these conversion, add the rounding errors, add player inaccuracies to their output, add player/display to conversions..... maybe the 235 will go to 236 or 237 or 238 etc....or more..

Now all the displays in the market have a lot of higher peak output (300-400nits calibrated easily) from the peak output movies (SDR 100-120nits) has been mastered, you are not reducing the display contrast or peak output when you sacrifice some contrast controls values reduction to avoid clipping (for safety reasons) for above reference white or color luminance...like it was happening before years when we had plasma's (where some of them had lower peak output from 100-120 nits)...when we were clipping to able to get higher calibrated peak output (so higher contrast ratio).

Look this example, I got the change to measure the output of Pioneer BDP-LX91 Blu-Ray Player (2009 model with $2.500 price player) for digital errors.

I used my Blu-Ray (1080p) calibration disk loaded to Pioneer's drive and the CalMAN's ColorChecker Classic (+Primary/Secondary Colors with 100% Saturation / 100% Stimulus Level) Chapter with DVDO AVLab TPG Color Checker function (where it displays the digital level of the selected pixel on screen) to measure it's pattern output for digital errors when you playback a blu-ray.

Here is an example about what errors can introduced during a colorspace conversion (from YCbCr 4:2:0 to RGB-Video):

Since content is 4:2:0, the conversion from 4:2:0 to 4:4:4 requires vertical upsampling and horizontal upsampling. This is usually performed in two steps, from 4:2:0 to 4:2:2 (vertical upsampling) and then 4:2:2 to 4:4:4 (horizontal upsampling) and then to RGB-Video.



As you can see to the 100% Blue, from 235 it became 239, and it was a reference player (inside to the TV also, errors can be added), there a lot of that kind of colorspace conversions or internal processing that can add errors to the signal and alter the levels, this is why it's important to calibrate from your player, to be able to measure and fix any errors introduced during colorspace conversions, to have the whole video chain calibrated.

Here are the instructions; as reference; by THX Level II:



and by ISF Level II:



...they both agree to leave headroom and not clip to 235.

Setting Contrast slider affects Color Luminance also, so a lot of times a few clicks or Contrast reduction is reducing the clip at Color Clipping Pattern also.

You are not reducing contrast when you will have Contrast and Color Clipping pattern flashing bars above 235 until 253 flashing with modern displays, unless you have a Panasonic Plasma which can do 80 nits max for example, at this case you sacrifice and clip to see more calibrated nits output. No with projector which can output 100-200nits and displays which can do in SDR 300-500nits, you are not loosing contrast when you calibrate for 100-120 nits target for displays or 48nits for projectors, you just are safer from unexpected clipping that can appear to specific pixels it's difficult to measure; errors will be introduced from video signal multiple processing/conversions.

Because the conversions of RGB -> YCbCr -> RGB is the only reason which it's required to not clipping to 235; because the conversions produce out of TV legal range values.

Stacey Spears has posted a lot of picture examples with still images where the YCbCr conversion to RGB is producing levels beyond 235, up to 254:

"High Definition Benchmark" BD Edition by Stacey Spears and Don Munsil
"High Definition Benchmark" BD Edition by Stacey Spears and Don Munsil

Stacey has posted also here:

''Neither PC or VIDEO color conversion will restrict YCbCr 16-235 into RGB 16-235.

Before anyone says something about Car's being an animation, I can post a frame from any HD title and show the same thing. An example I gave in the other thread was: Y 140, Cb 161 and Cb 202 would convert to R 254, G 100, B 200 using the BT.709 color matrix. If you used PC levels, which expand, you would get R 277, G 98 and B 214. Since we don't go above 255, R would get clipped to 255.''


The fact is that ISF and THX both agree to no not clip and leave headroom.

Even Michael Chen has posted about this here:

''In the ISF and THX classes, people are taught to keep all detail to 254 ...

Not sure where people are taught to clip above 235 ... certainly not in the professional end of things.

Michael Chen @ The Laser Video Experience
ISF/THX/TLV Video Instructor
The Video Calibration Education Hub

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post #1197 of 3197 Old 12-04-2017, 01:05 PM
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Originally Posted by jrref View Post
They are just pre-sets but Technicolor is a bright preset like ISF bright only with the gamma set to 1886.
So if I changed Technicolor's gamma up from 1886 to 2.2, it's basically the same as ISF Bright? I should knock it back to 1886 so that there's an actual difference between the two?
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post #1198 of 3197 Old 12-04-2017, 01:12 PM
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^ As John has confirmed, I use all three as random place holders for varying test and production configs. ISF Bright could be a temporary dark config etc etc.
When comparing two different but 'similar' setups I try to keep one by the side of the other so that you can flick between them to compare.

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post #1199 of 3197 Old 12-04-2017, 03:06 PM
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Originally Posted by ThierryXN View Post
So if I changed Technicolor's gamma up from 1886 to 2.2, it's basically the same as ISF Bright? I should knock it back to 1886 so that there's an actual difference between the two?
Yes and you would have to take the color gamut out of Wide on ISF Bright if you were to do the comparison.

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post #1200 of 3197 Old 12-04-2017, 03:41 PM
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So if I changed Technicolor's gamma up from 1886 to 2.2, it's basically the same as ISF Bright? I should knock it back to 1886 so that there's an actual difference between the two?
Quote:
Originally Posted by jrref View Post
Yes and you would have to take the color gamut out of Wide on ISF Bright if you were to do the comparison.
Haha, I think I changed ISF Bright's color gamut to Auto as well. So I basically made the two modes the same thing under different names.
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