Official LG xxLK520 xxLK450 - Page 87

^ ^ ^ I guess.

The point of my initial post was to compare power law gamma (2.2) versus BT.1886 (using Expert 1/2 on the same input). I could then see which looks better overall and why. Of course, I just posted the baseline for now until I get my hands on CalMANv5.

I don't need to justify my "purchases of expensive modern electronic devices" by using it often. I only do that out of curiosity and to get better at calibrating in general. Some differences are significant, others aren't. My guess is that the new gamma standard will be the former.

I think by separating shadow details further apart from the elevated MLL, dark scenes might actually have better overall contrast and definitely detail near black. Also, gamma will be higher than the power law formula at the top end, so that aspect of the picture will have more depth, detail, and contrast.

At the very least, it could make a nice Day mode.

OTOH, if the goal is to emulate a typical CRT response, I think this approach is going to lead you in the opposite direction of where you wanted to go.

My now retired RPTV had an overall gamma of 2.4 ... the "dark end" was closer to 2.6, while the high end was closer to 2.2 (or even 2.0 between 90 and 100%)

One of my issues with calibration runs current -1 and -2 was that they looked too washed out. Those were the runs where 10% was brighter than the gamma=2.2 10% target ... The current run has a measured gamma of ~2.35 @ 10% with black level compensation and ~2.23 without compensation. It looks much better than run current -1 or -2.

Those inky CRT blacks usually involved some sacrifice in shadow detail. So in short, I think you're heading backwards.

But I've only been doing this since 1995 ... so what do I know.
Edited by HDTVChallenged - 6/10/12 at 10:01pm

A random thought:

I think part of the "problem" here is that easy to use packages like Calman and Chromapure have turned the "business" of calibration into something more like a video game where the goal is more about chasing numbers and making pretty graphs than making actual improvements in display quality. Which is fine if all you want to do is "play the game(s)." It's easy to get pulled into that trap and the next thing you know you've spent $1500 and invested countless hours calibrating a $525 TV. OTOH, Some of us would rather be watching actual content, like movies and TeeVee shows. YMMV.

I do spend far more time watching the TV than calibrating it. I have Netflix and GameFly subscriptions, so I'm always watching BD movies and playing PS3/X360 video games. Also, I do have other TVs and monitors at home, which I also calibrate. No need to bash on quality, up to date calibration software that isn't freeware and meters that aren't cheap. And I could care less how much the TVs costs in terms of whether it's worth calibrating fully or not.
Edited by PlasmaPZ80U - 6/11/12 at 8:08am

I'm not bashing anything ... I'm just saying it's easy to lose one's perspective. It's even easier with 'modern up to date' software.

Do we (as a community) post our calibration results for the benefit of others, or has the calibration section of AVS become more of a "high score" bulletin board? To me, over the ten years that I've been "active" here, things seem to be trending toward the latter. OTOH, it's possible that I'm just turning into a grouchy old codger.

Hey all, I finally purchased a 37LK450 with the coveted S-IPS panel. Unfortunately my tv has a buzzing noise coming from what I believe is the backlight behind the set. I can still hear it when I'm sitting in front of the tv (5-6 feet away) when the tv is on and all is quiet around me or no other sources are running (Dish box, PS3, etc). It goes away when the backlight is set to 99 or 100, but not entirely. I searched this site for the problem and came up with no real solutions.

It's pretty irritating, but I was wondering if the problem goes away in time? Or does my tv have something defective inside?

Hopefully there might be a solution to the problem. Because if not, then I could be returning the tv back to Staples. They only have a 14 day return policy BTW.

Got the remote and that what it was. I can label my inputs now

Ok, so I looked up the actual BT.1886 function definition and did some cypherin' with calculator, paper, pencil and HCFR (original recipe.)

Without posting the entire calibration file, lets take it as a given that my last calibration run had an average power-law gamma of 2.21, flat 20-100% with a "rise" to 2.35 @ 10% stimulus.

So using the Lb(=0.118N) and Lw(=101.260N) from that last run, I calculated the BT1886 function at eleven discreet points (0,10, ... 90,100%) Results follow along with the effective gamma calculated by the power-law function.

Lw = 101.260Nits
Lb = 0.118Nits

a = 87.300
b = 0.063757

y = 2.40

The BT1886 10% L is almost twice as bright as my current run, while the 30-100% L's, oddly enough, are pretty close to the current values.

I don't know what the ITU is thinking, because this is gamma "curve" is completely the opposite of every CRT I've ever measured ... Perhaps I've missed something? Either way, I don't think this would present a very good picture on my LK450 ... seems like it would be very "washed out."

YMMV.

Edit: Minor mistake, I forgot to switch the HCFR reference to display gamma with black level compensation, which the BT.1886 function incorporates ... albeit in a complex way. The corrected values w/ BLC should be a more valid comparison.
Edited by HDTVChallenged - 6/11/12 at 11:09pm

may I ask why you set gamma to 2.35 at 10% gray? Mine looks plenty dark at 2.20 without black level compensation enabled.

This is an inherent issues with these. I had 3 different 37lk450's and 2 42lk450's and 1 37cs520 (2012) and all of then made a buzzing noise from the backlight. I called LG and the guy told me it was something in my house. Funny thing is I have a 42lk520 in my LR and there is no noise. This was also a issuse with some of the ld model year. If the backlight was turned up to 100 the noise would go away. To me LG is using cheat lights and inverters. To me the IPS panel wasn't worth the noise. I hear buzzing lights all day long in my shop really don't want to hear that when tring to play xbox. And the fact IT WAS A BRAND NEW TV. I've only waited 10 years to get a HD tv. So either live with it or buy something else. I got a sammy and im extremely happy with it for gaming.

Bummer. Well, if after contacting LG about this issue doesn't fix the problem, then the TV will have to be returned unfortunately. And I can't live with a brand new TV making a buzzing noise like that. This is odd because I have a couple of other cheap, off-brand LCD TVs in the household that don't make that buzzing sound when simply turned on.

Because you mentioned the IPS panel wasn't worth the noise, will a 37LK450 equipped with a VA panel have the same buzzing noise from the backlight or not?

The 2.35 figure is with black level comp ... without the BLC it's 2.23. Given the previous run's "washout effect," I do remember intentionally trying to get the 10% as close to the LG's computation as possible. LG calculated 0.6N, I wound up at 0.589N ... slightly lower than it "should be" according to LG.

On the bright side, I guess the BT1886 function will make it much easier to hit D65 @ 10% stim. It's too bad that it's pretty much going to break everything that pre-dates BT1886. Without actually testing BT1886 on the LG, I also have to wonder if it's going to introduce banding on the LG's when/if we try to force it with the 10pt.

Also made a few adjustments related to black level comp in post #2618 above.

PS: Remember that this is my first non-CRT based display ... I have certain expectations wrt to black levels, and how things should look.
Edited by HDTVChallenged - 6/11/12 at 10:50pm

Not sure never had a LG with a va panel. If your going to get a va buy a sammy. Just make sure it has a sammy panel SPVA in it or a AUO AMVA. Dont get the CMO va it looks washed out to me. Imao the sammy has better processing than the lg and better blacks. This is my experience with both brands. I've also has a panasonic with an alpha ips but it was a little too dark for me and panasonic don't do the panel lottery. Search AVS for info on the sammy panel lottery there is a couple threads about them. I really don't feel like typing it all out on my phone. It is really disappointing that these make a buzzing noise even the stripped down CS (2012) models do the same crap.

This is a great TV for the money, but the IPS version's blacks are among the worst in the 2011 lineup of CCFL LCDs. I don't think brighter gamma at 10% would necessarily wash out the image, since darker gammas will only make dark details sink into the elevated bluish blacks and make you see more of that than actual shadow detail that is bright enough to stand apart from the glowing blacks. As long as the steps above aren't too bright, the overall image should still have plenty of contrast.

(Of course, it you wanted CRT-like blacks and the ability to use darker gammas without losing too much shadow detail, something like the Samsung LNxxD630 would be a better CCFL-LCD choice.)

Mine buzzes with certain types of patterns, like with on-screen menus or high contrast screens (black and white text) or grid-like patterns. In fact, there are specific patterns on the AVS disc that trigger the buzzing and the pitch and volume of the buzzing can vary from pattern to pattern.

On my LK450 I won't go over 40 on back-light because blacks get washed out and whites bloom, it doesn't matter what I have brightness and contrast set to. BTW: I've never heard a buzzing on my set no matter what the setting.

On my LD520 (which admittedly is a different animal) my backlight is set at 48 and it looks fine. I too have never heard any buzzing noise regardless of the setting or cal disk patterns used. There seems to be quite a few reports of buzzing with some of the 2011 models so I wonder what LG changed.

LOL ... The buying points for me were $$$, 10pt WB and smaller diagonal than old the RPTV (I was fed up with seeing artifacts/blocking on so-called HD material.) It was meant to be used for daytime, non-critical TV viewing, and limited gaming. Black level was *not* an important selection criteria. The set has met or exceeded all expectations. These criteria are also why I don't feel the need to put an i1Pro on the beast.

Bonus points for a working 24p -> 48Hz mode, ... and 1-to1 mapping at 1080p. The final choice was between this set and a 42/43" 720p Plasma ...

Unfortunately, experience (some of which was accidental ) would seem to suggest the opposite.

I've been rechecking my calculations, and I think at least half of the difference between the BT1886 and my current run is the use (or not) of BLC. It would be interesting to see what happens to the BT1886 numbers if one set Lb to zero, which would effectively take BLC out of the equation.

Hi, can someone please help me.

I bought 32LK450 and I just can't get 4:4:4 and pixel mapping 1:1.

I have GTX570, tried it with HDMI>HDMI, VGA>DVI and now HDMI>DVI ...When labeled as PC I get a bit sharper text, but it has some white glow/halo to it. It's terrible. When in Game mode, I get kinda blur around text.

I tried everything I could and no 1:1 ...

I don't know how to edit EDIT, it's confusing and some links are dead. Btw right now I'm on 6870 (borrowed) same problem, but a little less glow/halo around text. Does anyone have some edited EDID for 32LK450 ?

Some pics ..

This is on 6870 - PC mode (the best it can look)

http://i.imgur.com/BAnkf.jpg
http://i.imgur.com/p6Alm.jpg

This is on GTX570 (PC mode)

http://i.imgur.com/EYniE.jpg
http://i.imgur.com/IXyJK.jpg
http://i.imgur.com/UBa9b.jpg

P.S I have the one with S-IPS panel. March 2012, with "Y" in code. Also none of the windows effect such as clear type ect. fix the problem.
Edited by ocz4life - 6/12/12 at 10:47am

It's actually 96Hz.

Chad B confirmed this with his Jeti 1211.

The buzzing noise I was hearing was definitely coming from the backlight or inverter. It didn't matter what was on the screen or what input. If I would turn the backlight to 100 the noise would stop. Any other setting it would start and it would change pitch as I would change the setting. I Every single ld450 I tried had this I had two through amazon and the other three were from two differnet BB. Now my ld520 has no noise I bought from newegg. Even though when playing xbox I couldn't hear it due to my xbox. When watching tv I had to turn the volume up so I wouldn't hear it but changing channels it was plain as day. I just couldn't justify spending $500 on it and it makes a buzzing noise right from the word go. My concern was in a year or two is it going to die get worse get better or never change. Other than that I liked the PQ and features. But then I bought a sammy ln40d550 and it has better PQ and more features. No 10pt grey scale but you can still adjust enough. Ill never pay to have my tv professionally cal. There'd is no way im paying more for that than I did my tv. I adjust it to look good to me. To be honest I never heard of that until I join AVS.

On the 450's too ???

Anyway, my suspicions wrt to BLComp have proven to be true. It took me a couple of hours (most of which was looking up stuff I've forgotten) of C# coding to construct a quick and dirty BT1886 target calculator, and it turns out that with Lb (luminance of black) set to zero the BT1886 function actually calls for less luminance @ 10% than the power law @ gamma = 2.2. Much more CRT like. .... Plus now I have a new gadget to play with.

So I suppose all that's left now is to actually try it (BT1886) and see what, if anything, changes visually. The real issue here seems to be BLC vs. no BLC, rather than Power-Law vs. BT1886.

Hello everybody its the second time i am posting in this forum. I have read this thread because i am looking to buy a 37 inch panel.I hope you guys can help me out BTW I just care about PQ and dont care for smart features.
I currently own a LG 32LK450 with IPS and i am very happy with it , i especially like the colour fidelity and the excellent upscaling of SD material which is really good especially for On the air SD material which i use a lot. So my question is to get a 37LK450 with IPS or the 37LV5500 with IPS, i know the Lv is good in colour and probably better in motion but what about resolution scaling with SD material is it as good as the LK450? Would the LV be an upgrade or a downgrade PQ quality wise? BTW The LV versus the Lk would have a slight dimension advantage for the place i plan to put it in the bedroom.

They are both 2011 models but the LV5500 is a smart TV and has an LED backlight, I would get the LV5500.

Yes, after all I have the LK450 only, not the LK520.

Also, I'd like to take a look at that calculator (if you don't mind). I want to put in the data from my latest calibration, which uses 2.2 power law gamma without BLC.

It's not quite ready for primetime yet, but I'll see if it can be cleaned up a bit.

Anyway here are some important rules for deciphering technical standards:

1) Make sure your well rested.
2) Make sure you are sober.
3) And this is the important one: Make sure to read all the way to the end of the technical doc.

I think there's been a major misunderstanding about how the BT1886 ETOF is to be used (at least in my case.) Here it is ... buried in the "alternative method" section:

Lb and Lw are supposed to be set to the values from the CRT that you're trying to "match," not the Lb of the display that you're actually calibrating.

This produces numbers that actually make sense.

So after all the Sturm und Drang .... apparently I/we need to lower my/our 10% L(s) even further to "match" CRT performance. The world makes sense again ...
Edited by HDTVChallenged - 6/13/12 at 9:58am

.... Or not. Upon yet another reading, it appears that you can use it either way. Argh! Welcome to the latest episode of "When a standard goes bad."

So in other words, just twist the knobs until it "looks good."

I think I need a beverage ... maybe some ibuprofen ....

I think this explains why I'm waiting for the release version of CalMANv5 to come out so it can do all the math for me and display the results as cool looking charts/graphs.