Fine tuning the White Balance on my new LG 50PS8000

[Anonymous]

aliEnRIK:
David Fuller:What do you have your contrast set at? Take it down to 60/70 and try again. Seems to be a bug in some sets where the 60ire and above sometimes stick and don't move when you adjust them, with contrast set too high.

An interesting answer, but surely it should be fine of contrast is properly calibrated? or is THAT too high? (if so that is one MAJOR flaw of the tvs design)

No, it's a known software bug in some of the PS series sets, lowering the contrast is known to show it up, i.e. if he lowers the contrast and then moves the controls for the greyscale and they jump its a software glitch. Only a small number seem to have this fault, one review mentioned it a while back.

BTW, setting contrast too high can interfere with greyscale results as colour energy can run out if asked to push too hard, but it is normally red which dies away first, which in this case (red to high) obviously points to the software issue and not overdriving the contrast control.

 

[Anonymous]

OK! Sounds like a plan! And it also seems to make sense because I couldn't really get those higher greyscale readings to change at all.

I've had the Contrast at about 90 when callibrating the greyscale, as that's the first adjustment the callibration guide tells you to do. 90-91 got me my Y luminescence of 35. So what you seem to be suggesting is to drop the Contrast down to 60, try the RGB controls on the 60-70IRE windows and see if I get a satisfactory response. If I do then it should be OK to crank the contrast back up again once the greyscale has been set?

If that doesn't work then I'll be asking Currys to replace the set.

Can you point me in the direction of the review(s) that mention the fault?

 

[Anonymous]

Mez:
OK! Sounds like a plan! And it also seems to make sense because I couldn't really get those higher greyscale readings to change at all.

I've had the Contrast at about 90 when callibrating the greyscale, as that's the first adjustment the callibration guide tells you to do. 90-91 got me my Y luminescence of 35. So what you seem to be suggesting is to drop the Contrast down to 60, try the RGB controls on the 60-70IRE windows and see if I get a satisfactory response. If I do then it should be OK to crank the contrast back up again once the greyscale has been set?

If that doesn't work then I'll be asking Currys to replace the set.

Can you point me in the direction of the review(s) that mention the fault?

Forget about your luminance figures. I will explain later on that. Drop the contrast control down and see what happens with the RGB controls. You should be able to get them right from that point. Once you have them correct, do a constant measure at 100% and slowly raise the contrast control. This should give you the desired full dynamic range give or take a few notches up or down (assuming you have set black levels (brightness) correctly) you are looking for a setting where the mix at that level remains constant, if it moves you have gone too far with the contrast control. Remember that you ideally want one expert setting saved as daytime viewing, with higher contrast and one for night viewing (if your viewing room lighting changes during the day). Type 8741 to save your calibrations when the expert control selection is highlighted.

In terms of luminance levels for contrast, don't look for consitancy here, it will vary depending on room, lighting and sources. You want to look for around the 30ftl for night viewing and around 50ftl max for daytime.

I can't point you to the 50PS7000 or 50PS8000 reviews as they are on another forum site that WHF don't allow linking too. Google it; is the best option.

EDIT: If the controls do not move when you lower the contrast then you have a fault and should report this to your retailer for replacement.

 

[Anonymous]

Excellent! Being a shameless (and therefore very annoying) perfectionist I'm going to try this tomorrow. My Mrs will love you ...

I've found a review of a full callibration at another site and so also now have some figures to aim for. This review doesn't mention the high contrast v D65 issue but does show that it is possible to get dE under 1 across the range. It also mentions restrictions in the colour gamut which also explains why I can't hit the true Rec.709 points, but again the review gives me some xy targets.

Thanks for the ISF codes. I also hadn't considered using the two Expert setting memories for daytime and night-time viewing. Hmm. How much more strain can my marriage take ...

Thanks again David

 

[Anonymous]

You're welcome...

Also, remember to chose the correct dE error system. It should be set to 1994 in your software and not 1976. I forgot to mention the blue target (colour point) being off slightly, it's no biggie in this case as you will no see any error on screen, the LG looks nice and accurate when fully ISF calibrated. Have fun!

 

[Anonymous]

Sorry for the delay in replying.

You were right! It was the contrast! I turned the contrast down to 60 and recallibrated the greyscale from 5-100 IRE. After a couple od spins at it, I've managed to get everything except 10IRE below a dE of 3. (It's Mr 10IRE's come-uppance this Saturday).

Increasing the contrast did start to introduce some kinks in the grey-scale, but I've managed to get it up to 68 (which gives me the same Y readings from the expert callibration report I referred to before) with the dE's still below 5.

My main problem now is getting the colours close to 709 standards. The secondaries are quite close, but the primaries are all out, even at max/min colour and tint settings in the CMS.

But once I've tamed the 10IRE I'm sure I won't be able to tell the difference.

 

[D.J.KRIME]

With you contrast as low as 60 surely on the 100IRE your Y reading must have been way bolow the target of 30-40ftl?

 

[Anonymous]

It was. It was about 26-27 at 60. But at 68 it's about 30-31, so I'm happy with that.

The word compromise usually doesn't feature in my vocabulary, but I've learned its meaning over the last few weeks!

 

[D.J.KRIME]

Mez:

The word compromise usually doesn't feature in my vocabulary, but I've learned its meaning over the last few weeks!

I think this is a word most of us who chose to get "geeky" and start to use sensors etc to calibrate our TV's get quite acustomed with LOL.

If you have goten near to 3DE either side of the "perfect grey scale you have done fantastically well. My set unlike yours does not have indivual white ballance controls for each point along the IRE scale but one that affects the entire range. The best I have managed is (forgeting 20IRE and below) within 3DE @30IRE the drifts up to about 6-8DE out at certain points then back to about 3DE @80IRE and within 5/6DE @90 and 100IRE with a FTL of 31 with contrast @90.

I can't get it any closer in the higher end of the scale as I have my Blue gain control set to 0 yet blue still reads on average about 104 where red and green are 99-100 at most points from 50IRE upwards.

I gave up trying to get any where near to the perfect grey scale under 20IRE a long time ago!!!!

 

[Anonymous]

Well, you know, the 10IRE is over 10 dE - probably about 15, but I'm amazed how noticable that is, even right down there at 10IRE. Of course, my 5 and 15 might also be out, but the CFHR software doesn't test the 5 and 15 levels.

We watched "A Haunting In Connecticut" on blu-ray last weekend on my new settings and, being quite a dark film (as you'd expect!) there was a noticeable glare on skintones and browns at lower light levels. I actually switched back to the set's THX-certified settings until I fix the 10IRE problem.

Mind you, considering how much of the film I saw behind the cushion, I needn't have bothered ...

 

[D.J.KRIME]

I think the issues I have below 20IRE are more down to the Spyder's ability to get acurate readings at such low light levels as IMHO I can't see how the rest of my greyscale could be as close as it is to the "holy grail" 0 line and below out by 15-20DE at 0 and 10IRE (20 IRE is about 10DE out)

For what it's worth My Samsung has no secondary controls (not that I could find anyway) to adjust the Primary or Secondary colours but on the graphs My Samsung actually scored incredibly well with both primary and secondary colouer which was a big thumbs up

 

[Anonymous]

Fair play.

Yeah I don't 100% trust my Spyder down below 20IRE but the effect on actual HD content seems to bear out that the greyscale is out at those lower levels.

I'm a bit miffed about my colour gamut on the LG if I'm honest. The numbers might tell me that my Red Colour needs to be -50 and my Red Tint +50 to get closest to the standard, but I'm wary of having to move the setting so far away from the centre point. But, as with the 5-100 IRE adjustable RGB, I'm finding that there isn't much previous experience of the PS8000 to work from so I'm making it up as I go along, which is why you guys have been so brilliant on here.

 

[D.J.KRIME]

My readings below 20IRE would sugest that my red is way to high yet on veiwing many movies there are not traces of over saturation of red in the darker areas of the picture so I have left well alone. I do plan to have another "play" when I have some spare time and try from scratch using a slightly lower contrast setting which may result in not quite hitting 30ftl but may just end up giving a slightly straighter line on my greyscale readings. Either way I allways not my current settings so I can revert to them if all goes t##s up

Like you I was/am in the same boat as where we both have TV's that are not as popular as others on these forums, so inturn you are left a little to your own devices when trying to acheive certain things as there are few members that have experienced exactly what you are (I am yet to come accross anyone on here with the same model Samsung as me)

Like I know how to get into the service menu of my Samsung but I have no clue what most of the settings in there do, so have left well alone even tho there may well be something there to help better my greyscale or primarys and secondarys, but without expert advice in there I will stick to the standard user menu tools where if needed I can always hit RESET.

 

[Anonymous]

Mez:
Fair play.

Yeah I don't 100% trust my Spyder down below 20IRE but the effect on actual HD content seems to bear out that the greyscale is out at those lower levels.

I'm a bit miffed about my colour gamut on the LG if I'm honest. The numbers might tell me that my Red Colour needs to be -50 and my Red Tint +50 to get closest to the standard, but I'm wary of having to move the setting so far away from the centre point. But, as with the 5-100 IRE adjustable RGB, I'm finding that there isn't much previous experience of the PS8000 to work from so I'm making it up as I go along, which is why you guys have been so brilliant on here.

Forget about getting anything under 30ire correct with a spyder, or for that matter any of the cost effective meters - they just cannot manage an accurate reading. You would need to spend quite a bit on a meter that is accurate with low light. However, it looks like you have managed to get very good results with the greyscale. If you have obvious errors that you can see under 20ire, then try and balance the correct bottom end with getting rid of the errors. After all we are talking about consumer displays where even the most expensive can struggle to get perfect - hell even pro broadcast monitors are hard work!

Also, although there are recommendations of what ftl you should be aiming at, as you have learnt yourself it is more important to set the overall image brightness to your environment as well as aiming to try and keep the greyscale correct.

Colour management calibration is an altogether different beast to get correct. IIRC the LG saturation controls also affect luminance (which HCFR doesn't measure and is a real downside to the free software) and hue does what you would expect. I could type for hours on what you should do, but instead I recommend you read Curt palmes website on this subject as well as the AVS american forum calibration area. You will get everything you need from there to get your head around the concept. I have also heard that there will be some enthusiasts training taking place soon, which while a paid course, teaches people everything they need to know up to the same level as the pros, info here: www.aventhusiast.co.uk

Glad we managed to help you with the greyscale, any other issues?

 

[Anonymous]

You know, the more I play around, the more I seem to understand about how all these settings affect each other. I had yet another go at the greyscale last night and have got everything to below 3 dE except IRE10 which is at 3.5. But here's the interesting bit. The 'problem' grey level is 15IRE. Now, the ColorHCFR sotware doesn't take readings at 15IRE when testing your greyscale. But I can see that there is too much red in it. But when I reduce the red at 15IRE I've found that it also affects the 10IRE picture by washing the red out of there leaving it almost green!

So why is this happening? I have only come up with two theories:

1. What purport to be discrete settings for each of the 20-points on the IRE scale, actually define three (R,G & B) binomial curves across the greyscale. Therefore, signficantly adjusting one part of that curve actually pulls the neighbouring IRE points out of joint.

2. The LG is allowing the adjacent IRE settings to 'bleed'. After all, how do I know that what my set calls 15IRE (at which I make the adjustments) is exactly the same as the 15IRE pattern on my HD Essentials test pattern? What if my adjustments are actually to something nearer 12-13IRE which might be why it's affecting the 10IRE image?

This is intruiging me, as a self-confessed perfectionist. At the moment I am having to compromise on my 10IRE in order to keep the 15IRE in the ball-park (otherwise I get the god-awful 'glare' at lower lighting levels). Any ideas?

As for the colour gamut, I've been using Curt Palme's callibration guide all the way through and have decided that where I got to last night is the closest I'm going to get. Most dE's are over 10 (and Red is over 20) but the other forum narrative I read found the same results. It's not really noticeable to be honest.

The only other question I have is on a couple of advanced picture settings that I don't seem to be able to access. One is the colour field setting (permanently set to HD but of course that's fine) but the other is a setting called something like xvYCC, which is currently set to Auto. This box is greyed out on every picture setting, including the two Expert settings. Any clues?

 

[Anonymous]

Mez:
You know, the more I play around, the more I seem to understand about how all these settings affect each other. I had yet another go at the greyscale last night and have got everything to below 3 dE except IRE10 which is at 3.5. But here's the interesting bit. The 'problem' grey level is 15IRE. Now, the ColorHCFR sotware doesn't take readings at 15IRE when testing your greyscale. But I can see that there is too much red in it. But when I reduce the red at 15IRE I've found that it also affects the 10IRE picture by washing the red out of there leaving it almost green!

Yes everything effects each other. Its a balancing act, even more so for colour points.

So why is this happening? I have only come up with two theories:

1. What purport to be discrete settings for each of the 20-points on the IRE scale, actually define three (R,G & B) binomial curves across the greyscale. Therefore, signficantly adjusting one part of that curve actually pulls the neighbouring IRE points out of joint.

2. The LG is allowing the adjacent IRE settings to 'bleed'. After all, how do I know that what my set calls 15IRE (at which I make the adjustments) is exactly the same as the 15IRE pattern on my HD Essentials test pattern? What if my adjustments are actually to something nearer 12-13IRE which might be why it's affecting the 10IRE image?

This is intruiging me, as a self-confessed perfectionist. At the moment I am having to compromise on my 10IRE in order to keep the 15IRE in the ball-park (otherwise I get the god-awful 'glare' at lower lighting levels). Any ideas?

You are expecting a consumer display and your probe to be accurate at extremely low light levels. Neither will be correct or accurate, its just the nature of the game. As long as your greyscale errors are not visible to your naked eye at these levels, then thats the best you are going to get with the equipment and panel you have.

As for the colour gamut, I've been using Curt Palme's callibration guide all the way through and have decided that where I got to last night is the closest I'm going to get. Most dE's are over 10 (and Red is over 20) but the other forum narrative I read found the same results. It's not really noticeable to be honest.

As noted above, it is a balancing act with a consumer display, some do it better than others. As long as you are as close as you can possibily get using the tools you have and there are no visible errors to the eye, thats the limit you have reached.

The only other question I have is on a couple of advanced picture settings that I don't seem to be able to access. One is the colour field setting (permanently set to HD but of course that's fine) but the other is a setting called something like xvYCC, which is currently set to Auto. This box is greyed out on every picture setting, including the two Expert settings. Any clues?

Ignore both. One is selecting the HD ITU-BT.709 colour space (HD) and the other is one of those manufacturer added options for camcorder footage shot with the wider xvColour space. That is not relevent to 8 bit video.

Hope that helps. Now sit back and enjoy your TV!

 

[Anonymous]

The force is strong with you David Fuller ...

This guy knows his onions ... !

 

[Anonymous]

How annoying. I spoke to LG yesterday ref. this issue with the 'bleeding' greyscale and x-ref my other topic re firmware updates for this set. They told me that:

a) they were unaware of any software issues concerning the greyscale callibration; and
b) there were no firmware updates planned unless serious flaws were discovered with the set and so the version supplied with my set in July was the most up-to-date.

Surely firmware updates aren't just for serious flaws? My other kit seems to be up for updates every month, on average!

Do you think I was being fobbed off? If the first 20-point greyscale callibration system on a UK consumer set can't get me an acceptable greyscale because of 'bleeding' (my word - not technical!) then surely they should be doing something about it?!