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Guide: GREYSCALE CALIBRATION FOR DUMMIES - Page 5

post #121 of 258
Thread Starter 
Quote:
Originally Posted by rahull View Post

Not a expert but I think red runs out of gain first and others need to be adjusted to it.

Very good point! I forgot about that. That's probably the exact reason.

Quote:
Originally Posted by AVSman View Post

Thanks for putting this guide together, kal, I really appreciate it! I ordered an Eye-One Display LT from Amazon last night, and I'm looking forward to stepping through the guide. It's exactly what I've been looking for.

Thanks again!

Thanks! Hope you enjoy it and happy viewing!

Kal
post #122 of 258
This is an awesome tutorial. Very well written and easy to follow.

Thanks!
post #123 of 258
Thread Starter 
Thanks EHT. Glad you like it!

Kal
post #124 of 258
Thread Starter 
Quote:
Originally Posted by sperron View Post

You definitely might want to make an addendum about color run outs on digital displays.

I finally got around to adding some information to the guide about colour run-outs. Thanks to everyone for the tips/tricks and even the sample data! See section 6.11 (quoted below):

Quote:


STEP 6.12: A common problem with all displays if your contrast is set too high is 'running out' of a certain colour before the others as light output goes up beyond 80 IRE and approaches 100IRE. With digital displays the problem colour is typically red so we will use that as our example. Red light output will often hit a ceiling and stop increasing while contrast is turned up while green and blue output continue to increase. This causes a visible drop in red output in the 90/100 IRE points and looks something like this:







Why this happens (thanks for forum member Scott_R_K): In the early days of home theater many of the digital projector manufacturers were simply using slightly altered presentation projectors as home theater projectors. These projectors were intentionally built to produce higher blue and green outputs to produce a more vivid picture and higher light output as this is what was required for presentation situations: Light output was the primary concern at the expense of colour accuracy. The bulbs chosen for these projectors were also often very red deficient to begin with (something that a CC30R colour correction filter can help with - more on that later).

The only solution if you run out of red in at 90/100 IRE is to turn down your contrast. While displaying the 100 IRE pattern (see Part 4: Setting White Level) take continuous measurements and keep lowering the contrast until the x value (red) reads 0.313 or stops dropping. This will be the highest you can run your contrast and maintain a correct amount of red output in relation to green and blue.

If you have to reduce the contrast such that you're not longer within the target ftL light range for your type of display, you have a decision to make: Do you keep higher light output at the expense of having an incorrect upper IRE range? Or do you fix the upper IRE range at the expense of contrast ratio and light output? As is always the case, calibration requires deciding which trade offs to make to get the best picture for your particular set up. Try both and make the call.

While this sort of problem can also occur with green or blue, it's far less likely to happen on digital displays. Regardless, if you find one of the colours dropping off significantly above 80 IRE, try reducing your contrast to see if the problem resolves itself.

Kal
post #125 of 258
Has anyone had any trouble because of an anti-glare screen? I have a Mits. RPTV (65813) that I directly attached the Eye-One probe to the anti-glare screen. Well, the HCFR software is way off on color and tint. I ended up adjusting by eye with AVIA. HCFR showed me being totally off even though I know I was pretty darn close.

When I tried adjusting the primaries with my Lumagen HDP, I was unable to get the x/y's correct no matter what I tried. Again, I used AVIA for blue, red, and green saturation and hue, and just eyed-it. It came out pretty close, but HCFR said that it was way off.

Maybe I should try putting the probe on a tripod? It doesn't make sense to me to take the anti-glare screen off, do the measurements, then put the anti-glare screen back on. This would affect the picture. Correct?
post #126 of 258
Quote:
Originally Posted by joikd View Post

Has anyone had any trouble because of an anti-glare screen? I have a Mits. RPTV (65813) that I directly attached the Eye-One probe to the anti-glare screen. Well, the HCFR software is way off on color and tint. I ended up adjusting by eye with AVIA. HCFR showed me being totally off even though I know I was pretty darn close.

When I tried adjusting the primaries with my Lumagen HDP, I was unable to get the x/y's correct no matter what I tried. Again, I used AVIA for blue, red, and green saturation and hue, and just eyed-it. It came out pretty close, but HCFR said that it was way off.

Maybe I should try putting the probe on a tripod? It doesn't make sense to me to take the anti-glare screen off, do the measurements, then put the anti-glare screen back on. This would affect the picture. Correct?

And I thought I just finished calibrating my TV. Do you mean I have to re-do my calibration.

I also have my anti-glare screen on my Mit WS-A65 (Equivalent to WS-65311). I did not check the color decoder from AVIA to verify that. I can try tonight or tomorrow and see how much off I could be and get back to you.

If you do end up using a tripod, see post #16

http://www.avsforum.com/avs-vb/showthread.php?t=1039875
post #127 of 258
Quote:
Originally Posted by joikd View Post

Has anyone had any trouble because of an anti-glare screen? I have a Mits. RPTV (65813) that I directly attached the Eye-One probe to the anti-glare screen. Well, the HCFR software is way off on color and tint. I ended up adjusting by eye with AVIA. HCFR showed me being totally off even though I know I was pretty darn close.

When I tried adjusting the primaries with my Lumagen HDP, I was unable to get the x/y's correct no matter what I tried. Again, I used AVIA for blue, red, and green saturation and hue, and just eyed-it. It came out pretty close, but HCFR said that it was way off.

Maybe I should try putting the probe on a tripod? It doesn't make sense to me to take the anti-glare screen off, do the measurements, then put the anti-glare screen back on. This would affect the picture. Correct?

The anti glare screen actually adds Glare, take it off and leave it off. Calibrate it wioth out the screen and be prepared to see what you have been missing the enitre time with it on. Craig Rounds a pro Calibrator who specializes in Mitsus always takes them off and leaves them off. The screen is tinted also which alters the colors. I have the same TV and It is absolutly not going to get that screen back on again. One thing though, if you have kids with sticky fingers or that might scratch the screen then you may have to leave it on and find another way to calibrate it, maybe the tripod method.

Athanasios
post #128 of 258
I took the screen off. While the picture looks better, HCFR still says I'm off by around the same amount as with the screen on.

So, I'm either doing something wrong with the software? I've gone through the steps a dozen times, so I don't know what I could be screwing up there. Maybe wrong dll version--I have the 3.4xxxxx?

Or, the probe is no good.

Or, something else.

Any ideas?
post #129 of 258
Thread Starter 
FAQ: Which Meter is Right for Me?

Colorimeters, Spectroradiometers/Spectrophotometers? What's the difference and why do I care?

Figuring out which meter to use for calibration is often the hardest part of calibration, so I've put together a FAQ: Which Meter is Right for Me? It covers everyone from budget Spyder2 and Eye-One Display 2 / LT meters up to the the higher end professional grade Chroma 5, Eye-One PRO, and Hubble (Sencore OTC1000) meters.

The worse thing you can do is buy either a meter that is severly overpriced or underperforming for your specific needs. Give it a read and figure out which meter is right for you.

Hope it helps!

Kal
post #130 of 258
Your selection is obviously biased for DIYers, and for that market, reasonable. It implies, however, that there isn't much else out there. You might want to at least mention the Sencore, Progressive, and Minolta products, as well as a few others, even if they are priced out of the range of most non-professionals.
post #131 of 258
I am newbie for calibration. I am reading the guide for Dummies. My TV (LC46D82U) does not have any option for RGB levels to change.

Can you help? I have the normal adjustments backlight, contrast, brightness, color, tint, & sharpness?

Which one is the adjustment for RGB levels?

Thanks,

Manny
post #132 of 258
Greetings

None ... the controls are in the service menu. Gamma 1/2/3/4/5/6 which might work right or not.

regards
post #133 of 258
Quote:
Originally Posted by Michael TLV View Post

Greetings

None ... the controls are in the service menu. Gamma 1/2/3/4/5/6 which might work right or not.

regards

Thanks for responsing. But, where is the service menu? Is the service menu in my TV? I am confused. I am using the LC46D82U and I do not see a service menu on my TV.

Thanks,

Manny
post #134 of 258
Thread Starter 
Service menus are sometimes hidden on consumer great TVs. Your best bet to ask in the forum where your TV is discussed on how to get into the service menu and what the RGB control names are. Or use the forum search feature.

Your TV seems to be a 46" 1080p LCD so that would be the "LCD Flat Panel Displays" forum: http://www.avsforum.com/avs-vb/forumdisplay.php?f=166

You're likely not the first user of your TV wondering how to get into the service menu.

Kal
post #135 of 258
Hi Kal

I'm sure that you are by now pretty sick of people thanking you, kissing your feet in the street, begging to have your babies etc., but I just had to post saying thank you. You guide encouraged me to buy an eye one last week and calibrate my VW60. What a difference! It's also great to have some understanding of all the graphs and terminology I've been viewing (and totally confused by) for all these years.

Keep those feet washed, if I ever meet you, I'm likely to do some kissing
post #136 of 258
Thread Starter 
Thanks for the compliments and glad you liked the guide! I'll make sure to try and keep my toes clean just in case.

Kal
post #137 of 258
Thread Starter 
I've had a lot of people as why this Greyscale & Colour Calibration for Dummies guide hasn't been made a sticky thread here since everyone seems to find it extremely useful (that part I can't comment on as I'm biased).

I can only imagine it's because the entire contents isn't all within the thread itself (I have it elsewhere as it's just easier to manage for me - sorry). If anyone knows otherwise let me know...

Kal
post #138 of 258
Sorry guys I dont know what Im doing wrong, I need help!

Ive installed the sofware for my Spyder2 and the sofware for HCFR, Ive followed the instructions from Calibration for Dummies but......

Im wanting to calibrate my LCD projector using the system but I can only get up to the first part where you CLICK on the Green "GO" arrow and everytime this appears.

"CVSpyder DLL not found. Cannont use SpyderII devise. This DLL can be found in probe software installation directory. Please copy it inside HCFR colorimeter installation directory."

I really dont understand what this is?

Im sure this is simple and i know someone can help me past this hurrdle

Many thanks in advance.
post #139 of 258
Thread Starter 
Quote:
Originally Posted by RapalloAV View Post

"CVSpyder DLL not found. Cannont use SpyderII devise. This DLL can be found in probe software installation directory. Please copy it inside HCFR colorimeter installation directory."

I really dont understand what this is?

You didn't do Steps 1.2 or 1.3 (or both) from my guide.

Step 1.2 has you download and install the Spyder2 software.
Step 1.3 has you copy the Spyder2 driver over to the ColorHDFR directory.

See the guide and make sure you're doing these steps as documented.

Good luck!

GREYSCALE & COLOUR CALIBRATION FOR DUMMIES: http://www.curtpalme.com/forum/viewtopic.php?t=10457

Kal
post #140 of 258
Hi Kal, I'm enjoying going through your guide. Question on gamma - if the gamma is too high, or too low (as in my case), is there any way to improve the gamma using only contrast/brightness/RGBhighEnd/RGBlowEnd controls? (There is no gamma adjustment in my set, Panny PZ800U). Thanks!
post #141 of 258
Thread Starter 
Quote:
Originally Posted by jblevin View Post

Hi Kal, I'm enjoying going through your guide. Question on gamma - if the gamma is too high, or too low (as in my case), is there any way to improve the gamma using only contrast/brightness/RGBhighEnd/RGBlowEnd controls? (There is no gamma adjustment in my set, Panny PZ800U). Thanks!

Nope!

You need to come out of black faster on the low end and none of those controls will give you what you need.

Kal
post #142 of 258
Quote:
Originally Posted by joikd View Post

Has anyone had any trouble because of an anti-glare screen? I have a Mits. RPTV (65813) that I directly attached the Eye-One probe to the anti-glare screen. Well, the HCFR software is way off on color and tint. I ended up adjusting by eye with AVIA. HCFR showed me being totally off even though I know I was pretty darn close.

When I tried adjusting the primaries with my Lumagen HDP, I was unable to get the x/y's correct no matter what I tried. Again, I used AVIA for blue, red, and green saturation and hue, and just eyed-it. It came out pretty close, but HCFR said that it was way off.

Maybe I should try putting the probe on a tripod? It doesn't make sense to me to take the anti-glare screen off, do the measurements, then put the anti-glare screen back on. This would affect the picture. Correct?

If your I1 is not a Pro (spectroradiometer), then it really isn't that good at color adjustment anyway. Fine for grayscale, just not color decoder or CMS stuff. Use the set's "blue-, red-, and green- only" modes in the x259 menu along with color patterns for setting color and tint.
post #143 of 258
Thread Starter 
Quote:
Originally Posted by Rolls-Royce View Post

If your I1 is not a Pro (spectroradiometer), then it really isn't that good at color adjustment anyway. Fine for grayscale, just not color decoder or CMS stuff.

Why?

Kal
post #144 of 258
Quote:
Originally Posted by kal View Post

Why?

Kal

Hi, Kal. I've seen it posted elsewhere on these forums-and was surprised-that tristimulus colorimeters are not as good for precise color measurement (CMS adjustments, etc.) as they are for grayscale. As I understand it, their filters are balanced for breaking down or separating white light in a particular range of color temperatures, and as one moves away from white toward the corners of the display's gamut (primaries), these filters become less effective. This makes the meter's results for primaries and secondaries less accurate than those it reports for grayscale.

As I said, I was surprised by this. I've been using various tristimulus meters for a long time now. But because my displays don't have CMS capability, I only used them to measure and report primaries and secondaries, not to adjust them. I use single-color mode or an oscilloscope for that.
post #145 of 258
Thread Starter 
Thanks! Very interesting.

I think one thing that people have to keep in mind is that the 'inaccuracy' we're dealing with here is likely pretty low by most people's standards.

If you're paying someone to calibrate your display then by all means you'd hope they don't show up with a only a $150 Display 2 or a even only a $400 Chroma 5. You'd *hope* they'd have at least an Eye One Pro ($700) or something better.

Now, when buying for yourself, it becomes a question of what's worth it to the individual: Is it worth paying 3-4 times the price (or more) to get what in most cases will likely only be a few percentage points of more 'accuracy'? Only the person holding the purse strings can answer that. Of course, the better metters do other things better too like stay accurate longer and have the ability to NIST certified ... and so on).

Since I'm somewhat involved (in a sideways manner) in this industry, I'd be very happy to see everyone buy an Eye One Pro instead of a Display 2 !

Kal
post #146 of 258
I totally agree with you, Kal. And I probably wouldn't have chimed in until I saw that he was trying to use his Lumagen to adjust his set's primaries to specific x,y points, with poor results. Combine the possible inaccuracy of a tristimulus meter used in this manner with the peculiarities of the Mitsubishi color decoder setup, and it's no wonder the poor guy's having some problems.
post #147 of 258
Thread Starter 
Quote:
Originally Posted by Rolls-Royce View Post

I totally agree with you, Kal. And I probably wouldn't have chimed in until I saw that he was trying to use his Lumagen to adjust his set's primaries to specific x,y points, with poor results. Combine the possible inaccuracy of a tristimulus meter used in this manner with the peculiarities of the Mitsubishi color decoder setup, and it's no wonder the poor guy's having some problems.

Good point. Very true. If there's one thing that stuck in my head from Engineering school it's that errors are cumulative!

Kal
post #148 of 258
Quote:
Originally Posted by Rolls-Royce View Post

...
As I said, I was surprised by this. I've been using various tristimulus meters for a long time now. But because my displays don't have CMS capability, I only used them to measure and report primaries and secondaries, not to adjust them. I use single-color mode or an oscilloscope for that.

Can anyone explain (or refer me somewhere that could explain) how an oscilloscope could be used to do this?

I have access to one (albeit ancient) and assuming I could verify it operates properly I might give it a whirl...
post #149 of 258
Quote:
Originally Posted by Cristo View Post

Can anyone explain (or refer me somewhere that could explain) how an oscilloscope could be used to do this?

I have access to one (albeit ancient) and assuming I could verify it operates properly I might give it a whirl...

I've done this with my Mitsubishi CRT RPTV. I'm describing this from memory, so some of the details may not be correct, but here goes. You feed the display a particular color bar pattern, and attach the scope probe to a test point on the blue crt's drive card. The colorbars will produce a stairstep trace on the scope, and you adjust color to equalize the steps for the white and blue bars, and tint to equalize the steps for the cyan and magenta bars. If you have red and green controls in the decoder (NOT cuts and drives), you can do the same thing on the red and green CRTs to eliminate red and/or green push. CraigR on this forum did a how-to writeup on this for Mits owners on another forum several years ago, and it's what I refer to. If you PM him, he may be able to provide you with a copy. You may also be able to do this with digital displays, but you'd need to find the correct test points for the scope.
post #150 of 258
"Adjust the brightness so that the Y reading of the 10 IRE window pattern measures as close as possible to 0.65% of the Y reading of the 100 IRE white pattern. For example: At 100 IRE we measured a Y value of 47.387. 0.65% of this is 47.387 x 0.0065, or a Y value of 0.308. We would therefore adjust the brightness until the Y value reads 0.308.

This sets your gamma at 2.2 for the the 10 IRE window pattern which is typically the perfect gamma value as explained previously. "

My question is, can you use this meathod in reverse to find the correct contrast relative to brightness? For example, if 10 IRE Y value is .308, can you divide by .0065 to obtain the correct value of Y for 100 IRE to set contrast?? I think that would be much easier since it's easier to set brightness w/ pluge than it is to set contrast... Does this even have anything to do with contrast? The way to set contrast is described as getting into the range of 30-40 ftl, which is a bit vague. The reason I'm asking is because my gamma curve is lower than it should be, and drops off dramatically above 80 IRE or so...
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