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Official JVC RS20 / HD750 Calibration and CMS thread (NEW FIRMWARE V1.1)

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#1 ·
[EDIT 06-05-09: I have edited this first post to add some info from the first calibration thread and to make it a useful table of content to the new calibration and CMS thread]


This thread is a continuation of the original official RS20/hd750 calibration and CMS thread here http://www.avsforum.com/avs-vb/showt...8#post15314888 .


As the old calibration thread is mostly obsolete regarding CMS calibration with the arrival of the new firmware, we have decided to start afresh!


First things first, you need to upgrade the firmware before using the tips available in this thread.


A - NEW FIRMWARE

Where to get the firmware update (and common installation issues): http://www.avsforum.com/avs-vb/showt...8#post16355768

CAUTION: the new firmware erases ALL settings, so if you have general settings or calibration settings you wish to keep, make sure you make note of them before upgrading.


There is a wealth of knowledge regarding greyscale and gamma calibration in the original calibration thread. So here is a list of the most important posts which are still mostly relevant with the new firmware:


B - GREYSCALE: (from original thread, but info still relevant)

Before we get into CMS settings, the first thing to do is to get the best possible greyscale using only color temps adjustments, as this will make a huge difference with THX (and other presets). As already reported, some excellent tips are available here to achieve this from Mark Petersen Official JVC RS20 / HD750 Calibration and CMS thread - Page 22 - AVS Forum and also from Googer and others in the rest of the thread, here is one of Googer's great posts about gamma: http://www.avsforum.com/avs-vb/showt...#post15522847]


C - TWEAKED THX (from original thread, but info still relevant)

Once you have a custom color temp that gives you as perfect a greyscale as possible, the next step is to select the THX preset and enter the service mode (up/down/right/left/enter as fast as possible, either on the remote or the pj). [DISCLAIMER: be very careful when in this mode, you enter it at your own risks, if you make a mistake, don't blame me!]. You can then select a different color temp (for example the custom one you've just tweaked
), and this will be the color temp used by THX. You can now exit the service mode. This will make a HUGE difference to the ootb THX preset, as it will use a greyscale which is likely to be pretty good from 30 IRE up to 100 IRE, instead of a greyscale which is quite flat but off badly over the whole range, whether in normal or high lamp. More info about achieving this here Official JVC RS20 / HD750 Calibration and CMS thread - Page 29 - AVS Forum


If you like this "tweaked THX" preset, which is very close to rec709 - although slightly undersaturated for some - with a standard gamma, you can stop here and enjoy your PJ. If you do find it undersaturated, you can add anything from 1 to 12 - depending on your taste - to the general color control (I personally add 1-5 depending on source). That's it. Job done.


If you want to go one step further, and be able to use a custom gamma, sharpness and detail enhancement controls and adjust the gamut to Rec709, SMPTE-C or to your own taste, then have fun with the next section which is mostly about custom CMS settings...


D - CUSTOM SETTINGS, REPORTS and CALIBRATION TIPS with the NEW FIRMWARE


As members post reports/settings and calibration tips in the thread, I'll try to update this section with the most significant contributions (in chronological order).

Please let me know if I have forgotten something or if I get sloppy updating...


Reports from the pros:

GregR : http://www.avsforum.com/avs-vb/showt...7#post16360087

Tom Huffman: http://www.avsforum.com/avs-vb/showt...3#post16383023

Tom Huffman#2: http://www.avsforum.com/avs-vb/showt...9#post16431819

Settings:

Manni01 (1.4 gain screen): http://www.avsforum.com/avs-vb/showt...7#post16365507

JeffY: http://www.avsforum.com/avs-vb/showt...3#post16371803

Karrih: http://www.avsforum.com/avs-vb/showt...4#post16380924

008: http://www.avsforum.com/avs-vb/showt...9#post16383359

Nelson4u: http://www.avsforum.com/avs-vb/showt...7#post16388557

Ignace: http://www.avsforum.com/avs-vb/showt...7#post16389657

LovingDVD: http://www.avsforum.com/avs-vb/showt...6#post16482286

Lawguy: http://www.avsforum.com/avs-vb/showt...2#post16428562

Manni01 (1.2 gain screen): http://www.avsforum.com/avs-vb/showt...1#post16431351

MarcelW: http://www.avsforum.com/avs-vb/showt...9#post16433669

Lawguy LT vs i1Pro http://www.avsforum.com/avs-vb/showt...8#post16438408

RickS (HDMI Enhanced): http://www.avsforum.com/avs-vb/showt...4#post16630004

Manni01: back to 1.1 gain/new lamp, and HDMI Enhanced, settings for Rec709 and SMPTE-C http://www.avsforum.com/avs-vb/showt...0#post16662220

Manni01: updated Rec709 and SMPTE-C calibrations, along with a PAL calibration: http://www.avforums.com/forums/dlp-l...ml#post9767111

Calibration Tips:

Classic beginner's mistake and link to Tom Huffman's CMS calibration tutorial and GregR's calculator thread: http://www.avsforum.com/avs-vb/showt...3#post16370193

How to use filters to check brightness (LovingDVD): http://www.avsforum.com/avs-vb/showt...7#post16372917

When/why NOT to use filters (GregR & Tom Huffman): http://www.avsforum.com/avs-vb/showt...7#post16373717 and http://www.avsforum.com/avs-vb/showt...1#post16380651

dE discussion: http://www.avsforum.com/avs-vb/showt...5#post16374865

Tom Huffman's spreadsheet for CIELUV: http://www.avsforum.com/avs-vb/showt...7#post16378927

GregR's DisplayCalibration Calculator: http://www.avsforum.com/avs-vb/showt...2#post16382042

Get a screenshot in HCFR: http://www.avsforum.com/avs-vb/showt...8#post16383268

Which USB cable for the firmware upgrade?: http://www.avsforum.com/avs-vb/showt...7#post16383437

Training a meter to another in HCFR: http://www.avsforum.com/avs-vb/showt...4#post16384494

Adjusting greyscale (GregR): http://www.avsforum.com/avs-vb/showt...0#post16387960

Link to Calibration for Dummies: http://www.avsforum.com/avs-vb/showt...9#post16402839

Use of filter and calibration tips (Darinp2): http://www.avsforum.com/avs-vb/showt...9#post16431819

Saturation levels explained (Tom Huffman): http://www.avsforum.com/avs-vb/showt...2#post16439382

Sharpness/focus adjustment tips (GregR / LeDahu / Deanbob): http://www.avsforum.com/avs-vb/showt...2#post16689752

Great tips/tools for gamma calibration (LovingDVD / LeDahu): http://www.avsforum.com/avs-vb/showt...8#post17017488

Gamma tweaking V1.2 (english translation and VERY IMPORTANT SPECIAL PROCEDURE): http://www.avsforum.com/avs-vb/showt...9#post17045339

Gamma tweaking V2 (Le Dahu): http://www.avsforum.com/avs-vb/showt...6#post17060116

Contrast and RGB (Tom Huffman et al): http://www.avsforum.com/avs-vb/showt...8#post17150298

REST OF INITIAL POST:


I have done a first attempt with the new firmware, and the news is mostly good!


- The range for the controls has been extended from -60 to 60 (instead of -30 to 30), which gives enough range to dial the gamut perfectly without touching the general color control. Well done JVC!


- The linearity is good but not perfect. Most colors stay where they should, but green seems to be a bit oversaturated at 75% when calibrating at 100%. Nothing compared to the first firmware, but still not perfect. [edit: this was due to an error on my side, there is NO LINEARITY problem with the new firmware].


- I had only time for a quick calibration today, so I'll post more later. I attach my HCFR files for those who want to have a look at the details (EDIT: I used a brand new i1pro to calibrate).


If you want to try my settings (only after upgrading the firmware), here they are:


[EDIT: please do not use these settings, I and others have posted updated settings, see links above].


Contrast=0

Brightness=0

Color=0

Tint=0


Color temp (new lamp, probably not useful for most of you)

Gain R=-24, G=0, B=-54

Offset R=-1 G=-3 B=0


CMS (H,S,B)

Red -4 -23 7

Yellow 22 -44 38

Green -5 -39 44

Cyan -3 -48 39

Blue 37 -8 -4

Magenta -6 0 -3


I didn't have time to do any fine-tuning on gamma etc...

 

New firmware.zip 153.3935546875k . file



 

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#1,357 ·
Mike .. in my past experience with JVC and lamps, I noticed that lamps become more stable e realable around the 100 hours, so this could be the age time to get a professional ISF calibration


Anyway, I noticed too the it will needs to be re-touched after the 350-450 hours, but surely after the 500 hours if you need the best and reference results.
 
#1,358 ·
I've had a strange problem: in using the new ChromaPure video calibration package with my RS20 I've gotten everything to work fine (and boy, is the CMS a charm to use--so accurate and so simple!) EXCEPT the Custom Gamma step. After running the gamma 'base line' measurement, when I go to a specific IRE, e.g., 90%, and start 'Continuous Measurement', when I bump the gamma up in the custom gamma feature on RS20 up just one point, it jumps to an enormous value, i.e., from ~ 2.2 or 2.3 up to ~ 5 or 6, and the gamma curve just goes straight up! I'm clearly doing something wrong, not understanding what's going on.


In the RS20 custom gamma, I'm selecting 'White' before going to the point by point gamma adjustment. Should I be doing something else? Thanks for any suggestions/advice.


Bill
 
#1,359 ·

Quote:
Originally Posted by millerwill /forum/post/18369994


I've had a strange problem: in using the new ChromaPure video calibration package with my RS20 I've gotten everything to work fine (and boy, is the CMS a charm to use--so accurate and so simple!) EXCEPT the Custom Gamma step. After running the gamma 'base line' measurement, when I go to a specific IRE, e.g., 90%, and start 'Continuous Measurement', when I bump the gamma up in the custom gamma feature on RS20 up just one point, it jumps to an enormous value, i.e., from ~ 2.2 or 2.3 up to ~ 5 or 6, and the gamma curve just goes straight up! I'm clearly doing something wrong, not understanding what's going on.


In the RS20 custom gamma, I'm selecting 'White' before going to the point by point gamma adjustment. Should I be doing something else? Thanks for any suggestions/advice.


Bill

The good news is that with great care, patience, and time - you can use the custom gamma menu in the RS20 to dial in the gamma. And although it may take you several hours, it is worth every bit of it when you see what a huge difference this will make (flat picture otherwise after the pj gets a few hundred hours on it, if not sooner).


The not so good news is that the custom gamma menu is extremely finicky and you have to understand its quirks and how to "trick it" into using the values you want. It does not work well for setting one point at a time, measuring, and setting the next point. Rather it works best if you know all the numbers you want to set in advance.


The best thing I can recommend at this point is to search for leDahu's spreadsheet that he posted here months ago. That contains one way to calculate and calibrate gamma all in one run through, rather than one point at a time, which plays well to how the custom gamma menu tweaks work best. Around the same time as that posting, leDahu also posted a text file with instructions on how to manipulate ("trick") the custom gamma menu into using the values you want. A must read for sure.


The other not so good news is that the gamma calibration drifts MUCH quicker than most people realize. For instance in my case I can tweak for 6-7 hours to get the gamma nearly perfect. However within a short amount of bulb hours the calibration and gamma has already drifted, negating a great deal of all the work I had just done. My advise is to get it close but not worry about getting it perfect, and plan to do it often. Its a ton of work but well worth the effort.
 
#1,360 ·
Thanks, as always, for your good advice, l'dvd. I actually like the RS20's preset gamma A. It stays very close to 2.3 across most IRE, dipping down to ~ 2.1 at 10%, thus giving better resolution of the features in the darkest scenes. So I may simply not sweat customizing Gamma and going this route.


It is correct, isn't it, to choose 'White' when trying to use the point-wise customization in the RS20?
 
#1,361 ·

Quote:
Originally Posted by millerwill /forum/post/18372886


Thanks, as always, for your good advice, l'dvd. I actually like the RS20's preset gamma A. It stays very close to 2.3 across most IRE, dipping down to ~ 2.1 at 10%, thus giving better resolution of the features in the darkest scenes. So I may simply not sweat customizing Gamma and going this route.


It is correct, isn't it, to choose 'White' when trying to use the point-wise customization in the RS20?

I would be quite surprised if one of the standard gammas (such as Gamma A you mentioned) has not drifted considerably, knowing that you have at least a few hundred hours on your unit.


My guess is that if you measure this gamma, you will see that it falls off deeply starting around the 80% range and by 95% is nearly off the chart.

The proper way to see this is on a gamma chart (not on the luminance histogram which shows an exponential curve).


If you can measure your gamma and post the gamma chart here I would like to see it. Unless your gamma is indeed still in tact I would highly recommend correcting it with leDahu's process. It will restore the deep dimensionality to the picture.


To answer your question about RGB in the gamma versus W, the answer is that it depends. Technically speaking if the dE is correct at a certain level but the gamma is not, you can use just W to correct the gamma. However there is typically some interaction, so tweaking W may cause the dE to shift. In which case you can compensate by tweaking RGB accordingly. However in doing so, that can cause the gamma to shift, either back toward the way it was or in the other direction. So like many things calibration-wise it can be a delicate balancing act.
 
#1,362 ·

Quote:
Originally Posted by lovingdvd /forum/post/18373283


I would be quite surprised if one of the standard gammas (such as Gamma A you mentioned) has not drifted considerably, knowing that you have at least a few hundred hours on your unit.


My guess is that if you measure this gamma, you will see that it falls off deeply starting around the 80% range and by 95% is nearly off the chart.

The proper way to see this is on a gamma chart (not on the luminance histogram which shows an exponential curve).


If you can measure your gamma and post the gamma chart here I would like to see it. Unless your gamma is indeed still in tact I would highly recommend correcting it with leDahu's process. It will restore the deep dimensionality to the picture.


To answer your question about RGB in the gamma versus W, the answer is that it depends. Technically speaking if the dE is correct at a certain level but the gamma is not, you can use just W to correct the gamma. However there is typically some interaction, so tweaking W may cause the dE to shift. In which case you can compensate by tweaking RGB accordingly. However in doing so, that can cause the gamma to shift, either back toward the way it was or in the other direction. So like many things calibration-wise it can be a delicate balancing act.

I have over 1000 hrs on this lamp. When I select gamma A, it measures ~ 2.3 +/- .05 from 20 to 100%, but falls to ~ 2.1 at 10%.


Yes, I did see your and leDahu's discussions several weeks ago, but I'm afraid it was mostly beyond me. That's why I find ChromaPure so appealing, it's simplicity.


What I find so weird is how the point-wise gamma adjustment is so wildly sensitive when I try to move the gamma value by the minimal increment. Either ChromaPure is not reading what I think it's reading in its 'Continuous Measurement' mode, or something else.
 
#1,363 ·

Quote:
Originally Posted by millerwill /forum/post/18373778


Either ChromaPure is not reading what I think it's reading in its 'Continuous Measurement' mode, or something else.

Bill, as I pointed out earlier, all the program is doing is doing is reading the light output at whatever level of stimulus the test pattern provides.


It just sounds like your unit's custom gamma controls are too sensitive for fine adjustments. Try it again and ignore the gamma position and just take note of the change in output level (cd/m2 or fL). How much does it change when you move the custom gamma control a single click? You can also test this in the raw data module.
 
#1,364 ·

Quote:
Originally Posted by TomHuffman /forum/post/18374100


Bill, as I pointed out earlier, all the program is doing is doing is reading the light output at whatever level of stimulus the test pattern provides.


It just sounds like your unit's custom gamma controls are too sensitive for fine adjustments. Try it again and ignore the gamma position and just take note of the change in output level (cd/m2 or fL). How much does it change when you move the custom gamma control a single click? You can also test this in the raw data module.

Yes, thanks, Tom. I was simply 'trolling' to see if there were some RS20 owners who had successfully used its pointwise gamma function with ChromaPure, to give me some tips.
 
#1,365 ·

Quote:
Originally Posted by millerwill /forum/post/18374173


Yes, thanks, Tom. I was simply 'trolling' to see if there were some RS20 owners who had successfully used its pointwise gamma function with ChromaPure, to give me some tips.

I have calibrated several of these and have not run across this problem. I wouldn't assume that you are doing anything wrong. It just sounds like your unit has a problem.
 
#1,366 ·
I used the spreadsheet posted back on the first page of this thread to work out what my custom gamma values should be and it still took me ages sorting it out. Since I've got my VideoEQ Pro I've just set the custom gamma to default and used the controls in the VideoEQ to set gamma (like Millerwill I'm using Chromapure) step by step down from 95 IRE. It's so much easier than the JVC controls, so I'm more likely to do it frequently. Side benefit is that I can shift my gamma in 0.1 increments by simply changing the JVC's custom gamma using a default 2.1/2.3 or whatever setting.


If only the JVC controls were as easy to use, I found them very frustrating given how quickly the gamma drifts.
 
#1,367 ·

Quote:
Originally Posted by TomHuffman /forum/post/18374581


I have calibrated several of these and have not run across this problem. I wouldn't assume that you are doing anything wrong. It just sounds like your unit has a problem.

Very interesting, Tom. So when you use the Custom gamma feature of the RS20's, where you can move the gamma value pointwise, I assume that you first click W (white), and not R, G, or B, right? And when you move gamma up or down at one IRE point, this moves in the 'Continuous Measurement' mode of ChromPure, accordingly?
 
#1,368 ·

Quote:
Originally Posted by millerwill /forum/post/18377596


Very interesting, Tom. So when you use the Custom gamma feature of the RS20's, where you can move the gamma value pointwise, I assume that you first click W (white), and not R, G, or B, right? And when you move gamma up or down at one IRE point, this moves in the 'Continuous Measurement' mode of ChromaPure, accordingly?

Yes. I have never had any problems here. I did one fairly recently.


I recommend that you experiment as I suggested earlier. Go into the raw data module. Take a reading at, say, 90% stim. Record the Y value. Take another reading after moving the custom gamma up or down one click at the 90% point. How much different are the Y values?


I agree with others that the gamma drifts, but I have not seen this very large change with only small changes in adjustment.
 
#1,369 ·
Observation: I know that it is recommended to calibrate by taking light readings off the screen, but I have recently done grayscale and CMS on my RS20 (using ChromaPure) two ways, 1) taking the readings with a Display2LT, trained to my I1Pro, off the screen, and 2) taking the readings directly from the RS20, with the I1Pro about 2-3 ft away (with its diffuser cap on, of course).


The GS and CMS #'s are similar, though of course not identical, and when looking at test material I find that I actually prefer the results from method (2). I would be curious to know what other people's experiences are on this issue. (FWIW, I note that when UMR calibrated my RS20 originally, he took readings directly from the pj!)
 
#1,370 ·

Quote:
Originally Posted by millerwill /forum/post/18383306


Observation: I know that it is recommended to calibrate by taking light readings off the screen, but I have recently done grayscale and CMS on my RS20 (using ChromaPure) two ways, 1) taking the readings with a Display2LT, trained to my I1Pro, off the screen, and 2) taking the readings directly from the RS20, with the I1Pro about 2-3 ft away (with its diffuser cap on, of course).


The GS and CMS #'s are similar, though of course not identical, and when looking at test material I find that I actually prefer the results from method (2). I would be curious to know what other people's experiences are on this issue. (FWIW, I note that when UMR calibrated my RS20 originally, he took readings directly from the pj!)

The diffuser that comes with the I1 isn't any good for grey scale. The image will be shifted towards red way too much. You need to point it at the screen without the diffuser if using an I1 probe. I liked the results much more pointed at the projector but using a Spyder2 probe for grey scale. The light intensity is much higher and you get better results visually. My screen is an angular refective high gain model and each RGB level shifts too much pointing the probe off axis. Pointed at the screen doesn't work with my screen.


Ron
 
#1,371 ·

Quote:
Originally Posted by Ronomy /forum/post/18384733


The diffuser that comes with the I1 isn't any good for grey scale. The image will be shifted towards red way too much. You need to point it at the screen without the diffuser if using an I1 probe. I liked the results much more pointed at the projector but using a Spyder2 probe for grey scale. The light intensity is much higher and you get better results visually. My screen is an angular refective high gain model and each RGB level shifts too much pointing the probe off axis. Pointed at the screen doesn't work with my screen.


Ron

Would a good diffuser from a photo shop work with the i1 if a good optical seal can be made to the edges of the i1? I'd like to calibrate directly from the pj too but have heard of this i1 diffuser problem before.
 
#1,373 ·

Quote:
Originally Posted by erkq /forum/post/18384795


Would a good diffuser from a photo shop work with the i1 if a good optical seal can be made to the edges of the i1? I'd like to calibrate directly from the pj too but have heard of this i1 diffuser problem before.

Maybe but I would think you still need to have it calibrated with the diffuser for best results. If you find one let me know. Pointing the I1 at the projector is not stable. RGB shifts too much with very small movement of the I1.
 
#1,376 ·

Quote:
Originally Posted by millerwill /forum/post/18383306


The GS and CMS #'s are similar, though of course not identical, and when looking at test material I find that I actually prefer the results from method (2).

There is nothing wrong with taking measurements from the lens using a diffuser. It does allow higher light levels. However, if you do so the readings should be color corrected from measurements taken off the screen. Otherwise, part of your results will be artifacts introduced by the diffuser and you will miss whatever contribution the screen's own characteristics impart to the image.


This is not a rigid recommendation about standards so much as simple common sense. When you watch content, you are watching light that is reflected off the screen, not light that comes out of the lens filtered through a diffuser.
 
#1,377 ·

Quote:
Originally Posted by TomHuffman /forum/post/18385068


There is nothing wrong with taking measurements from the lens using a diffuser. It does allow higher light levels. However, if you do so the readings should be color corrected from measurements taken off the screen. Otherwise, part of your results will be artifacts introduced by the diffuser and you will miss whatever contribution the screen's own characteristics impart to the image.


This is not a rigid recommendation about standards so much as simple common sense. When you watch content, you are watching light that is reflected off the screen, not light that comes out of the lens filtered through a diffuser.

Tom, what you say is obviously correct and certainly makes sense. I specifically asked UMR about this when he calibrated my pj almost a year ago, and he said that the effect of the screen was minimal and less than the inherent errors in the calibration process. These comments may have been specific to my type screen; I would certainly expect a gray screen, e.g., to have a noticeable effect.
 
#1,378 ·

Quote:
Originally Posted by TomHuffman /forum/post/18385068


There is nothing wrong with taking measurements from the lens using a diffuser. It does allow higher light levels. However, if you do so the readings should be color corrected from measurements taken off the screen. Otherwise, part of your results will be artifacts introduced by the diffuser and you will miss whatever contribution the screen's own characteristics impart to the image.


This is not a rigid recommendation about standards so much as simple common sense. When you watch content, you are watching light that is reflected off the screen, not light that comes out of the lens filtered through a diffuser.

Well, sure... I was willing to assume the screen is white, even if it isn't... close enough. But I like the idea of measuring the screen [EDIT] through the diffuser [/EDIT] to correct for them. This can be done at bright levels where the cheap i1 works as well as it can. Then the screen corrected i1 can be turned to the pj for the lower level measurements.



I assume Chromapure has a facility for entering this adjustment measurement?
 
#1,379 ·

Quote:
Originally Posted by millerwill /forum/post/18385123


I specifically asked UMR about this when he calibrated my pj almost a year ago, and he said that the effect of the screen was minimal and less than the inherent errors in the calibration process.

This is testable. What the difference in xy readings using a 80% white test pattern when measured from the lens with diffuser and then taken directly off the screen without diffuser?
 
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