Official JVC RS20 / HD750 Calibration and CMS thread (NEW FIRMWARE V1.1) - Page 8 - AVS Forum
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post #211 of 1634 Old 04-30-2009, 02:45 PM - Thread Starter
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Quote:
Originally Posted by stereomandan View Post

Manni01,

I took a look at your calibration and the lower saturations look great. Thanks for measuring the 30 saturation windows. JVC certainly did a stellar job with the CMS on this attempt! You can really nail the calibraiton with this projector and know that you are getting the best picture possible.

Dan

You're welcome, thanks a lot for the feedback Dan.
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post #212 of 1634 Old 04-30-2009, 03:00 PM
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Hi,

I have some more questions, maybe they are not all related to the DLA-RS20, but at least it is my intention to put the JVC at its best performance...

- Since I currently don't own (yet) a Blu-Ray player I want to perform a temporary calibration for SDTV, being the 601 standard. I know that the primary colors are almost equal (only x for green is 0.29 instead of 0.30), but what luminance values I have to use for the primaries and the secondaries? Keeping in mind that today my DVD player is performing the YUV to RGB conversion and sending it over through DVI to the JVC.

- I'm using the "standard" range on the DVI (RGB colorspace); being 16-235. However I noticed that the JVC is clipping on specular highlights on the demo footage on the DVE DVD, as well as on the graybars (the white only). Since I don't want to use DVI in "enhanced" mode (0-246), because of contouring artifacts, I put the JVC in enhanced mode and adjusted the brightness to -7 to get black (16) to real black (not seing blacker-then-black) and the contrast to +11 to get "highlight" white (a bit higher then 235 I assume) at white of the JVC. Why? Because it looked to me that the JVC throws away everything higher then 235, even if you lower the contrast. Did other people notice similar behaviour?

- Are the full screen primary and secondary color test patterns on the DVE DVD 100% saturated?

- What are the most recommended DVD and eventually Blu-Ray disks for performing calibrations? Where can they be ordered?

- Is the gamma calibrations performed using the standard menu system, or did some people use service (factory) menu's?

- Is there an inherent difference between profiles Cinema2, Natural and User1-3? If yes, what is the preferred profile for performing a calibration on?

- What gamma setting is recommended for wathing movies; gamma "B" or gamma "Normal" or another one? Or is it recommended to create a user one? I read somewhere that B is very close to gamma 2.2?

Hope to get some reactions on these...

Thanks in advance!

Ignace.
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post #213 of 1634 Old 04-30-2009, 03:02 PM - Thread Starter
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Quote:
Originally Posted by JeffY View Post

Here are my "my Spyder 3 is colour blind, I'll use my eyes instand settings"

R -4,-22,11
Y 5,-44,37
G -6,-42,35
C -2,-46, 37
B 6, -4, 3
M -2,-4,0

I've tried your settings tonight, while watching Elisabeth (the movie, that's not my wife's name), and I did a few tests with Cars, Tropic Thunder and Wall-E.

The results are extremely similar to my settings, I wouldn't be able to tell them apart by eye, except for blue of course, which is brighter on yours, for example in the spaceship scenes in Wall-E (in the control room). I do not see a huge change in hue, but that may be due to my eyes or the material I screened.

When I recalibrate next week, I'll ty to keep a close eye on blue.

For now, I'll stick to my settings, which really look great on my PJ.
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post #214 of 1634 Old 04-30-2009, 03:06 PM - Thread Starter
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Quote:
Originally Posted by karrih View Post

I also used Mannis settings for a while and about only weakness I noticed today was slightly unnatural sky color, much like you describe.

Could you please tell us in which movie (with a precise timecode if possible)? I checked the sky in Tropic Thunder and Elisabeth and couldn't see anything weird, at least on my PJ.

It would be interesting to compare my settings and Jeff's on the scene where you felt the sky was unnatural.

Also I saw a difference in blue, but no real difference in cyan.

This being said, my eyes are about 10% of Jeff's when he closes his, so I wouldn't be surprised if I simply can't see it. I'm very sensitive to red and a bit less to green, but not that much to blue.
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post #215 of 1634 Old 04-30-2009, 03:11 PM
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Originally Posted by lovingdvd View Post

First - run, do not walk, to your color filters. I am excited about this for you. It will tell you definitively which (if any?) of your Y values are incorrect.

Its been a while since I used these and I've never really had a completely solid grasp on it, but I'll try to explain it at a very high level here. Then hopefully someone else can chime in...

Basically take your RGB filters from DVE but use the AVS HD 709 1.2 patterns. The patterns you want are the ones that look like vertical color bars with blinking color blocks in various places within and above the bars.

This is all from memory and may be rough but the general idea is this - start with the blue filter and hold it up to one eye while closing the other one. Look at the blue bar on the screen from your normal seating distance.

If the Y value is correct, then the blinking (white?) blocks should be virtually invisible and the bar should look solid blue while viewing through the filter. To give you an idea of what a WRONG Y setting looks like, take the Brightness for Blue and crank it up or down a lot on purpose just to watch what happens with the filter. The correct/ideal setting is the one where the white blends the most into the blue.

Then you can repeat this for red and green, switching filters accordingly (use red filter to view red bar, green filter to view green bar). I think the secondaries can be done too but would have to play with the pattern to recall how.

My understanding is that this technique is considered to be quite accurate and my recommendation, especially in your case where this is confusion over which if any meter to try, is to dial in Y based on the filter and forget about the meter for now.

Bottom line is that regardless of what your meter tells you, the setting can only be right if it looks right through the filters. I think this will be a VERY interesting experiment for you, as it will give you an idea of which of your meters is most accurate in this regard, as well as tell you where the correct setting is!

Keep us posted on what you find - I am very curious to hear the results.

Hopefully someone with more experience using these filters will chime in and provide more details on the technique as well, but this should get you started.

LovingDVD,
I loaded in what Manni calls his third attempt settings when I reported how they looked on my projector.

You mention that DVE can be used for this Filter method.
I used the the DVE color filters approach with DVE color bars to look at the color decoder behaviors (for example all color bars containing blue should exactly match the white background when viewed through a blue filter--etc.) . Am I correct in assuming the filter method you are describing is essentially also looking at color decoder errors as you adjust by eye for the correct Y values.

If so, In trying out Manni's settings, I made a mistake in trimming the Main Color and Tint controls away from 0,0 while looking through the filters in an attempt to compensate for the color decoder errors. ( I have no meter and understand the color decoder is not part of the CMS, but I am having some success using these make-do methods).
What I apparently should have done is to correct the Y values of Blue, Red and Green with the CMS Y values as you describe instead of trimming the Main Color and Tint controls. Is that anywhere near correct?

Thanks
KT
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post #216 of 1634 Old 04-30-2009, 03:12 PM - Thread Starter
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Quote:
Originally Posted by gregr View Post

Guys,
You can use my Display Calibration Calculator to compute the dE values, and/or to find the Y values for your measured x,y points that minimize the dE error for each color. Just put in your x,y values and your Y value and click Compute to get the dE value. Then vary the Y value (in the calculator) until you minimize the dE value, and use that Y value as your target.

Greg, thanks a lot for this. I have put the results of my last clibration through your calculator (posted the results a few posts above), and found a difference between the dE you report and the dE reported by HCFR. More on some colors and some level of stimulus thaan others. Could you give us an explanation?
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post #217 of 1634 Old 04-30-2009, 04:54 PM
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Originally Posted by Manni01 View Post

Greg, thanks a lot for this. I have put the results of my last clibration through your calculator (posted the results a few posts above), and found a difference between the dE you report and the dE reported by HCFR. More on some colors and some level of stimulus thaan others. Could you give us an explanation?

There are several (way too many) different CIE color space models that produce different dE results (very different models, very different equations, very different scales i.e. dE=1 is the JND [just noticeable difference] in all systems, but dE=2 is barely noticeable in some systems and a large error in others). I use the CIE LUV 1976 color space/dE calculations in my reviews and for the calculator. It is (I think) the favorite of us "old video engineers" for some technical reasons and because we have developed a good feel for what a 3 dE or 6 dE error means over the years. Roughly speaking, 1 dE difference can barely be detected under careful comparison conditions, a 3 dE difference is barely noticeable in real video, a 6-7 dE difference is quite noticeable in real video, and 10 dE differences are really big (unacceptable) errors to a discerning viewer. These would be my estimates for highly saturated primary and complementary colors. When measuring grayscale we drop the luminance contribution to the error (and pick that up as a gamma error) so that the given dE variances (without luminance) are much more obvious. i.e. a 1 dE deviation is the JND, but a 2 dE deviation is obvious on a grayscale test pattern, a 3 dE deviation becomes quite noticeable on a B&W film, and a 4 dE deviation is too much for me.

Anyway, I don't know what color space HCFR is using for dE calculations. Most of the programs are probably using newer color spaces (that were developed at the insistence of the paint and textile industries rather than video engineers), because newer is always better, right? That is as much as you will get me to say or argue about dE. There are lots of things worth spending my time on, and that isn't one of them. But there is lots of discussion about this topic in other threads.

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post #218 of 1634 Old 04-30-2009, 05:00 PM
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Greg,

HCFR uses the Luv 1976 dE's as well. The HCFR dE's are the same as the dE's I get calculating them with the CIE Luv method.

The CIE94 and CIELAB dE's don't match HCFR in my experience.

Dan
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post #219 of 1634 Old 04-30-2009, 05:25 PM
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Quote:
Originally Posted by stereomandan View Post

Greg,

HCFR uses the Luv 1976 dE's as well. The HCFR dE's are the same as the dE's I get calculating them with the CIE Luv method.

The CIE94 and CIELAB dE's don't match HCFR in my experience.

Dan

Then I don't know why Manni01 got different results. My calculator has been up for months and compared against other CIELUV programs so I don't think there are any errors, other than possible negligible differences that can occur from using different precision arithmetic.

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post #220 of 1634 Old 04-30-2009, 06:09 PM
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Originally Posted by KTTV Images View Post

LovingDVD,
I loaded in what Manni calls his third attempt settings when I reported how they looked on my projector.

You mention that DVE can be used for this Filter method.
I used the the DVE color filters approach with DVE color bars to look at the color decoder behaviors (for example all color bars containing blue should exactly match the white background when viewed through a blue filter--etc.) . Am I correct in assuming the filter method you are describing is essentially also looking at color decoder errors as you adjust by eye for the correct Y values.

If so, In trying out Manni's settings, I made a mistake in trimming the Main Color and Tint controls away from 0,0 while looking through the filters in an attempt to compensate for the color decoder errors. ( I have no meter and understand the color decoder is not part of the CMS, but I am having some success using these make-do methods).
What I apparently should have done is to correct the Y values of Blue, Red and Green with the CMS Y values as you describe instead of trimming the Main Color and Tint controls. Is that anywhere near correct?

Thanks
KT

Well I'm not so sure since Greg was saying it is incorrect to use this method for Brightness adjustment within a CMS, and I think I understand why based on his explanation. However I believe it is valid for checking/correcting the color decoder. I'll leave it to someone else to answer your questions since I am not sure.
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post #221 of 1634 Old 04-30-2009, 06:13 PM
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Originally Posted by gregr View Post

If you want to use a primary or complementary that is different from your (otherwise) standard target, i.e. if you want Rec 709 except for a more saturated red, or perhaps you want all of the primaries a little more saturated, then you are on your own when adjusting a CMS. There is no reason to then expect a particular relationship between the x,y points and their Y values to somehow be better than some other relationship. i.e. you have purposely deviated from a one-to-one color mapping between the source and display, so there is no way to then say what the "best" choice will now be for x,y and Y values except what looks good to you. You changed the x,y points because they looked better to you, so pick the Y values that also look best you too.

What some people seem to find confusing about the Display Calibration Calculator is that they don't realize it is simply a tool to make certain types of calculations when those calculations are relevant to your objective. If you are not targeting a standard colorimetry with a CMS, then the xyY relationships between the primary and complementary colors no longer have any physical or perceptual relevance. You basically decided to do what looks good to you so you are on your own. Practically speaking however, you may want to adjust to a standard as close as possible first, and then make minor subjective changes that please you after that, rather than simply making totally arbitrary adjustments from the start. The former is much more likely to yield more pleasant results.

So why does the calculator allow you to enter custom RGB targets, or to copy your measured RGB values to the target section?? That is apparently what confuses some people. The reason is so that you can adjust the YCbCr to RGB color decoding, NOT a CMS (or in the rare case that you have video sources based on a Standard other than Rec. 601 or SMPTE C). The Color decoding should be adjusted to the standards before adjusting a CMS. I think it is best to make sure the video signals are being converted to the correct RGB values, even if you are then going to dial in some non-standard CMS settings. The reason for that is because unless the Color Decoding is standard it can produce various non-linear effects that can degrade any CMS adjustment (even a "subjectively custom" one), and you will know what an accurately adjusted CMS would have looked like (even if you still want to modify it later).

Thanks Greg. I think I understand. Essentially you are saying there is really no correct Y value for a custom gamut since there is no reference and one is basically doing whatever they want anyway, so at that point who is to say what Y should be. Is that the gist of it?

I was thinking that a given brightness (Y) of a color, however, would have a technically correct, derivable value. Not because of the shade/coloring of a value, but because it could be too bright or too dark relative to the other colors. No?
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post #222 of 1634 Old 04-30-2009, 06:47 PM
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Ric. Aren`t the L values artificial in that they are specified by a formula in the standard for the primary values specified in the standard ts only right with respect to meeting the standard. If you reduce the value without making any changes to the sauturation or hue, the color will appear darker. But the only right is the artificial right set in the standard.

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post #223 of 1634 Old 04-30-2009, 07:14 PM
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Quote:
Originally Posted by gregr View Post

Then I don't know why Manni01 got different results. My calculator has been up for months and compared against other CIELUV programs so I don't think there are any errors, other than possible negligible differences that can occur from using different precision arithmetic.

Greg, I'll try to look into this tomorrow. I highly doubt your calculations are wrong. We'll get it sorted out.

Dan
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post #224 of 1634 Old 04-30-2009, 09:02 PM
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Originally Posted by stereomandan View Post

Greg, I'll try to look into this tomorrow. I highly doubt your calculations are wrong. We'll get it sorted out.

The discrepancies are very small.

The source is the fact that HCFR rounds its numbers to 3 decimals for display, but it uses the unseen extra digits in the dE calculation. When I used four digits I got exactly the same results. If you typed the 4-digit values into Greg's app, I'll bet you would get the same values as well.

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post #225 of 1634 Old 04-30-2009, 09:31 PM
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Originally Posted by Manni01 View Post

Could you please tell us in which movie (with a precise timecode if possible)? I checked the sky in Tropic Thunder and Elisabeth and couldn't see anything weird, at least on my PJ.

It would be interesting to compare my settings and Jeff's on the scene where you felt the sky was unnatural.

It was some silly travel program from cable and I don't have it any more. I guess it was shot with video equipment instead of film. Nevertheless, I guess I could try to check out my Blurays for this.
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post #226 of 1634 Old 04-30-2009, 10:26 PM
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Originally Posted by lovingdvd View Post

Thanks Greg. I think I understand. Essentially you are saying there is really no correct Y value for a custom gamut since there is no reference and one is basically doing whatever they want anyway, so at that point who is to say what Y should be. Is that the gist of it?

Yep, that's a lot more concise than I said it.

Quote:
Originally Posted by lovingdvd View Post

I was thinking that a given brightness (Y) of a color, however, would have a technically correct, derivable value. Not because of the shade/coloring of a value, but because it could be too bright or too dark relative to the other colors. No?

I'm sure you would find values that you didn't like because they seem too bright or too dark to you, but there is no "technically right" value since you went on your own with a subjective x,y value. Remember that it's the total combination of the x,y point and its brightness that combine to produce a perceived color. So if you could imagine a particular (non-standard) color that you wanted you could get equally close to it (same dE) by choosing a variety of x,y and Y combinations. But there is no calculation that can know what xyY color you really want, and hence no way to calculate a Y value for your x,y point.

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post #227 of 1634 Old 04-30-2009, 10:45 PM
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Originally Posted by lovingdvd View Post

However I believe it [filters] is valid for checking/correcting the color decoder.

Yes, color filters can be used for adjusting the color decoder, IF you use the projector's native primaries since in that case the luminance (Y) of the primary, complementary, and reference white colors are all strictly related, i.e. Y(White) = Y(R) + Y(G) + Y(B), Y(Yellow) = Y(R) + Y(G), Y(Magenta) = Y(R) + Y(B), and Y(Cyan) = Y(G) + Y(B), when the magnitude of the RGB signals is R = G = B. The color filters visually verify that R = G = B if you input RGB color bar signals. So when you instead input YCbCr encoded color bar signals, the filters allow you to verify that the YCbCr signals are correctly decoded back to RGB signals where R = G = B.

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post #228 of 1634 Old 05-01-2009, 03:02 AM - Thread Starter
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Originally Posted by gregr View Post

Then I don't know why Manni01 got different results. My calculator has been up for months and compared against other CIELUV programs so I don't think there are any errors, other than possible negligible differences that can occur from using different precision arithmetic.

Thanks for the explanation Greg. I couldn't find which formula the calculator or HCFR was using. Thanks to Tom for the comments and to Dan for the confirmation that HCFR uses the same formula.

Tom was right, is is primirily due to the rounding that HCFR does in displaying the information. I cut the data from HCFR and pasted it to Excel, and then to your calculator with 5 digits precision (I couldn't do it directly). The differences are gone for the primaries, but the secondaries still show a small difference.

This is probably negligeable in regard to how it can influence a calibration, I was just curious to understand why it wasn't identical given the fact it should use the same formula, and why it should affect the secondaries and not the primaries.

I attach the full numbers below.
LL
LL
LL
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post #229 of 1634 Old 05-01-2009, 04:53 AM
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Quote:
Originally Posted by TomHuffman View Post

The discrepancies are very small.

The source is the fact that HCFR rounds its numbers to 3 decimals for display, but it uses the unseen extra digits in the dE calculation. When I used four digits I got exactly the same results. If you typed the 4-digit values into Greg's app, I'll bet you would get the same values as well.

Thanks for figuring that out Tom, and for your input.

Dan
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post #230 of 1634 Old 05-01-2009, 05:41 AM - Thread Starter
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Originally Posted by stereomandan View Post

Thanks for figuring that out Tom, and for your input.

Dan

So Dan, you would say the small differences in secondaries (up to 5%) and not in primaries (identical) even with 5 digits accuracy (see post above your last) are normal?
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post #231 of 1634 Old 05-01-2009, 09:44 AM
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Originally Posted by Manni01 View Post

So Dan, you would say the small differences in secondaries (up to 5%) and not in primaries (identical) even with 5 digits accuracy (see post above your last) are normal?


Well, the way that you are looking at the error (up to 5%) makes it sound worse than what your eyes are able to notice.

Yes, there is a 5% error from one dE calculation to the other, but the overall difference in dE is only 0.2 at worst case from one calculation to the next. A dE of 1 is barely noticeable under the most scutinous viewing, so a dE of 0.2 will not be noticeable in the least. Hope that helps.

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post #232 of 1634 Old 05-01-2009, 10:24 AM
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Here's an open spreadsheet that calculates CIELUV and makes the math explicit.

 

dE-LUV.zip 30.697265625k . file

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post #233 of 1634 Old 05-01-2009, 11:43 AM
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Originally Posted by millerwill View Post

I understand that all settings go back to their initial default values after loading in the new FW, but what about the mod many made in the Service Menu that changed the THX color temp to that in User 1? Is that maintained, or does it need to be re-done?

Feedback on THX Trick:
Guys, I know this report is late --but last night I also found that the THX Color temperature trick does need to be redone (set to my Jason's calibrated Custom 1 setting).

However, with my bulb at 470 hours, I now find the Color Temperature for Jason's original low power mode has visibly drifted toward green, and at high power it has drifted toward red. I also have measured a 1 stop loss, (50% loss in brightness) due to bulb aging to this point, so I now need to run at high power.

From previous comments it looks like this is all consistent/normal with what others are finding. Does this sound correct?

KT
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post #234 of 1634 Old 05-01-2009, 12:02 PM - Thread Starter
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Quote:
Originally Posted by TomHuffman View Post

Here's an open spreadsheet that calculates CIELUV and makes the math explicit.

Thanks very much Tom, I'll use this for my next calibration.

I've spent most of the afternoon installing the new material for my screen (Seymour AV XD Center Stage) and moving my speakers behind it, and I hope to be able to calibrate tonight.
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post #235 of 1634 Old 05-01-2009, 12:03 PM - Thread Starter
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Quote:
Originally Posted by stereomandan View Post

Well, the way that you are looking at the error (up to 5%) makes it sound worse than what your eyes are able to notice.

Yes, there is a 5% error from one dE calculation to the other, but the overall difference in dE is only 0.2 at worst case from one calculation to the next. A dE of 1 is barely noticeable under the most scutinous viewing, so a dE of 0.2 will not be noticeable in the least. Hope that helps.

Dan

Thanks Dan, that's what I thought.
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post #236 of 1634 Old 05-01-2009, 12:50 PM
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I am a proud owner and really love my Sony G90 CRT projector used in a 1080p mode. It looks great on a 100" Stewart screen even with 10k+ hrs on the tubes. However, my wife and I are getting tired of looking at a Volkswagon hanging in the rafters. I've read a lot on the forums and everyone raves about the RS20/HD750, but my question is will it be a step up, down, or lateral from the G90.

The LCD sets we have purchased, including high end Sony Bravia to Vizio all look "digital" at some point and handle motion poorly.

I have all the set-up toys to do the job, I just don't want to feel as I have taken a step down.

Comments, please.

John

John
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post #237 of 1634 Old 05-01-2009, 01:07 PM
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Originally Posted by netroamer View Post

I am a proud owner and really love my Sony G90 CRT projector used in a 1080p mode. It looks great on a 100" Stewart screen even with 10k+ hrs on the tubes. However, my wife and I are getting tired of looking at a Volkswagon hanging in the rafters. I've read a lot on the forums and everyone raves about the RS20/HD750, but my question is will it be a step up, down, or lateral from the G90.

The LCD sets we have purchased, including high end Sony Bravia to Vizio all look "digital" at some point and handle motion poorly.

I have all the set-up toys to do the job, I just don't want to feel as I have taken a step down.

Comments, please.

John

John -

You might consider posting this in the general RS20 thread since this isn't a calibration issue.
You might also get more "bites" there as well.

Good luck.

Mike
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post #238 of 1634 Old 05-01-2009, 01:28 PM
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Even though this is the wrong thread to have posted that in, the G90 is still imo the king of projectors when all things are considered and we are just talking performance. I love my HD750 but it isn't as good as my buddies G90.
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post #239 of 1634 Old 05-01-2009, 02:04 PM
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Quote:
Originally Posted by JeffY View Post

It must be a projector variance, your blue settings are way too dark and a bit purple (especially dark blues) on my projector.

Guys,
For what it is worth---I have loaded in Manni's third attempt and Jeffy's new settings and compared them as objectively as I can by eye, to the THX CMS setup (I have no metering capability). I want to report my findings and have a question on the logic and validity of my conclusion that some of these settings look like they may be transferable to my projector with excellent results.

What I find is that that low saturation/lighter looking blues on Jeffy's settings match THX almost exactly, but Manni's are very clearly darker/or more saturated in appearance. Using THX as a reference, this is the only clear subjective difference I can see viewing many real world reference Video and Film segments I use for such judgments .

I also have been using 2 other objective ways to judge the color accuracy which may -or may not be valid:
1. First it seems to me that if the Color settings in the CMS are calibrated properly that the old standby filter method of setting the Color and Tint controls using the VDE BD disk should ideally yield Tint and Color control settings of exactly zero. Deviations here would indicate that the color CMS performance is not spot on (I am making the assumption that the Color Decoder in the RS20 is accurate). (I should note here that I found the THX mode unexpectedly required a color setting of 5 to satisfy this criteria. All comparisons below were made with this THX setting).

2. Secondly, after the Color and tint controls have been properly set, if Color filters are used with the VDE basics BD test disk to view the color bar pattern for testing color decoder errors.. then the R,G and B color decoders should look perfect (example... all of the primary and secondary colors and white viewed through the red filter should have the same red intensity).

Now I realize that many other criteria for excellent performance of the CMS setting exist ... but it seems to me that these 2 criteria above represent necessary but not sufficient conditions for a properly functioning CMS.
That said I found all of the CMS work around settings developed on the original Calibration site did not meet the 2 criteria above (even though they produced very reasonable -good looking images and helped us get through the "broken CMS era.) Since the CMS was defective this could be expected.

But now with the new version of the CMS firmware - and with simply copying in settings arrived at by Calibrations performed on projectors other than mine -I find that the CMS performance now unexpectedly comes extremely close to satisfying the above two "necessary" criteria.

Specifically, I found that Jeffy's new CMS settings produce almost perfect Color decoding while simultaneously satisfying the Color /Tint controls setting of 0. In other words Jeffy's settings seem to satisfy both of my Necessary conditions (and as discussed above - the less saturated blues match the THX blues perfectly).

I found Manni's 3rd attemt produces near perfect Color decoder behavior- but only if I set the Color control at +10 (Tint is fine at 0). And as mentioned above less saturated blues do not match the THX blues) So, at least on my projector, this case comes close to satisfying the 2 necessary conditions.

So my question is this.. do these results indicate a high probability that Jeffy's settings installed on my projector, results in a reasonable CMS setup?
If checked with, lets say, Jeffy's Calibration meter and software, would he end up with a pretty good Calibration report..or is it simply not the case that the 2 criteria I have set out are sufficient to allow drawing such a conclusion?

Thoughts on this would be appreciated.
And many thanks to Manni and Jeffy for contribution of their new settings.

KT
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post #240 of 1634 Old 05-01-2009, 02:18 PM
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Quote:
Originally Posted by KTTV Images View Post

I also have been using 2 other objective ways to judge the color accuracy which may -or may not be valid:
1. First it seems to me that if the Color settings in the CMS are calibrated properly that the old standby filter method of setting the Color and Tint controls using the VDE BD disk should ideally yield Tint and Color control settings of exactly zero. Deviations here would indicate that the color CMS performance is not spot on (I am making the assumption that the Color Decoder in the RS20 is accurate). (I should note here that I found the THX mode unexpectedly required a color setting of 5 to satisfy this criteria. All comparisons below were made with this THX setting).

See Greg R's comments below about using filters with pseudo primaries.

http://www.avsforum.com/avs-vb/showp...&postcount=206

In such cases, filters can yield grossly inaccurate recommendations. Not a good idea.

Tom Huffman
ChromaPure Software/AccuPel Video Signal Generators
ISF/THX Calibrations
Springfield, MO

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