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Official JVC RS20 / HD750 Calibration and CMS thread - Page 10

post #271 of 1782
This is totally going in the wrong direction. Here is a hint: Start from -25 saturation and do the proper CMS adjustment, that will give you a much better result. Later you have to compensate for the saturation loss in the source. I don't know why JVC did this crazy design, but this was the only approach I could get good results, howver the results are much better than with the THX settings.

No purple look or whatsoever.

The HD750/RS20 is a major step forward, don't get confused.
post #272 of 1782
Quote:
Originally Posted by Lawguy View Post

All right. Bad news confirmed.

Using Tom's patterns (which, by the way measure differently than the AVS patterns (which is right?)) I have confirmed that things go decidely pear shaped when moving from 100% colors to 75% or under.

It is not as if the results track a little bit off. They are WAY off with some of the colors.

This is very disappointing.

I also confirm that the THX settings do not realy vary from 100% to 75%. The THX settings generally are pretty close, btw.

I recommend using the THX settings, even though you can't adjust gamma or anything else for that matter.

1) Is this with you calibrating the CMS at 100% or at 75%? Which ever way it is, have you tried it the other way? For instance, say you calibrated at 100%. Perhaps if you calibrate at 75%, then maybe things will hold up much better when going up to 100% and down from 75%.

2) Have you displayed 50% red (for example), and then a 75% and 100% red sequentially, and when doing so can you see it shift in color? If things are ok then it should just get brighter but not actually shift in tone. Can you try this and let us know?

3) To me THX it is not an acceptable workaround for a number of big reasons. A big draw of the RS20 to me is the CMS controls, and from

4) Can you display a color saturation scales pattern? Do the colors look consistent?

5) Can you please post some CIE charts that show a few examples of the poor readings?

6) I am not totally discouraged by these reports. I did have a few moments to dial in the CMS and then do some very brief testing. In this brief testing I did not notice anything significantly wrong. If I'm reading some of this data correctly, then at some % levels red would look magenta (as just one example) - that's going to be hard to miss and I didn't see this type of issue. But as I said it was very brief and limited testing. The only thing that really drew attention to itself post-CMS calibration was that the overall picture level seemed to get brighter (almost like the gamma had gone down). But I didn't have time to go back and measure everything to see what was going on.
post #273 of 1782
I can confirm what Lawguy found about 100IRE vs 75IRE measurements, this is exactly why I badly want the THX mode to be calibratable, and I still don't understand how THX can charge calibrators for calibration education, and at the same time allow THX certified products that are non-calibratable in THX mode.

BTW, I think a lot of people won't quite get the difference between a 25/50/75/100% saturation and a 25/50/75/100% brightness RGBCMY measurement... Perhaps someone can explain better than me what the difference is... And I believe that one could be correct while the other is off. Both should be correct for absolutely bullet-proof accurate color. I'm not sure any display in the world actually achieves that though, even within studios, so while it never hurts to know the goal, we shouldn't start bashing displays that don't achieve that too much.

When I get back to my own PC, I'll look for the measurements from the THX mode. I believe I god dE94 numbers of less than 2 for both RGBCMY and greyscale, in THX mode off-screen from a ST130. The fact that the CMS isn't as good as it should be, does not change my view that the RS20 is a significant upgrade from an RS2.
post #274 of 1782
Otto, can you try my approach starting with something like -25 saturation and calibrate from there (including later compensation for the saturation loss by increasing the saturation level of the source)?!
post #275 of 1782
Quote:
Originally Posted by clehner View Post

This is totally going in the wrong direction. Here is a hint: Start from -25 saturation and do the proper CMS adjustment, that will give you a much better result. Later you have to compensate for the saturation loss in the source. I don't know why JVC did this crazy design, but this was the only approach I could get good results, howver the results are much better than with the THX settings.

No purple look or whatsoever.

The HD750/RS20 is a major step forward, don't get confused.

From what I remember, starting with a large negative number for overall saturation (Color control) makes it so that you cannot raise brightness for Blue high enough with the CMS controls (leaves you way short). I first tried with -30 or -25 (can't recall) and that's what happened, so I had to use a higher value for Color (I think it was -17).
post #276 of 1782
Quote:
Originally Posted by Otto J View Post

I can confirm what Lawguy found about 100IRE vs 75IRE measurements, this is exactly why I badly want the THX mode to be calibratable, and I still don't understand how THX can charge calibrators for calibration education, and at the same time allow THX certified products that are non-calibratable in THX mode.

BTW, I think a lot of people won't quite get the difference between a 25/50/75/100% saturation and a 25/50/75/100% brightness RGBCMY measurement... Perhaps someone can explain better than me what the difference is... And I believe that one could be correct while the other is off. Both should be correct for absolutely bullet-proof accurate color. I'm not sure any display in the world actually achieves that though, even within studios, so while it never hurts to know the goal, we shouldn't start bashing displays that don't achieve that too much.

When I get back to my own PC, I'll look for the measurements from the THX mode. I believe I god dE94 numbers of less than 2 for both RGBCMY and greyscale, in THX mode off-screen from a ST130. The fact that the CMS isn't as good as it should be, does not change my view that the RS20 is a significant upgrade from an RS2.

This raises an interesting question. Are you guys reporting these measurements based on patterns that use lower *saturation* or patterns that use a lower % level (i.e. 75% brightness vs 100%)?
post #277 of 1782
Quote:
Originally Posted by lovingdvd View Post

cannot raise brightness for Blue high enough with the CMS controls (leaves you way short).

Hm, Blue never was a problem for me, only Red and esp. Green. Where did you end up with Blue? Oversaturated no matter what?

@Otto J: The difference between saturation and brightness can probably best explained using the three dimension of the CIE chart.
post #278 of 1782
Quote:
Originally Posted by clehner View Post

The HD750/RS20 is a major step forward, don't get confused.

I'm perfectly satisfied with the black level, sharpness, and uniformity of my RS2 which was a significant step forward from my RS1 plus my RS2 had not even a hint of bright corners. The results from the only properly performed white level matched comparison between the the RS2 and the RS20 are not consistent with your impressions the RS20 is a major step forward. If it were that would be great but I primarily want a CMS and what has been recently reported is not the type of info which is pushing off the fence.
post #279 of 1782
Quote:
Originally Posted by clehner View Post

Hm, Blue never was a problem for me, only Red and esp. Green. Where did you end up with Blue? Oversaturated no matter what?

@Otto J: The difference between saturation and brightness can probably best explained using the three dimension of the CIE chart.

I had blue slightly oversaturated, on purpose. I could have closed it to the Rec 709 point (or at least very close to it). With Color set to low I ran out of brightness and it was like 50% off there. But with a higher Color control setting I had enough brightness in blue to get very close to its proper %.
post #280 of 1782
Quote:
Originally Posted by Lawguy View Post

Using Tom's patterns (which, by the way measure differently than the AVS patterns (which is right?)) I have confirmed that things go decidely pear shaped when moving from 100% colors to 75% or under.

I did these very fast (30min.) in Paint Shop Pro. If there are differences, I would trust AVS. The differences shouldn't be large. I can test mine later against the Accupel signal generator.
post #281 of 1782
Quote:
Originally Posted by Otto J View Post

I can confirm what Lawguy found about 100IRE vs 75IRE measurements, this is exactly why I badly want the THX mode to be calibratable, and I still don't understand how THX can charge calibrators for calibration education, and at the same time allow THX certified products that are non-calibratable in THX mode.

BTW, I think a lot of people won't quite get the difference between a 25/50/75/100% saturation and a 25/50/75/100% brightness RGBCMY measurement... Perhaps someone can explain better than me what the difference is.

I don't think that here's anything inherent to THX certification that precludes calibration. This is just the way JVC decided to implement it. For example, you can perform a service menu gray scale calibration of the THX-certified Panasonic TH-50PZ800U plasma in THX mode.

I don't know what 25%,50%,75%,100% "saturation" tests are either. Perhaps this is the same as testing at different levels of stimulus, and just uses (incorrectly) a different word to describe it. The idea, though, is simple enough. It is just like gray scale tracking. If the point of a gray scale calibration is to ensure that white remains a consistent x0.3127, y0.329 from 100% down to 20%, the primary/secondary colors should perform the same. If red measures x0.640, y0.630, Y0.2126 at 75% stimulus, it should stay that way as the level of stimulus goes up and down.

Displays seem fairly linear in this respect in their native mode, but only begin to exhibit non-linear behavior when the gamut is digitally manipulated by a CMS. The Radiance CMS does fairly well in this respect. The RS20's CMS, at least at this stage of development, apparently doesn't.

It may be that it is not the RS20's CMS per se that causes this problem. The problem may arise as a result of having to lower the main Color control in conjunction with the CMS controls to get otherwise decent results. Of course, the reason you have to do this in the first place is that the CMS has a limited range of operation. However, the controls also appear to have unwanted interactive effects, so it is hard to say what exactly is causing this problem.
post #282 of 1782
Lawguy - did you use the AVS HD 709 pattern disc Saturation Windows to measure those xy coords you reported?

If so I think that explains the values appearing to be off, when in fact that may be normal for those patterns.

For instance, those patterns reduce saturation as you move from 100% to 0%. The % I believe Tom wanted measured was stimulus % (to impact Y only). I believe that with Y at 100% Tom wanted to see what the xyY looked like with Y at 75% and 50% and so forth.

But with those test patterns the actual *saturation* used in the patterns is progressively lower, so of course that is going to move the measured color point toward white as the saturation % moves down.

I think what you need for Tom's measurement he requested is a color scales pattern, but not sure. Then again Tom sent patterns that were representative of what he wanted measured and although you measured slightly different values than on AVS HD 709 disc they sounded pretty close so who knows.
post #283 of 1782
One more thing that I will try is to calibrate at the 75% level and see how that tracks.

I ordered a copy of the Service Manual as well. Hopefully access to the Service Menu will give us access to some useful adjustments.
post #284 of 1782
Quote:
Originally Posted by lovingdvd View Post

Lawguy - did you use the AVS HD 709 pattern disc Saturation Windows to measure those xy coords you reported?

If so I think that explains the values appearing to be off, when in fact that may be normal for those patterns.

For instance, those patterns reduce saturation as you move from 100% to 0%. The % I believe Tom wanted measured was stimulus % (to impact Y only). I believe that with Y at 100% Tom wanted to see what the xyY looked like with Y at 75% and 50% and so forth.

But with those test patterns the actual *saturation* used in the patterns is progressively lower, so of course that is going to move the measured color point toward white as the saturation % moves down.

I think what you need for Tom's measurement he requested is a color scales pattern, but not sure. Then again Tom sent patterns that were representative of what he wanted measured and although you measured slightly different values than on AVS HD 709 disc they sounded pretty close so who knows.

Yes. I misunderstood Tom initially. I subsequently used his patterns and that is where I found the huge differences, which I confirmed with the AVS patterns.
post #285 of 1782
Quote:
Originally Posted by lovingdvd View Post

Lawguy - did you use the AVS HD 709 pattern disc Saturation Windows to measure those xy coords you reported?

If so I think that explains the values appearing to be off, when in fact that may be normal for those patterns.

For instance, those patterns reduce saturation as you move from 100% to 0%. The % I believe Tom wanted measured was stimulus % (to impact Y only). I believe that with Y at 100% Tom wanted to see what the xyY looked like with Y at 75% and 50% and so forth.

If you look at my files,THX values are close to gamut for both 100% and 75%.
User1 calibrated doesn't.
I suppose Tom is right, the problem for me it is the CMS in conjuction with lowering Color setting ( I set it to -18).
Maybe we must find another solution.
I will investigate in the next days.
The positive thing is THX presect is quite good both at 100% and 75% so the harware and firmware of RS20 allows, with the right settings, to reach nice results.
We need only to find the right workaround..
post #286 of 1782
I have run some measurements with HCFR at 0%, 25%, 50%, 75% and 100% on the THX preset and on my last (untouched since my last post) user1 settings... It's quite ugly!

I attach the HCFR files if you want to look at all the data (too much to post and HCFR is free and very easy to install) and I post a few screenshots to give you a taste of the results.

My PJ has 65H on the lamp anf the greyscale for the THX preset is still completely off. The gamut is nice, and the colors are much more coherent over different saturations than my preset.

Here you go... THX first, user settings to follow...
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THX 65H.zip 4.8115234375k . file
post #287 of 1782
User settings...

The red has shifted a bit towards oversaturation (lamp aging?).

They still look better than THX (to my eyes) probably because of the better greyscale.

It may justify an attempt between -15 to -25 for the color settings, but I'm going to wait until I reach 100 hours...

 

Manni 65H.zip 4.8251953125k . file
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post #288 of 1782
Quote:
Originally Posted by Manni01 View Post

User settings...

The red has shifted a bit towards oversaturation (lamp aging?).

They still look better than THX (to my eyes) probably because of the better greyscale.

It may justify an attempt between -15 to -25 for the color settings, but I'm going to wait until I reach 100 hours...

Manni01 - thank you. This is very helpful in clearly showing the issue.

When you calibrated your CMS did you use 75% of 100% patterns? Have you tried doing the other? Perhaps that will come out with a better result.

Also if you have a chance can you post the default OOTB gamut with the 0-100% saturation points as you did with User1 and THX? I know the colors are oversaturated OOTB but I am very curious if these at least track.

From the gamut it seems there could be some small visible color issues particularly around 75% blue, but may be not much discernible elsewhere.

So it seems there is yet another variable to balance out when doing the CMS work here... IOW one will now have to balance not only the gamut but perhaps sacrificing the Rec 709 points a bit for a better tracking saturation from 0 - 100%.

Fortunately I prefer an oversaturated gamut. So in my case the changes I need to make are much less than what is needed to reach Rec 709. So hopefully this will keep the saturation tracking issues to a minimum (due to smaller changes needed to the controls to begin with).
post #289 of 1782
Quote:
Originally Posted by lovingdvd View Post

Manni01 - thank you. This is very helpful in clearly showing the issue.

When you calibrated your CMS did you use 75% of 100% patterns? Have you tried doing the other? Perhaps that will come out with a better result.

Also if you have a chance can you post the default OOTB gamut with the 0-100% saturation points as you did with User1 and THX? I know the colors are oversaturated OOTB but I am very curious if these at least track.

From the gamut it seems there could be some small visible color issues particularly around 75% blue, but may be not much discernible elsewhere.

So it seems there is yet another variable to balance out when doing the CMS work here... IOW one will now have to balance not only the gamut but perhaps sacrificing the Rec 709 points a bit for a better tracking saturation from 0 - 100%.

Fortunately I prefer an oversaturated gamut. So in my case the changes I need to make are much less than what is needed to reach Rec 709. So hopefully this will keep the saturation tracking issues to a minimum (due to smaller changes needed to the controls to begin with).

Happy to help, LovingDVD! I'd be happy to post the OOTB measurements, but my 750 is far from its OOTB state now, so you would have to tell me which preset/color temp/gamma preset you'd like me to select (I assume with a color setting back to 0). I can't remember the original settings for these...

I did calibrate using the 100% windows, and I would be tempted to experiment with 75% to see if the saturation is tracking better, unfortunately I don't know how to tell HCFR I'm using 75% patterns, and I don't see how it can display the gamut adjusted to 75% if it doesn't know (I need the CIE diagram to get close enough and then I fine-tune looking at the coordinates, but I'm not going to try to calibrate this thing looking at numbers only!). Is it diferent in Calman? What are you using?

Regarding oversaturated primaries, I don't have a problem with this within reason (ie not in the OOTB state!), and am less sensitive to oversaturated green than reds. Please post your oversaturated gamut, so I can heve a look at what you find "acceptable" or even "preferable".

Are you experimenting with Jason's range (-15 / -22), which has been suggested by a few other users as well? I'd like to see some data from this color range before I embark on my 5th attempt when I reach 100 hours...
post #290 of 1782
It occurs to me that JVC made a huge design mistake. All they had to do was ensure that the THX mode had a reasonably accurate grayscale OOTB or allowed it to be calibrated via the user menu. If they had, they could have dispensed with the CMS, then for the great majority of users all these problems would have been avoided. The THX gamut, while not perfect, is reasonably good, something I cannot say for the grayscale, which doesn't even meet the relatively low standard of presets offered by competing products.
post #291 of 1782
I wonder if anyone has done measurements enough to answer the following question: at min throw (i.e., max zoom), what is the iris setting on Normal (i.e., low) lamp mode that gives the same brightness (# of lumens) as High lamp and Iris = -15.

I'm guessing a setting of iris ~ -8, but it would be helpful if someone knew more precisely. TIA
post #292 of 1782
Quote:
Originally Posted by TomHuffman View Post

It occurs to me that JVC made a huge design mistake.

Sorry, that's too strong. Of course things could be easier to handle. However, with a little effort you can reach the same color precision as the built in THX settings (which aren't perfect either, but REC709 presets with other products aren't so perfect either). All you have to find is the tricky way to use the CMS.

OTOH: If you don't want to deal with all that, use the THX mode in high lamp mode, which is a good basis for everything and also has reasonable good grey scale tracking.

BTW: Thanks Tom for providing us with the patterns which I used to test the THX settings and confirmed that my own settings were quite close (but I had to fiddle around quite a while to achieve that).
post #293 of 1782
Quote:
Originally Posted by Manni01 View Post

Are you experimenting with Jason's range (-15 / -22), which has been suggested by a few other users as well? I'd like to see some data from this color range before I embark on my 5th attempt when I reach 100 hours...

My calibration was made at -18..
post #294 of 1782
Quote:
Originally Posted by clehner View Post

Sorry, that's too strong. Of course things could be easier to handle. However, with a little effort you can reach the same color precision as the built in THX settings (which aren't perfect either, but REC709 presets with other products aren't so perfect either). All you have to find is the tricky way to use the CMS.

OTOH: If you don't want to deal with all that, use the THX mode in high lamp mode, which is a good basis for everything and also has reasonable good grey scale tracking.

BTW: Thanks Tom for providing us with the patterns which I used to test the THX settings and confirmed that my own settings were quite close (but I had to fiddle around quite a while to achieve that).

The problem with the CMS is that the results are only good for one stimulus level. The CMS is useless unless it gives good results at all levels. I don't think Tom's language was too strong.

The crazy thing is that the RS20 has the best projected image that I have ever seen but I feel very let down about the implementation of the CMS.
post #295 of 1782
Quote:
Originally Posted by Lawguy View Post

The CMS is useless unless it gives good results at all levels.

Well, just give yourself some more time, you should be able to get to the same result as the THX colors provide (as I said, the THX settings aren't that perfect either). However I have reached a point where I am satisfied with the result. As I have said, I tried the patterns provided by TOM with the THX settings as well with the ones created with the CMS and they are close.

Quote:
Originally Posted by Lawguy View Post

The crazy thing is that the RS20 has the best projected image that I have ever seen ...

You see. That's what you should emphasize more.

I don't think any other product in that price range has absolutely perfect colors if you put it to the same tests as the HD750/RS20. Let's put it into persepctive.
post #296 of 1782
A quick OT question, if anyone has a strong feeling one way or the other.

Re the '4:3 Offset' on the Moto remote with Comcast cable: with your RS20, which do you find 'better' (i.e., less bad) for sd cable channels--'OFF', 480i, or 480p? TIA
post #297 of 1782
Quote:
Originally Posted by Manni01 View Post

Happy to help, LovingDVD! I'd be happy to post the OOTB measurements, but my 750 is far from its OOTB state now, so you would have to tell me which preset/color temp/gamma preset you'd like me to select (I assume with a color setting back to 0). I can't remember the original settings for these...

Yes, just put color back to 0, turn CMS off, and use the default 2.2 gamma without any tweaks. You can keep your tweaked grayscale settings for any gain/offset changes you made, and in fact I'd prefer it.

Quote:
I did calibrate using the 100% windows, and I would be tempted to experiment with 75% to see if the saturation is tracking better, unfortunately I don't know how to tell HCFR I'm using 75% patterns, and I don't see how it can display the gamut adjusted to 75% if it doesn't know (I need the CIE diagram to get close enough and then I fine-tune looking at the coordinates, but I'm not going to try to calibrate this thing looking at numbers only!). Is it diferent in Calman? What are you using?

I use HCFR. You do not need to tell HCFR what % you are using. Just redo your Measure Primaries and Secondaries command, and be sure to use the 75% patterns for RGB and White. All the Y data and dE is based off the white reading, so as long as you give it a 75% white pattern when asked to measure white that's all you need to do (along with using 75% for RGBCYM).

Quote:

Regarding oversaturated primaries, I don't have a problem with this within reason (ie not in the OOTB state!), and am less sensitive to oversaturated green than reds. Please post your oversaturated gamut, so I can heve a look at what you find "acceptable" or even "preferable".

Are you experimenting with Jason's range (-15 / -22), which has been suggested by a few other users as well? I'd like to see some data from this color range before I embark on my 5th attempt when I reach 100 hours...

My preferred gamut is attached. Note that all points chosen are intentional. This is a personal preference toward oversaturated colors which purists will not care for, but ultimately I find it more interesting so I go by what I like vs. what is technically correct in these cases.

Note that I did not use THX mode because the lack of grayscale tweaks and gamma was a show stopper. I did use it briefly to compare colors to my gamut and it was about as I expected. I used 75% patterns. I used a Color setting of -17. The Y values were pretty much spot on when I was done but I didn't have a chance to really refine it as I would have liked to. Also I would have liked to check the saturation levels as has been discussed lately but did not have a chance. This may have called for a little more careful rebalancing.

I barely had a chance to evaluate this after completing it. But I was pleased with what I saw in the little time I did have to check it out. Skin tones looked nice and noticeably better than the RS1. Color control was at -17. But again I really need a lot more time with it to re-evaluate in the face of all the new data.
LL
post #298 of 1782
Quote:
Originally Posted by clehner View Post

Sorry, that's too strong. Of course things could be easier to handle. However, with a little effort you can reach the same color precision as the built in THX settings (which aren't perfect either, but REC709 presets with other products aren't so perfect either). All you have to find is the tricky way to use the CMS.

I am at something of a disadvantage here compared to most of you in that I do not actually have a unit to test, but my understanding of the more recent posts is that the CMS settings allow you to get good results only at a single level of stimulus, whereas the THX preset performance remains linear throughout the color scale (coining a phrase), as it should.
post #299 of 1782
Now that people are starting to see things more clearly, I feel it more appropriate to post a more candid opinion of this particular aspect of the RS20. I didnt want to come across as slamming a good machine unnecessarily when I posted my initial review.

My own experience of this CMS was that, whilst not difficult to use, it did not appear to be a true, and fully integrated CMS. It doesn't look like one, control like one or act like one.

It feels to me that its simply a "breakout" of the preexisting system into some of its constituent parts. It initially appears more sophisticated and capable than it actually is. JVC missed a home run here. I had expected a root and branch alteration to the color system and its subsequent CMS implementation.

I also feel that there is a hardware limitation to this, and that may be why controls sometimes lack the range and stability they should have. The huge amount of interdependence also speaks to architecture. The fact that external correction is possible lends credence to this.

It may still be a possibility that JVC simply wrote some crap software and that it can be corrected.

For now, and based on previous iterations, I suspect its a hardware issue.

I hope this is taken in the manner intended.
post #300 of 1782
Quote:
Originally Posted by TomHuffman View Post

the CMS settings allow you to get good results only at a single level of stimulus, whereas the THX preset performance remains linear throughout the color scale (coining a phrase), as it should.

No, you can actually get very good results (like the THX settings) on all relevant levels, but it is not so easy to find the sweet spot between lowering the saturation for the right amount and finding suitable settings in the CMS itself. Also, you have to compensate for the lowered saturation in the source. This has been reported before that the interaction of all the parameters is very crucial (and tricky) here (and often goes in a direction you would not expect in the first place). But it's doable.
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