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Official JVC RS20 / HD750 Calibration and CMS thread - Page 22

post #631 of 1782
1/4/09 at 6:57pm
Quote:
Originally Posted by TomHuffman View Post

This is odd, since saturation and gamma were never problem areas in the THX mode to begin with.

I was using the settings manni has provided for his setup, THX mode lacked that "punch" you can get in a user setting which allows gamma control. To be able to control the gamma in THX now has helped alot cause I like the colors there better still though to my eye, I adjusted the saturation to make it even more appealing. I guess that's why we're all different, I go by what I see on the screen & calibrate from there no measuring equipment for me.
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post #632 of 1782
1/4/09 at 6:58pm
Quote:
Originally Posted by pteittinen View Post

Here's what I got of Natural mode OOB, measured with 75% colors (i.e. CalMAN default).

Perhaps you don't know, but can you explain why the header over the xyY values says "Lux"?? Lux is an illuminance measurement which has nothing to do with xy. It might be related to Y, except that you used an X-Rite Chroma 5 meter, which reads luminance only (fL or cd/m2). Just curious.
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post #633 of 1782
1/4/09 at 7:00pm
Quote:
Originally Posted by pmeyer View Post

Just checking: can you adjust all of those gamma/saturation/etc. while watch HDCP protected blu-ray disks? Are you using adjustment software that came with the ATI card, or something else?

Yes you can, I ONLY watch Blu-ray titles, haven't seen a reg dvd for almost 3 years. The software I use is the ATI Catalyst control center.
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post #634 of 1782
1/4/09 at 7:03pm
Quote:
Originally Posted by Chris Dallas View Post

I was using the settings manni has provided for his setup, THX mode lacked that "punch" you can get in a user setting which allows gamma control. To be able to control the gamma in THX now has helped alot cause I like the colors there better still though to my eye, I adjusted the saturation to make it even more appealing. I guess that's why we're all different, I go by what I see on the screen & calibrate from there no measuring equipment for me.

If we have learned anything from this now very long thread it is that there is substantial unit-to-unit variation between RS20's. Simply copying someone else's values to your unit is of extremely limited value.
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post #635 of 1782
1/4/09 at 7:14pm
Chris, try this PC application for better control of gamma & grayscale. More fine grain control than the display drivers.

http://www.avsforum.com/avs-vb/showthread.php?t=1097653
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post #636 of 1782
1/4/09 at 7:16pm
Quote:
Originally Posted by TomHuffman View Post

If we have learned anything from this now very long thread it is that there is substantial unit-to-unit variation between RS20's. Simply copying someone else's values to your unit is of extremely limited value.

I think that applies to grayscale tracking and gain/offset settings in particular. However when it comes to CMS, I am thinking the CMS numbers may be pretty transferable across units. We haven't gathered much data yet, but preliminarily it sounds like the factory defaults for CMS settings such as Natural, Dynamic etc are set the same for all RS20s. Whereas the grayscale in modes like 6500K is not.
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post #637 of 1782
1/4/09 at 7:18pm
Quote:
Originally Posted by TomHuffman View Post

That comes from the inaccurate gray scale tracking. Fix the blue emphasis and this problem would largely, if not entirely, go away.

Tom - in this particular case I think the shift in Cyan toward blue is intentionally set that way by the ironically named "Natural" mode. For instance in the CMS of this mode the hue for Cyan is set to +10. Hue in other modes for other colors is either zero or slightly changed, like -2, etc.
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post #638 of 1782
1/4/09 at 7:22pm
Quote:
Originally Posted by Googer View Post

Ah good catch - I didn't really spend much time looking at the service menu side of these things, but yeah it would appear that the real changes are just that the CMS values for Natural in the service menu aren't all zero'd out to start with as they are for the others. The fact that it may appear that the final applied CMS values are service menu + user menu though (since when I changed Natural hue to -10 it brought cyan back in line with looking more neutral and not so blue) would mean we actually have twice the range as we'd thought though for each control.

It would be great to think this would give us twice the range for the controls. But I think the way it works is that the system likely counter-acts each one. Not sure, just a guess at this point.
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post #639 of 1782
1/4/09 at 11:46pm
Thread Starter 
Quote:
Originally Posted by lovingdvd View Post

What on/off CR are you guys measuring? Please post your measurements, along with your throw (whether you are at short, mid, or long), lamp mode and iris position.

As I reported earlier, on my first RS20 (returned for large convergence error) I measured about 45,000:1 on my Spyder2 meter and 54,000:1 on my CA813. This was with high lamp, mid throw, and iris -15.

With my replacement RS20 I am only getting about 15,000:1 with the same exact setup, so clearly something is wrong. Not only is the bulb a lot dimmer (by about 35%), but the absolute black level is visibly brighter and measures more than 2x brighter compared to my first unit.

I was hoping it was a bad bulb, but even if it is, as Mark pointed out a brighter bulb is just going to increase the black level fairly equally with the increased brightness so CR should remain the same. Perhaps it is a problem with the light engine or power supply in the unit.

At any rate it would be great to hear about the CR you are measuring. Does anyone know what the specification is? I know they say up to 50,000:1, but I am wondering what they expect you to get with the most CR-unfriendly set up (short throw, iris open etc).


Hi Ric, I measured my contrast per your request and found that using the color temp offset adjustments have a profound affect on the black level and therefore contrast of the projector. Initially I measured contrast at THX mode (greyed out 6500 color temp and greyed out normal gamma) at only 17,000:1. Thinking that maybe there was a lumen problem I selected user1 mode, selected custom3 color temp and normal gamma and then proceeded to maximize the white point of custom3 color temp, by keeping the gains at high as possible while still achieving D65. After doing so, I went back and measured a modest increase in white point but the black level inexplicably was reduced to about 1/2 of THX mode, giving me a total of ~44,000:1 contrast!?!

After some thought I realized that I had used the 6500 offset adjustments to quickly get the best starting D65 greyscale throughout the range when I first calibrated the unit so I went in and zeroed out the offset settings (same settings as my custom color temp) and voila suddenly my contrast went to ~44,000:1 in THX mode.

So this is my thinking on how greyscale should be adjusted:
  • Use the gain adjustments to maximize lumens at D65. The RS20 is red limited so this means reducing blue by quite a bit and green a little. Red should NOT be reduced at all.
  • Use the offset adjustment to maximize the black level. I'm not sure yet if it's possible to come close to D65 while preserving the black level (I kind of doubt it) so given the trade off I would personally calibrate for best blacks that may have a slight tint to it rather than have a brighter black that has no tint to it. This could very well come down to a personal tradeoff and how perceptible color is at the minimum black level.
  • Once the gain and offset adjustments are set then adjust the gamma tracking.
  • Once the gamma tracking is set then adjust the greyscale to achieve D65 throughout the range. Care should be taken to minimize the overall brightness changes at the IRE that is being adjusted so the gamma won't be affected as much. This means targeting the color that is furthest from D65 at each IRE point (best to use a display that shows RGB% here).
  • Once all of that has been done then adjust the brightness and contrast settings and then recheck everything.
  • Once the greyscale is done then the primary and secondaries can be adjusted. Unfortunately the CMS process still seems to be TBD.

One last thing I should mention, I noticed a 2-3% RGB shift between iris open and iris -15 positions on my unit. Blue seems to change the most. I had dialed in the greyscale tracking a few times and then gone back and remeasured it a few times and found that it was off significantly each time and blue was usually the biggest culprit. I went back and checked a bunch of stuff incluidng my colorimeter and anything else that could create a bias across IRE ranges. After a lot of experimentation (several evenings actually) I've found the problem (at least on my unit) as a color shift between iris settings.

So before starting to calibrate, a person needs to decide on what iris position they will use most often. I prefer iris -15 so I'm calibrating the greyscale at that position.

Another thing that I'll mention is the RS20 contrast is so good it's close to maxing out the dynamic range of my Chroma-5 colorimeter. For example, when I set it close enough to get good black level readings at iris -15, it can cause problems when reading the white level at iris open. When I move the sensor farther back I can measure the full dynamic range but the black level readings are close to the limit of the sensor. There is a definite sweet spot that's less than 24" or so away.

Anyway I hope this info helps everyone. I haven't spent a lot of time on the CMS yet because the greyscale has been giving me grief so this should save some people some time that have jumped straight to the CMS without spending a lot of time with the greyscale adjustments.
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post #640 of 1782
1/4/09 at 11:59pm
Regarding hope that we could use the CMS in the service menu, I played with this tonight and had the same results as when using CMS in the user menu. Bottom line is that the CMS will not track xyY properly (and can be way off) at different % stimulus levels. We really need a fix for this.
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post #641 of 1782
1/5/09 at 12:06am
I had a chance to measure what increasing Color does when in THX mode. As a test I measured 100% and 75% RGBCYM in THX mode with color set to 0 and then again with color set to 12.

The only different increasing the color control made was that at 75% the Y values for the color increased significantly, while xy remained virtually unchanged. At 100% Y increased just a tiny bit only, because the colors clipped, and like at 75% xy remained unchanged.

From various test patterns even a single click of the color control above 0 and the colors begin to clip at the high end.

Because the CMS will not operate as expected I cannot use it to dial in the colors as desired. So I have to resort to using THX mode and then increasing the color control to about 12 to add the vividness I am after. Its not a great solution given the clipping, but overall looks acceptable and will have to suffice until we can get a CMS fix.
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post #642 of 1782
1/5/09 at 12:19am
Quote:
Originally Posted by Mark Petersen View Post

Hi Ric, I measured my contrast per your request and found that using the color temp offset adjustments have a profound affect on the black level and therefore contrast of the projector. Initially I measured contrast at THX mode (greyed out 6500 color temp and greyed out normal gamma) at only 17,000:1. Thinking that maybe there was a lumen problem I selected user1 mode, selected custom3 color temp and normal gamma and then proceeded to maximize the white point of custom3 color temp, by keeping the gains at high as possible while still achieving D65. After doing so, I went back and measured a modest increase in white point but the black level inexplicably was reduced to about 1/2 of THX mode, giving me a total of ~44,000:1 contrast!?!

After some thought I realized that I had used the 6500 offset adjustments to quickly get the best starting D65 greyscale throughout the range when I first calibrated the unit so I went in and zeroed out the offset settings (same settings as my custom color temp) and voila suddenly my contrast went to ~44,000:1 in THX mode.

So this is my thinking on how greyscale should be adjusted:
  • Use the gain adjustments to maximize lumens at D65. The RS20 is red limited so this means reducing blue by quite a bit and green a little. Red should NOT be reduced at all.
  • Use the offset adjustment to maximize the black level. I'm not sure yet if it's possible to come close to D65 while preserving the black level (I kind of doubt it) so given the trade off I would personally calibrate for best blacks that may have a slight tint to it rather than have a brighter black that has no tint to it. This could very well come down to a personal tradeoff and how perceptible color is at the minimum black level.
  • Once the gain and offset adjustments are set then adjust the gamma tracking.
  • Once the gamma tracking is set then adjust the greyscale to achieve D65 throughout the range. Care should be taken to minimize the overall brightness changes at the IRE that is being adjusted so the gamma won't be affected as much. This means targeting the color that is furthest from D65 at each IRE point (best to use a display that shows RGB% here).
  • Once all of that has been done then adjust the brightness and contrast settings and then recheck everything.
  • Once the greyscale is done then the primary and secondaries can be adjusted. Unfortunately the CMS process still seems to be TBD.

One last thing I should mention, I noticed a 2-3% RGB shift between iris open and iris -15 positions on my unit. Blue seems to change the most. I had dialed in the greyscale tracking a few times and then gone back and remeasured it a few times and found that it was off significantly each time and blue was usually the biggest culprit. I went back and checked a bunch of stuff incluidng my colorimeter and anything else that could create a bias across IRE ranges. After a lot of experimentation (several evenings actually) I've found the problem (at least on my unit) as a color shift between iris settings.

So before starting to calibrate, a person needs to decide on what iris position they will use most often. I prefer iris -15 so I'm calibrating the greyscale at that position.

Another thing that I'll mention is the RS20 contrast is so good it's close to maxing out the dynamic range of my Chroma-5 colorimeter. For example, when I set it close enough to get good black level readings at iris -15, it can cause problems when reading the white level at iris open. When I move the sensor farther back I can measure the full dynamic range but the black level readings are close to the limit of the sensor. There is a definite sweet spot that's less than 24" or so away.

Anyway I hope this info helps everyone. I haven't spent a lot of time on the CMS yet because the greyscale has been giving me grief so this should save some people some time that have jumped straight to the CMS without spending a lot of time with the greyscale adjustments.

Thanks Mark, this is very useful. I did notice that some factors seem to affect the black levels of the 750 and this is a good explananation. Can you see the difference visually (ie when looking at the screen in the dark with no picture) before and after greyscale adjustment? I still find my black levels quite high visually when no picture is displayed (less noticeable when a picture is displayed) and am hoping to be able to lower them with your tips. Still waiting to get a light meter though, as my i1 is not up to the job.
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post #643 of 1782
1/5/09 at 12:35am
Thread Starter 
Quote:
Originally Posted by Manni01 View Post

Thanks Mark, this is very useful. I did notice that some factors seem to affect the black levels of the 750 and this is a good explananation. Can you see the difference visually (ie when looking at the screen in the dark with no picture) before and after greyscale adjustment? I still find my black levels quite high visually when no picture is displayed (less noticeable when a picture is displayed) and am hoping to be able to lower them with your tips. Still waiting to get a light meter though, as my i1 is not up to the job.

Now that I know what to look for I think it should be easy enough to spot. Shadow puppets seem to be clearly visible even with the iris @ -15. I wish I had measured the contrast before and after tweaking the greyscale and CMS as this would have clued me in earlier, but live and learn.

Fwiw getting rid of the brown tint in THX mode makes a huge improvement as I'm sure you've already found out by now. Overall, I find the colors to be a huge improvement over the RS-1 even if the CMS (so far) isn't working that great for us.

I still have a lot of contrast measurements to do. I have an older model PR photometer and a CA813 that I'll use and compare with the C-5.
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post #644 of 1782
1/5/09 at 1:18am
Thread Starter 
Quote:
Originally Posted by Manni01 View Post

Can you see the difference visually (ie when looking at the screen in the dark with no picture) before and after greyscale adjustment?

Fwiw, I tried an experiment of displaying full field off and then adjusting the color temp offset settings while viewing the results. When changing green by just +1 from 0, I could clearly see the black level change even with all of the luminance coming off of the screen from the OSD menu. Red and blue are a little harder to see but even still going to +2 on those are easy to see. So overall, I couldn't see a person raising these settings above 0 unless they view color accuracy in blacks above all else (including black levels and contrast).
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post #645 of 1782
1/5/09 at 1:19am
Quote:
Originally Posted by lovingdvd View Post

Regarding hope that we could use the CMS in the service menu, I played with this tonight and had the same results as when using CMS in the user menu. Bottom line is that the CMS will not track xyY properly (and can be way off) at different % stimulus levels. We really need a fix for this.

It's getting quite frustrating for me not to be able to try any of these new leads, but just to be sure this one is a dead end before we discard it, did you try the following:

- Check what is the saturation level on green in natural preset in normal menu mode (as I understand the CMS is accessible in this preset). If if doesn't show 0, then this is probably not going to work, but if t does shows 0, can you try the following:
- Go to service menu, natural mode. Reduce saturation to -30 on green.
- Measure the gamut
- Go to normal mode, natural mode. Reduce saturation to -30 on green.
- Measure the gamut.

If the two measured gamuts are the same (and green is still oversaturated), then this is probably a dead end.

Otherwise, it means that the service menu adjustments are added to the normal menu adjustments, and there may be hope!
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post #646 of 1782
1/5/09 at 1:29am
Quote:
Originally Posted by Mark Petersen View Post

Fwiw, I tried an experiment of displaying full field off and then adjusting the color temp offset settings while viewing the results. When changing green by just +1 from 0, I could clearly see the black level change even with all of the luminance coming off of the screen from the OSD menu. Red and blue are a little harder to see but even still going to +2 on those are easy to see. So overall, I couldn't see a person raising these settings above 0 unless they view color accuracy in blacks above all else (including black levels and contrast).

Thanks very much for this Mark. Another reason for a person raising these settings above zero is... ignorance! That's what I did when I worked on my greyscale as I was trying to minimise the amount of gamma adjustment (given how impredictable I find the gamma controls). So as an attempt to flatten the greyscale as much as possible before playing with gamma settings, I ended up with a red offset at +4 and a blue offset at +1...

There may be a unit to unit variation at play here (as the ootb THX greyscale is more green than brown on my unit), but still it's really useful to know that moving the offset parameters has such an impact on contrast, because I do not value color accuracy to the extent of being ready to accept knowingly such a compromise on contrast. I will definitely keep this in mind for my next attempt! Thanks again.
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post #647 of 1782
1/5/09 at 1:40am
The offsets might still be useful for adjusting gamma a bit since you can't otherwise do it for THX. Setting red green and blue offsets to -1 might get you closer to a 2.3 gamma curve, worth trying if that is what you want.
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post #648 of 1782
1/5/09 at 1:45am
Quote:
Originally Posted by JeffY View Post

The offsets might still be useful for adjusting gamma a bit since you can't otherwise do it for THX. Setting red green and blue offsets to -1 might get you closer to a 2.3 gamma curve, worth trying if that is what you want.

Thanks Jeff, I'll try that (I guess it can only help contrast!). I have found that a gamma of 2.3 is the best compromise for me between absolute black level and black details, and am a bit concerned that there are no gamma adjustment in "tweaked" THX.
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post #649 of 1782
1/5/09 at 1:55am
Quote:
Originally Posted by TomHuffman View Post

Perhaps you don't know, but can you explain why the header over the xyY values says "Lux"?? Lux is an illuminance measurement which has nothing to do with xy. It might be related to Y, except that you used an X-Rite Chroma 5 meter, which reads luminance only (fL or cd/m2). Just curious.

No idea. That's something we should ask the guys at CalMAN.
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post #650 of 1782
1/5/09 at 1:59am
Quote:
Originally Posted by lovingdvd View Post

Thanks for posting this. This is very helpful. (BTW I assume by "with 75% colors" you mean 75% stimulus and not 75% saturation).

75% stimulus, yes.

Quote:


If you have a chance, can you post the same thing except measured with 100%?

I haven't measured Natural at 100% levels, but may have time to do that later tonight, we'll see.

Quote:


Also I'm not sure if I am interpreting your Y measurements correctly. In the chart it shows "5 689,98..." for white and "2 697,08" for green. Is this the equivalent of 5,689.98 and 2,697.08?

Yup. Finns separate thousands with a space, not a comma, and decimals with a comma instead of a full stop.
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post #651 of 1782
1/5/09 at 2:13am
Quote:
Originally Posted by Chris Dallas View Post

Yes you can, I ONLY watch Blu-ray titles, haven't seen a reg dvd for almost 3 years. The software I use is the ATI Catalyst control center.

This will explain why you are happy with your HTPC... You can set the refresh rate to HDTV1080P24 and forget about it (as long as you don't play games).

Despite the fact that all my DVDs (500+) are backed up up on a NAS and directly accessible using the excellent MyMovies (Media Centre plug-in), I gave up on my HTPC because I didn't find any satisfying way to automatically adjust the vertical refresh rate when switching from watching a BD to watching a PAL DVD to watching an NTSC DVD to playing games...

So now my HTPC is setup for playing games, and I watch BD from my BD player and DVDs from my DVD player, which also allows me to have a separate calibration for each input (RGB/REC709/REC601).

I should explore AnyDVD's ability to adjut refresh rates automatically (I recently found out about this), but if anyone knows of an elegant, automatic solution, please let me know!

To go back to topic (sorry), I would also recommend the software deanbob suggested to adjust gamma, or this one http://www.avsforum.com/avs-vb/showt...ighlight=gamma if it works better with your ATI card.
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post #652 of 1782
1/5/09 at 2:49am
1 Realize that unit to unit variation is part of lcos. What makes lcos possible is the advanced schemes used to handle panel non uniformities. The fact that a calibration from one machine does not work for another machine is to be expected.

2 Inexperienced calibration will not maximize dynamic range. A lower on/off with a user caiibration might not be a sign of a defective unit. It could be that you as a user is not getting all the dynamic range that is possible.

I think you guys should be on the JVC payroll for product testing if you work without teliing the public of any problems. I hope JVC will read this and fix a few things such as the CMS and then with a CMS and the user gamma imagine what a picture you could get!
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post #653 of 1782
1/5/09 at 4:19am
Quote:
Originally Posted by Ohlson View Post

I think you guys should be on the JVC payroll for product testing if you work without teliing the public of any problems. I hope JVC will read this and fix a few things such as the CMS and then with a CMS and the user gamma imagine what a picture you could get!

Based on his preproduction sample, Ekkehart from Cine4Home stated that he raised the issues with the CMS to JVC. He later stated that the issues would not be corrected by the time of release.

Unfortunately, the many hours that me and others have put on our lamps and projectors have been entirely unproductive because we have made no progress. Rather, we are just at the point where our diagnosis is clear: the CMS controls don't work as they should.

The thing that is left to wonder about is how on Earth were the THX gamut settings arrived at? I would wager money that they cannot be replicated in the CMS.
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post #654 of 1782
1/5/09 at 4:45am
Quote:
Originally Posted by Manni01 View Post

on my HTPC because I didn't find any satisfying way to automatically adjust the vertical refresh rate when switching from watching a BD to watching a PAL DVD to watching an NTSC DVD...

On the contrary: Playing everything with 1080p/24Hz will allow you to hear the PAL-DVD sound with the correct pitch (reclock being present).

You actually mentioned the one most important reason WHY an HTPC makes sense for PAL.

If you want to know more cf.
http://forum.slysoft.com/showthread.php?t=19931

Apologies for the off topic post.
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post #655 of 1782
1/5/09 at 4:58am
Quote:
Originally Posted by clehner View Post

On the contrary: Playing everything with 1080p/24Hz will allow you to hear the PAL-DVD sound with the correct pitch (reclock being present).

You actually mentioned the one most important reason WHY an HTPC makes sense for PAL.

If you want to know more cf.
http://forum.slysoft.com/showthread.php?t=19931

Apologies for the off topic post.

Thanks, I'll try this and will PM you if I still get what I used to get with 1080P24 (without reclock) and DVDs (either PAL or NTSC): unwatchable movies because of incorrect frame rate/refresh (lots of stutter/judder on any moving shot, ie pano). BD were fine though!

By the way, this is NOT fully OT because an HTPC may be the only way around the flawed CMS of the 750...

EDIT: I forgot the other reason why I left my HTPC for serious movie watching: HD Audio...
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post #656 of 1782
1/5/09 at 5:34am
Quote:
Originally Posted by clehner View Post

On the contrary: Playing everything with 1080p/24Hz will allow you to hear the PAL-DVD sound with the correct pitch (reclock being present).

You actually mentioned the one most important reason WHY an HTPC makes sense for PAL.

If you want to know more cf.
http://forum.slysoft.com/showthread.php?t=19931

Apologies for the off topic post.

Careful many films are already pitch corrected.
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post #657 of 1782
1/5/09 at 5:46am
Quote:
Originally Posted by JeffY View Post

Careful many films are already pitch corrected.

Believe me: Almost none! I have done research.

OTOH: There are even some Blu Ray titles released in Europe which have been mastered from 50Hz and have wrong pitch. Horrible. They only way to cope with this is using an HTPC.

But this is really off topic now. If you are interested check the slysoft forum.
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post #658 of 1782
1/5/09 at 6:27am
Quote:
Originally Posted by Manni01 View Post

It's getting quite frustrating for me not to be able to try any of these new leads, but just to be sure this one is a dead end before we discard it, did you try the following:

- Check what is the saturation level on green in natural preset in normal menu mode (as I understand the CMS is accessible in this preset). If if doesn't show 0, then this is probably not going to work, but if t does shows 0, can you try the following:
- Go to service menu, natural mode. Reduce saturation to -30 on green.
- Measure the gamut
- Go to normal mode, natural mode. Reduce saturation to -30 on green.
- Measure the gamut.

If the two measured gamuts are the same (and green is still oversaturated), then this is probably a dead end.

Otherwise, it means that the service menu adjustments are added to the normal menu adjustments, and there may be hope!

OK, I see where you are going with this now. I do not think I tested the same thing as you asked about above.

Here is what I did in this last test IIRC:

0) I selected Natural in the service menu and set the gamma to my custom gamma (to pick up my grayscale tweaks) and switched color from 6500K to Custom1 to pick up my gain/offsets.

1) Entered service mode and selected the Natural CMS and wrote down its defaults. Then within the service menu I performed the below steps.

2) I measured the OOTB Natural setting with custom grayscale at both 75% and 100%. xy was oversaturated as anticipated but Y was very close to its target % of W for all colors.

3) With a 100% pattern I adjusted Red using the service menu CMS so that it was desaturated back to its Rec 709 point with Y spot on.

4) I switched to a 75% pattern and remeasured Red there. At this point I was out of service mode (RS20 kicked me out once calibration disc momentarily changed resolutions upon switching patterns). Upon measuring I saw red at this % level had not really moved from the point where I measured it previously (acted like I never performed step #2).

5) I then reentered the service menu and adjusted Red on this 75% pattern back down so that it was at its target Rec 709 point and Y was spot on. Then I switched back to 100% red and out of the service menu.

6) I remeasured with the 100% red and now the problem showed itself. Red was way undersaturated and Y was off, and clearly looked wrong by eye (washed out looking).

7) Then I went back to the 75% pattern in service mode, and fixed red back to its Rec 709 point with Y spot on. I went back and measured 100% red again, and now it was once again way over saturated and Y was off.

So in summary, if you calibrate using 100% patterns than at 75% the colors haven't really moved and remained over saturated at that level. If you calibrate at 75% then it desaturates the colors measured at 100%.

Based on your message I now see the angle you were after and I hadn't tried it... If I'm following you correctly you are thinking that we should perform steps 1-3 in the service menu CMS, and then step 5 in the USER menu.

So to recap your approach, you are thinking we should use the service menu CMS to make a "global"-like CMS adjustment with the 100% patterns. And then use the USER menu CMS to dial in the colors from there? And that hopefully doing it this way will not then push up the saturation at the higher % levels. Is this what you are thinking?

Please describe what you want me to try and I'll give it another try the next chance I have.
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post #659 of 1782
1/5/09 at 6:41am
Quote:
Originally Posted by lovingdvd View Post

OK, I see where you are going with this now. I do not think I tested the same thing as you asked about above.

Manni's thought here is exactly what I was thinking yesterday when I mentioned we may have twice the range on each control as we originally thought.

Edit: what you're thinking would be even better of course since it would imply the CMS between the service and user menus behave a bit differently from one another (sort of as if CMS in the service menu acted like gains and the user menu acted like cuts in grayscale calibration), but I don't think we'll be so lucky as to see this. If it does actually work out that way though, chances would be high of being able to attain a very good result with the CMS since that would give us much better odds of hitting a flat result across different % stimuli.
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post #660 of 1782
1/5/09 at 7:05am
Quote:
Originally Posted by lovingdvd View Post

So to recap your approach, you are thinking we should use the service menu CMS to make a "global"-like CMS adjustment with the 100% patterns. And then use the USER menu CMS to dial in the colors from there? And that hopefully doing it this way will not then push up the saturation at the higher % levels. Is this what you are thinking?

Please describe what you want me to try and I'll give it another try the next chance I have.

Yes, this is what I mean (and what Googer implied yesterday), which is only a valid approach if the settings in the service menu and the user menu can add to each other.

I suggested to try on green because it's the most oversaturated color, and to concentrate on saturation because it's the main control that's out of reach from the CMS in normal mode.

So to recap (and to try the theory), I suggest to:

- Reset the parameters in natural mode to default
- Enter the service mode
- Go to natural mode
- Set saturation for green to -30
- measure the gamut
- Set saturation for green to -30
- measure the gamut

If the two measured gamuts are different, and if green is within rec709 (or close), it means that we could use the fact that the CMS is accessible in natural mode to extend the range of the controls of the CMS (in a kind of two-pass process, one in service mode for broad strokes, two in normal mode for fine-tuning).

There is no point in trying further if green is not brought back enough saturation-wise after the two-passes, or if the service/normal adjustments are not cumulative (or if the result is still wrong at different levels of stimulus).

Hope this clarifies the principles...
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