Official JVC RS20 / HD750 Calibration and CMS thread - Page 3 - AVS Forum
Forum Jump: 
 
Thread Tools
Old 12-19-2008, 01:47 PM
AVS Club Gold
 
GlenC's Avatar
 
Join Date: Jun 2003
Location: Los Angeles - Whittier, CA
Posts: 2,555
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by SOWK View Post

Why would you prefer a 3 chip design?

That only calls for more "issues", at least in my thinking.

3-chip yields maximum bit depth of color, a full 6 mega pixels. A single chip is 1/3 or less (black segment on DLP) the bit depth. This is one reason that a 3-chip 720p projector can out perform a 1080p single chip. It is kind of like printing in color on photo paper vs. plain paper.

Glen Carter
Home Theater Calibration
www.ISFHT.com
GlenC is offline  
Sponsored Links
Advertisement
 
Old 12-19-2008, 01:48 PM
AVS Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 2,577
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 265 Post(s)
Liked: 173
Quote:
Originally Posted by TomHuffman View Post

Here are the CIE94 numbers for the THX preset.





Here are the CIE94 numbers on Mann01's latest "improved" technique using the CMS.





This is no better than what was available with the RS1/2.

Not an encouraging result. Other than red, none of the colors are within acceptable limits, and some of them (green, yellow, and cyan) are grossly inaccurate.

This is the result, despite the fact that the 1931 CIE chart looks reasonably good.



This just shows the inadequacy of relying exclusively on the CIE chart (especially the 1931 version) to grade color performance.

I haven't worked on one personally yet, but from the data of those who have it is beginning to look like the functionality built into the RS20 isn't a true CMS at all, but a pseudo-CMS with limited (if any) value.

You can select the THX preset, which gives reasonably good color but a quite yellowish gray scale; or, get a good gray scale with a custom calibration and live with the poor OOTB color. The included CMS controls don't seem to be able to improve it.

There may be very good reasons to like the RS20 (better optics in particular), but unless something new comes up we haven't seen yet or JVC offers a fix, better color performance isn't one of them.

I'm sure that this statement will annoy some of you, but that's what the data shows. If we get better data, then I'll be happy to revise this judgment.


Tom, I beg you not to take my data as meaningful (apart from proving I'm inexperienced but motivated!)

This is my first CMS calibration, I did train on my ACER fro greyscale, but it had no 11 steps gamma adjustments, and of course no full CMS. I am learning as I go, and as I progress I started to get a clear feeling that someone with more experience would nail this pretty easily. Of course seeing that LovingDVD who is much more experienced than me is hitting more or less the same walls crushes this theory, but I still believe there is a way to get there! I am wondering if those who have done it do not chime in to say how they did it because they make a living out of doing it (a perfectly valid reason in my books for not sharing trading secrets!)
Manni01 is offline  
Old 12-19-2008, 01:53 PM
AVS Special Member
 
Bulldogger's Avatar
 
Join Date: Dec 2000
Location: Clinton,MS
Posts: 6,687
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 35 Post(s)
Liked: 28
Quote:
Originally Posted by TomHuffman View Post

You can select the THX preset, which gives reasonably good color but a quite yellowish gray scale; or, get a good gray scale with a custom calibration and live with the poor OOTB color.

It appears we need to see what's going on with the THX mode and if it can be tinkered with via the service menu to improve the gray scale. That may be the only hope.

Never become so involved with something that it blinds you.
Bulldogger is online now  
Old 12-19-2008, 02:03 PM
AVS Special Member
 
TomHuffman's Avatar
 
Join Date: Jan 2003
Location: Springfield, MO
Posts: 6,478
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 80 Post(s)
Liked: 249
Quote:
Originally Posted by Manni01 View Post

Tom, I beg you not to take my data as meaningful (apart from proving I'm inexperienced but motivated!)

This is my first CMS calibration, I did train on my ACER fro greyscale, but it had no 11 steps gamma adjustments, and of course no full CMS. I am learning as I go, and as I progress I started to get a clear feeling that someone with more experience would nail this pretty easily. Of course seeing that LovingDVD who is much more experienced than me is hitting more or less the same walls crushes this theory, but I still believe there is a way to get there!

Not just LovingDVD. Cine4Home reported much the same thing as well, though not as explicitly.

The fact that you are new to this is not particularly important. Did you use a white pattern that was the same level of stimulus as the color patterns? Unless you did not, the data is the data. It doesn't change just because the person collecting it hasn't has a lot of experience. The mere fact that both of you report that lowering the green saturation tool has almost no effect on green saturation is, by itself, pretty strong evidence that the CMS has a pretty severe design flaw.

What you guys were finally left with was just lowering the main color control and then trying to compensate for the loss in luma by raising the brightness controls on the various colors, which is at best a kluge. You might want to see if you can get the brightness of green, yellow, and cyan higher without also raising their saturation levels back to where they were.

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

TomHuffman is offline  
Old 12-19-2008, 02:04 PM
Advanced Member
 
deandob's Avatar
 
Join Date: May 2002
Location: Brisbane, Australia
Posts: 821
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Possibly to get color nirvana, a combination of adjusting the CMS as far as it will go then tweaking system settings in the service menu is needed???
deandob is offline  
Old 12-19-2008, 02:56 PM
AVS Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 2,577
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 265 Post(s)
Liked: 173
Quote:
Originally Posted by TomHuffman View Post

Not just LovingDVD. Cine4Home reported much the same thing as well, though not as explicitly.

The fact that you are new to this is not particularly important. Did you use a white pattern that was the same level of stimulus as the color patterns? Unless you did not, the data is the data. It doesn't change just because the person collecting it hasn't has a lot of experience. The mere fact that both of you report that lowering the green saturation tool has almost no effect on green saturation is, by itself, pretty strong evidence that the CMS has a pretty severe design flaw.

What you guys were finally left with was just lowering the main color control and then trying to compensate for the loss in luma by raising the brightness controls on the various colors, which is at best a kluge. You might want to see if you can get the brightness of green, yellow, and cyan higher without also raising their saturation levels back to where they were.

Cine4Home posted an almost perfect corrected gamut (although without the raw data so it's difficult to know how the Y values were, but I would trust someone like Ekkehart). ColdMachine posted he had no problems following Ekkeharts "hint" to adjust the gamut to perfection. None of those who have "cracked it" have said how they did it exactly, but I believe you stand a better chance to get it right if you are more experienced than me, not from a collecting data point of view (I hope I got that right!), but from a "strategy" point of view. I'm making stabs in the dark, and discovering as I go how the principles work, which is obviously not the bet way to tackle a convoluted CMS like the 750's.

In my last attempt, as I explained, I didn't have at hand the Y percentages for each primary/secondary, so although I did get a better result, it's not a surprise it's still not perfect.

What I mean by strategy is what's the best way to get you from an uncorrected gamut where saturation/hue only can't get you close enough on th x,y space to the best "starting point" to play with saturation/hue before adjusting with brightness. Do you only adjust the color setting? Do you also adjust the tint (which I haven't done in my last attempt as it looked like it was making things worse)? How far down do you push the color? -14 was not enough, so I went all the way to -30 (the maximum) to test the theory, but something in between may allow, after saturation/hue/brightness correction, to get a perfect gamut.

I hope this makes sense. I'm going, this week-end if I can (just caught bad cold!) to try starting from scratch on a new user setting, following exactly the procedure you outline in your very helpful guide, and using the Y percentages you provide to try and get something closer. I'm sure LovingDVD (and others) will try as well, and hopefully we'll get something that's closer...

One question to help me understand what's still wrong in my values: when you say that apart from red, my colors are grossly inaccurate, could you quantify/explain why? Is there something flawed in the theory I am exploring, which is to lower the color value (we still need to find the optimum parameter) to be able to use hue and saturation to bring the colors spot on on the x,y space, and then use the brightness control to compensate for the loss of luminance generated by the lowering of the color control and get Y closer?

If the theory is not flawed, I really believe that it is possible to greatly improve the results (especially if using the correct target Y data as a reference, which I didn't have druing my last attempt, I was just trying to lower dE empirically). If the theory is flawed, then I'm clueless at this stage regarding how to make progress...

Hope this makes some kind of sense. It's hard to argue with your teacher!
Manni01 is offline  
Old 12-19-2008, 05:17 PM
AVS Special Member
 
Lawguy's Avatar
 
Join Date: Sep 2004
Posts: 5,709
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 11
Stuck in New Orleans due to snow in NY. It is unclear when I will get home. RS20 awaits.

Affable Nitwit
Lawguy is offline  
Old 12-19-2008, 05:29 PM
AVS Special Member
 
Bulldogger's Avatar
 
Join Date: Dec 2000
Location: Clinton,MS
Posts: 6,687
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 35 Post(s)
Liked: 28
Quote:
Originally Posted by Lawguy View Post

Stuck in New Orleans due to snow in NY. It is unclear when I will get home. RS20 awaits.

Well at 6:27 pm, it's 71 degrees here. If you are out in Kenner at the airport, that's boring but at least you can enjoy the warm weather.

Never become so involved with something that it blinds you.
Bulldogger is online now  
Old 12-19-2008, 05:56 PM
AVS Special Member
 
Lawguy's Avatar
 
Join Date: Sep 2004
Posts: 5,709
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 11
Quote:
Originally Posted by Bulldogger View Post

Well at 6:27 pm, it's 71 degrees here. If you are out in Kenner at the airport, that's boring but at least you can enjoy the warm weather.

I am at the Intercontinental downtown. I guess Ill have to force myself to head into the quarter. Poor me.

Affable Nitwit
Lawguy is offline  
Old 12-19-2008, 06:06 PM
AVS Special Member
 
TomHuffman's Avatar
 
Join Date: Jan 2003
Location: Springfield, MO
Posts: 6,478
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 80 Post(s)
Liked: 249
Quote:
Originally Posted by Manni01 View Post

Cine4Home posted an almost perfect corrected gamut (although without the raw data so it's difficult to know how the Y values were, but I would trust someone like Ekkehart).

Just as I did. Please read my post again. You can show a nearly perfect gamut on a CIE chart, and yet have grossly inaccurate color for precisely the reason you mention.

Quote:
Originally Posted by Manni01 View Post

One question to help me understand what's still wrong in my values: when you say that apart from red, my colors are grossly inaccurate, could you quantify/explain why? Is there something flawed in the theory I am exploring, which is to lower the color value (we still need to find the optimum parameter) to be able to use hue and saturation to bring the colors spot on on the x,y space, and then use the brightness control to compensate for the loss of luminance generated by the lowering of the color control and get Y closer?

To answer that question all you have to do is look at the LSH values. Those need to be no more than +- 2%. They are not even close.

There is nothing wrong with the theory. The problem is in what's possible given the tools you have to work with. Since the green saturation control doesn't work AT ALL, the only thing you can do for green is to lower the main Color control, which lowers both saturation and brightness for all colors. In theory if you can then raise green brightness back to where it should be without simultaneously raising the saturation again, then this would work. But I assumed that you'd already tried that and found either that the green brightness control either doesn't have sufficient range of adjustment OR that it also raises saturation as well leaving you right back where you started. IF using the Color control alone to reduce saturation and then using the hue/brightness controls to individually adjust each color's brightness and hue, then it is possible. Do the controls allow you to do this?

It is a simple proposition. Can you get the green xy where it should be and the brightness close to 71% of reference white both at the same time? Your most recent set of numbers had green at just over 40% of reference white and it was still considerably oversaturated and the hue was screwed up as well.

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

TomHuffman is offline  
Old 12-19-2008, 06:23 PM
AVS Special Member
 
WOLVERNOLE's Avatar
 
Join Date: Jun 2001
Location: DUMFRIES, VA USA
Posts: 2,546
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 12

Not that I was one bit prophetic, but I sensed that the CMS in the RS-20 was going to be thee deal-MAKER over the RS-2/HD100. It still would appear to be a better product at a great price, but does this sense of the CMS being...well, at least somewhat ineffective, make it a deal-BREAKER ? Dunno.
WOLVERNOLE is offline  
Old 12-19-2008, 07:31 PM
Advanced Member
 
KTTV Images's Avatar
 
Join Date: Sep 2005
Location: San Jose, CA
Posts: 601
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by TomHuffman View Post


......What you guys were finally left with was just lowering the main color control and then trying to compensate for the loss in luma by raising the brightness controls on the various colors, which is at best a kluge. You might want to see if you can get the brightness of green, yellow, and cyan higher without also raising their saturation levels back to where they were.

Tom,
One set of controls that no one has brought into the picture are the 6 controls ( Gain and Offset ) for adjusting the gray scale to D65. Yes, I know juggling these will destroy the gray scale over the full 0 to 100 IRE input range but it seems to me there is one possible new strategy here no one has tried.

First let me state an assumption I found to be true on 2 different Sony SXRD Rear projectors I've had: It is possible to achieve a correct gray scale of D65 with more than one set of settings of these 6 controls. For example- suppose you found good settings of the 6 controls for D65. Now if you reduce the settings of, say, the red Offset (Dark part) by 3 clicks , you will find that reducing the Offset of the other 2 colors in a similar way will bring the darker portion of the gray scale back into the D65 range. You could do the same with the 3 Gain (Bright part) controls for the brighter portion of the gray scale. For various reasons I tried this on the Sony SXRD's and it worked.

Now, what has happened if we make the changes described above is that we have changed the ABSOLUTE levels of the operating points for Red, Green and Blue. IN electronic analog terms the normal operating points for all 3 primary colors is now at a lower voltage than it was before. Now, this is the point .. if there is a constraint on the Green primary Saturation control ... perhaps by shifting the operating point downward the Green saturation control will begin to function .. at least a little bit. There is no good reason to believe it will.. the idea is to simply try it out and see what happens.. we are desperate here.

I do not predict this will in fact help .. it is just that in an exhaustive attempt to get the Green CMS Saturation control to work it is easy to try and may be worth a wild shot.

What do you think?

KT
KTTV Images is offline  
Old 12-19-2008, 07:51 PM
AVS Special Member
 
Bulldogger's Avatar
 
Join Date: Dec 2000
Location: Clinton,MS
Posts: 6,687
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 35 Post(s)
Liked: 28
Quote:
Originally Posted by WOLVERNOLE View Post


Not that I was one bit prophetic, but I sensed that the CMS in the RS-20 was going to be thee deal-MAKER over the RS-2/HD100. It still would appear to be a better product at a great price, but does this sense of the CMS being...well, at least somewhat ineffective, make it a deal-BREAKER ? Dunno.

I would think it's deal breaker if you are happy with the light output of the RS2. However, the RS2 is just to dim for someone like me who insist on larger AT screens, so more light would motivate me to upgrade. It also depends on how happy you are with the color performance of the RS2. If you are both happy with lumens and colors of the RS2, the RS20 would seem to not offer enough. If only unhappy with color performance of the RS2, then the Lumagen would seem to make more sense as at least it performs exactly as advertised.

Never become so involved with something that it blinds you.
Bulldogger is online now  
Old 12-19-2008, 09:42 PM
AVS Special Member
 
TomHuffman's Avatar
 
Join Date: Jan 2003
Location: Springfield, MO
Posts: 6,478
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 80 Post(s)
Liked: 249
Quote:
Originally Posted by KTTV Images View Post

Tom,
One set of controls that no one has brought into the picture are the 6 controls ( Gain and Offset ) for adjusting the gray scale to D65. Yes, I know juggling these will destroy the gray scale over the full 0 to 100 IRE input range but it seems to me there is one possible new strategy here no one has tried.

First let me state an assumption I found to be true on 2 different Sony SXRD Rear projectors I've had: It is possible to achieve a correct gray scale of D65 with more than one set of settings of these 6 controls. For example- suppose you found good settings of the 6 controls for D65. Now if you reduce the settings of, say, the red Offset (Dark part) by 3 clicks , you will find that reducing the Offset of the other 2 colors in a similar way will bring the darker portion of the gray scale back into the D65 range. You could do the same with the 3 Gain (Bright part) controls for the brighter portion of the gray scale. For various reasons I tried this on the Sony SXRD's and it worked.

Now, what has happened if we make the changes described above is that we have changed the ABSOLUTE levels of the operating points for Red, Green and Blue. IN electronic analog terms the normal operating points for all 3 primary colors is now at a lower voltage than it was before. Now, this is the point .. if there is a constraint on the Green primary Saturation control ... perhaps by shifting the operating point downward the Green saturation control will begin to function .. at least a little bit. There is no good reason to believe it will.. the idea is to simply try it out and see what happens.. we are desperate here.

I do not predict this will in fact help .. it is just that in an exhaustive attempt to get the Green CMS Saturation control to work it is easy to try and may be worth a wild shot.

What do you think?

I don't have one to try it on. It sounds implausible, but anything is worth a try. Just turning down the contrast control would be similar and simpler, though this would substantially reduce the light output.

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

TomHuffman is offline  
Old 12-19-2008, 10:16 PM
AVS Addicted Member
 
millerwill's Avatar
 
Join Date: Apr 2004
Location: Berkeley, CA
Posts: 11,445
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
Liked: 47
Well, in reading this thread I'm glad I chose to get Jason's 'calibration service'; I hope he had the magic hand. My RS20 is scheduled to arrive Tuesday, so I'll find out soon.

I have recently gotten a I1LT, though, and want to start learning about how to do gray scale, cms, etc., but it seems clear that the RS20 is not the easiest unit to start with. It will be nice to have Jason's results in User1, and then I copy them into User2 and start screwing around from there. At some point down the line I presume that some of you 'old hands' will post your settings so that us novices can use them as a starting point. Merry Christmas to us all.
millerwill is offline  
Old 12-19-2008, 11:02 PM
AVS Special Member
 
Kris Deering's Avatar
 
Join Date: Oct 2002
Location: The Pacific Northwet
Posts: 7,238
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 397
Quote:
Originally Posted by SOWK View Post

What would you give up, except better black levels? And yes I know this can make a big difference.

The Samsung I think would be just as good/superior in most every other area of an image quality standpoint... no?

And before anyone posts, SOWK is bashing JVC again, I'm not bashing, just honestly asking.

It is more than black levels. The JVC has a better overall dynamic range, so even real low APL scenes just look better. And three chip designs have a far more natural color balance than single chip, though single chip do a superb job with overall resolution.

I'm sticking with my current projector until something comes along and REALLY trumps it, not some minor improvement.

Senior Video Editor
Secrets of Home Theater and High Fidelity

Click Here To See My Current Setup
Kris Deering is offline  
Old 12-19-2008, 11:05 PM
AVS Special Member
 
Kris Deering's Avatar
 
Join Date: Oct 2002
Location: The Pacific Northwet
Posts: 7,238
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 397
Quote:
Originally Posted by Hughman View Post

Kris,

Darin has commented a couple times since the RS20 comparison that you've tweaked your RS2's color gamut and it looks very good, are you using an outboard processor or have you discovered something worth sharing?

Not using a Radiance, though I have one here in the office. At some point I might try it out again. I tried it early on and it had too many issues with my setup to make it a viable solution in my particular situation.

I've found a very nice settling point with my projector. Saturation is far better than it was before but it took its toll on overall luminance. But looking at the image and not the computer monitor with the readings results in a picture that is more the livable, it is gorgeous. I wish I could dial it in a bit better in terms of overall accuracy but I've found a great place to settle on that works for me and I've yet to have a complaint from vistors; videophiles or not.

Senior Video Editor
Secrets of Home Theater and High Fidelity

Click Here To See My Current Setup
Kris Deering is offline  
Old 12-19-2008, 11:55 PM
AVS Special Member
 
lovingdvd's Avatar
 
Join Date: Jul 2002
Posts: 9,085
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 208 Post(s)
Liked: 74
Quote:
Originally Posted by Kris Deering View Post

...I've found a very nice settling point with my projector. Saturation is far better than it was before but it took its toll on overall luminance. But looking at the image and not the computer monitor with the readings results in a picture that is more the livable, it is gorgeous. I wish I could dial it in a bit better in terms of overall accuracy but I've found a great place to settle on that works for me and I've yet to have a complaint from vistors; videophiles or not.

Kris - is this the RS20 or the RS2 you are talking about?
lovingdvd is online now  
Old 12-20-2008, 12:02 AM
AVS Special Member
 
lovingdvd's Avatar
 
Join Date: Jul 2002
Posts: 9,085
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 208 Post(s)
Liked: 74
The default colors on the RS20 are really juiced up. When you switch to THX just as a quick comparison it puts it into perspective. I'd actually like to come up with something in between both settings. For instance I like the default colors on the RS1, but the defaults on RS20 are a bit too much for my tastes.

Red is the most objectionable. It is just too deep. It reminds me of how the Sharp 10K was with its default settings. The 10K, however, had a working CMS that was easy to use so it wasn't an issue.

Hopefully we will be able to come up with an approach to taming the colors or at least improving them. For instance even if Y isn't in an ideal spot, the colors may still look a lot better than the OOTB settings.

Tom - to answer your question from several posts back, yes I do believe the RS20 will enable that type of configuration - whereby color can be lowered globally and then just the hue and brightness of the 6 colors can be tweaked without touching their saturation control. I do believe the settings will enable these types of tweaks. Whether or not that actually yields good results is of course another matter.
lovingdvd is online now  
Old 12-20-2008, 12:30 AM
AVS Special Member
 
lovingdvd's Avatar
 
Join Date: Jul 2002
Posts: 9,085
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 208 Post(s)
Liked: 74
Aside from the color gamut which I haven't attempted to tackle yet, I was able to get very good results from a calibration I did last night.

In summary I was able to dial in D65 with a dE of less than 3 for the entire range of 5-100. Most of the dE readings were about 1.5, but I could have had most of these under 1.0. However doing so would have left 100% with a dE of 3.6. So instead I decided to sacrifice a tad (moving the dE from 0.5 to 1.5ish) in most of the range to get the dE at 100 under 3.0 (OTTOMH I think it was about 2.6).

At first I dialed in a flat grayscale from 20-100 (all with a dE under 3) just by using the global gains/offsets. This went pretty quickly. However this left 5-15% with high dE. For instance I think 5% was over 12 dE and 10% was 6ish.

So I set out to use the RGB controls in the custom gamma to flatten things out. This turned out to be a major undertaking which I spent many hours on. Ultimately though it was worth it to get 5-100% all under 3 dE.

One slight downside is that my gamma dropped a bit from 2.2 to 2.17. I ran out of time to work on correcting it. I understand from GlenC that with his RS2, if you touch the White point it then throws the grayscale off. So this may cause me to have to rebalance everything. Sigh. Not sure if that will be worth it, as this calibration was pretty grueling. You can read about some of the challenges I hit by scanning back in this thread.

I am very pleased to report, and I'm sure many of you will be happy to read, that I did measure on/off CR at 45,685:1! This is at mid throw (maybe a bit beyond mid throw - about 15' from a 106" diag) with the iris fully closed (-15) and with high lamp. It yielded 305 lumens post calibration in this mode. This equates to about 12fL on my 1.3 gain Firehawk which is PLENTY bright. As the bulb ages I will slowly open up the iris to maintain this same brightness level.

I believe this measured CR comes in at the higher end based on what cine4home published with his pre-production unit. In particular from max throw he reported 48,100:1 with high lamp D65 and iris -15 with 230 lumens. I say "higher end" because even though this measurement was less than 48,100:1 it was done at mid throw. I would anticipate that at max throw that his number is based on it would surpass that number. Supposedly there is a fair amount of variability in CR from unit to unit, so YMMV in either direction.

I have confidence in my measurements. I am using a Spyder II meter trained to an i1 Pro. I have used this combination over the years and found it very effective because it combines the color accuracy of the i1 with the low level light reading abilities (and ability to read directly in front of the pj) of the Spyder. As a frame of reference I measured about 14,000:1 with my RS1 using this same equipment with the same exact setup (same throw etc). So getting 3x the contrast is certainly a nice improvement!

After working with the unit I get the feeling that calibration settings may not carry over so well from pj to pj. Nonetheless I will post the values in a few days once I have time to double check everything and see if any other tweaks are needed.

I can tell you that the OOTB grayscale in the default 6500K mode has too much green and comes in at about 5.5 dE across the scale, at least on my unit. It is pretty clear when viewing that its too green. This was a bit surprising because the RS1 (and presumably the RS2) had near perfect grayscale OOTB (at least as far as factory configured grayscales go).
lovingdvd is online now  
Old 12-20-2008, 01:45 AM
AVS Special Member
 
SOWK's Avatar
 
Join Date: Dec 2004
Location: Wauwatosa, WI
Posts: 4,093
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 227 Post(s)
Liked: 128
Quote:
Originally Posted by lovingdvd View Post

Aside from the color gamut which I haven't attempted to tackle yet, I was able to get very good results from a calibration I did last night.

In summary I was able to dial in D65 with a dE of less than 3 for the entire range of 5-100. Most of the dE readings were about 1.5, but I could have had most of these under 1.0. However doing so would have left 100% with a dE of 3.6. So instead I decided to sacrifice a tad (moving the dE from 0.5 to 1.5ish) in most of the range to get the dE at 100 under 3.0 (OTTOMH I think it was about 2.6).

At first I dialed in a flat grayscale from 20-100 (all with a dE under 3) just by using the global gains/offsets. This went pretty quickly. However this left 5-15% with high dE. For instance I think 5% was over 12 dE and 10% was 6ish.

So I set out to use the RGB controls in the custom gamma to flatten things out. This turned out to be a major undertaking which I spent many hours on. Ultimately though it was worth it to get 5-100% all under 3 dE.

One slight downside is that my gamma dropped a bit from 2.2 to 2.17. I ran out of time to work on correcting it. I understand from GlenC that with his RS2, if you touch the White point it then throws the grayscale off. So this may cause me to have to rebalance everything. Sigh. Not sure if that will be worth it, as this calibration was pretty grueling. You can read about some of the challenges I hit by scanning back in this thread.

I am very pleased to report, and I'm sure many of you will be happy to read, that I did measure on/off CR at 45,685:1! This is at mid throw (maybe a bit beyond mid throw - about 15' from a 106" diag) with the iris fully closed (-15) and with high lamp. It yielded 305 lumens post calibration in this mode. This equates to about 12fL on my 1.3 gain Firehawk which is PLENTY bright. As the bulb ages I will slowly open up the iris to maintain this same brightness level.

I believe this measured CR comes in at the higher end based on what cine4home published with his pre-production unit. In particular from max throw he reported 48,100:1 with high lamp D65 and iris -15 with 230 lumens. I say "higher end" because even though this measurement was less than 48,100:1 it was done at mid throw. I would anticipate that at max throw that his number is based on it would surpass that number. Supposedly there is a fair amount of variability in CR from unit to unit, so YMMV in either direction.

I have confidence in my measurements. I am using a Spyder II meter trained to an i1 Pro. I have used this combination over the years and found it very effective because it combines the color accuracy of the i1 with the low level light reading abilities (and ability to read directly in front of the pj) of the Spyder. As a frame of reference I measured about 14,000:1 with my RS1 using this same equipment with the same exact setup (same throw etc). So getting 3x the contrast is certainly a nice improvement!

After working with the unit I get the feeling that calibration settings may not carry over so well from pj to pj. Nonetheless I will post the values in a few days once I have time to double check everything and see if any other tweaks are needed.

I can tell you that the OOTB grayscale in the default 6500K mode has too much green and comes in at about 5.5 dE across the scale, at least on my unit. It is pretty clear when viewing that its too green. This was a bit surprising because the RS1 (and presumably the RS2) had near perfect grayscale OOTB (at least as far as factory configured grayscales go).

What meter(s) are you useing?

I1Pro and SpyderII? or Just SpyderII?

Also how are you getting on/off contrast mesrments?
SOWK is offline  
Old 12-20-2008, 05:40 AM
 
scottyb's Avatar
 
Join Date: Mar 2000
Location: mound,mn,usa
Posts: 3,537
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Kris Deering View Post

I've found a very nice settling point with my projector. Saturation is far better than it was before but it took its toll on overall luminance. But looking at the image and not the computer monitor with the readings results in a picture that is more the livable, it is gorgeous. I wish I could dial it in a bit better in terms of overall accuracy but I've found a great place to settle on that works for me and I've yet to have a complaint from vistors; videophiles or not.


Kris,
Can you post your settings or at least where you tweaked for others of us to have a starting point. I know all projectors are different. My biggest question is what # your "color setting" is at in the main menu?

Thanks Kris.
scottyb is offline  
Old 12-20-2008, 06:01 AM
AVS Special Member
 
Kris Deering's Avatar
 
Join Date: Oct 2002
Location: The Pacific Northwet
Posts: 7,238
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 397
Color is at -25. I am on travel now so no go on other settings. A previous poster asked what projector. I have a rs2. I don't have a rs20 or 750. I simply tinkered around with a friends.

Senior Video Editor
Secrets of Home Theater and High Fidelity

Click Here To See My Current Setup
Kris Deering is offline  
Old 12-20-2008, 06:12 AM
AVS Special Member
 
Lawguy's Avatar
 
Join Date: Sep 2004
Posts: 5,709
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 11
Has anyone figured out how to get into the service menu yet?

Affable Nitwit
Lawguy is offline  
Old 12-20-2008, 07:48 AM
AVS Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 2,577
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 265 Post(s)
Liked: 173
Quote:
Originally Posted by TomHuffman View Post

Just as I did. Please read my post again. You can show a nearly perfect gamut on a CIE chart, and yet have grossly inaccurate color for precisely the reason you mention.

To answer that question all you have to do is look at the LSH values. Those need to be no more than +- 2%. They are not even close.

There is nothing wrong with the theory. The problem is in what's possible given the tools you have to work with. Since the green saturation control doesn't work AT ALL, the only thing you can do for green is to lower the main Color control, which lowers both saturation and brightness for all colors. In theory if you can then raise green brightness back to where it should be without simultaneously raising the saturation again, then this would work. But I assumed that you'd already tried that and found either that the green brightness control either doesn't have sufficient range of adjustment OR that it also raises saturation as well leaving you right back where you started. IF using the Color control alone to reduce saturation and then using the hue/brightness controls to individually adjust each color's brightness and hue, then it is possible. Do the controls allow you to do this?

It is a simple proposition. Can you get the green xy where it should be and the brightness close to 71% of reference white both at the same time? Your most recent set of numbers had green at just over 40% of reference white and it was still considerably oversaturated and the hue was screwed up as well.

Thanks for the clarification. I find it quite worrying that you seem to imply that someone like Ekkehart would post a perfect gamut not realising that the Y values are completely wrong. I was able to get a similar gamut, and green went up when I tried to adjust brightness. You are right, given the starting point I chose (-30 for the color control), I couldn't compensate brightness enough for the green. I did not bring me back to the staarting point though, as it was better than the uncorrected gamut (from anb x,y point of view).

Regarding the saturation control for green not wroking AT ALL, this is not true. It does work, but witout touching the color control, it will only bridge about half the gap separating its starting point in the incorrected gamut from its "correct" position on the x,y plan. So its range is not powerful enough to do its job properly, but it is working (it has an effect!).

As long as the theory is not flawed, I'm going to give it another try, and I'll report here. I may have to take into acount the fact that when pushing brighness up, it has an effect on saturation, so start with a green inside the gamut (if I can) before I correct the brightness, and see if I end up with a green spot on in the ed. I did the opposite in my last attempt (first pushed it back with saturation until it was spot on, then played with brightness, and it pushed green outside).
Manni01 is offline  
Old 12-20-2008, 07:54 AM
AVS Special Member
 
Manni01's Avatar
 
Join Date: Sep 2008
Posts: 2,577
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 265 Post(s)
Liked: 173
Quote:
Originally Posted by millerwill View Post

Well, in reading this thread I'm glad I chose to get Jason's 'calibration service'; I hope he had the magic hand. My RS20 is scheduled to arrive Tuesday, so I'll find out soon.

I have recently gotten a I1LT, though, and want to start learning about how to do gray scale, cms, etc., but it seems clear that the RS20 is not the easiest unit to start with. It will be nice to have Jason's results in User1, and then I copy them into User2 and start screwing around from there. At some point down the line I presume that some of you 'old hands' will post your settings so that us novices can use them as a starting point. Merry Christmas to us all.

Millerwill, I hope that Jason has been able to get the gamut perfect in the user1 settings, it would be good to get a confirmation it's posible. Please measure and report!

Unfortunately,you won't be able to copy automatically the user1 settings to another user memory, for two reasons:
- there are no global settings copy function (that I could find), you can only copy the gamma setings from a gamma user setting to another (three total).
- you can't copy the advanced settings in the CMS, which is where the gamut is "tweaked".

Of course nothing stops you from copying all the settings manually, and play with a copy of the gamma settings.

I really hope that someone will provide the code to access the service menu. Ideally, you'd want to be able to copy the THX settings (which probably has the closest gamut we could get from the 750, unfortunately with a bit too much green/yellow) and tweak from there, at least to get a better greyscale.
Manni01 is offline  
Old 12-20-2008, 08:14 AM
AVS Special Member
 
Chris Dallas's Avatar
 
Join Date: Oct 2001
Location: Toronto, Ontario, Canada & Malibu California.
Posts: 1,248
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by lovingdvd View Post

I will post the values in a few days once I have time to double check everything and see if any other tweaks are needed.

lovingdvd that would be great and thanks for all the hard work you've done for everyone to follow over the years as well.

Just curious though, will you be changing your nick soon to lovinghd or lovingbluray to stay up to date?

Cheers
Chris

Sony VPL-VW500ES, 150" width 2.35:1 screen, Proud owner of 1 of 399 Enzo Ferrari's in the world, a gorgeous yellow Ferrari 599GTB, + a 1970 Road Runner see it here

Chris Dallas is offline  
Old 12-20-2008, 09:25 AM
AVS Special Member
 
JeffY's Avatar
 
Join Date: Mar 2001
Location: England
Posts: 3,667
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Here is my first go, using a combination of Lumagen HDP gamut controls and CMS on the JVC. The main 2 issues I'm having is Cyan saturation and Green luminance levels. The other colours are slightly oversaturated, but that was done by me on purpose because I prefer it that way. The CMS seems to work quite well, it's just that the projector needs bigger adjustments than they allow for in the software.

JeffY is offline  
Old 12-20-2008, 09:48 AM
AVS Special Member
 
TomHuffman's Avatar
 
Join Date: Jan 2003
Location: Springfield, MO
Posts: 6,478
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 80 Post(s)
Liked: 249
Quote:
Originally Posted by Manni01 View Post

I find it quite worrying that you seem to imply that someone like Ekkehart would post a perfect gamut not realising that the Y values are completely wrong.

I'm not sure he did realize it, or even measure it. From his write-up it looks like he was solely concerned with reigning in the saturation of the colors to get a reasonably good CIE chart, something I was able to do with the provided data as well. If he had any inkling that this was not sufficient to get the color even reasonably accurate, then there's no indication of it, because he mentions no metric other than the CIE chart.

I think you overestimate how many professional reviewers entirely understand this issue, much less the consumers they write for. Perhaps they do understand it, but for whatever reason it is, with a few rare exceptions, not mentioned in the reviews I routinely read.

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

TomHuffman is offline  
Old 12-20-2008, 09:54 AM
AVS Special Member
 
JeffY's Avatar
 
Join Date: Mar 2001
Location: England
Posts: 3,667
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Tom,

Given the choice would you go for an over saturated colour but correct luminance levels or correct saturation but badly affected luminance, or do something in between?
JeffY is offline  
 
Thread Tools


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off