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Quote:
Originally Posted by TomHuffman /forum/post/0


I thought it would be useful to maintain a database of displays that include a functional CMS.

I take it you don't consider the pioneer elite CMS functional. Does it allow for any improvement in color or is it just worthless?
 

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Discussion Starter #22

Quote:
Using the Avia color decoder test - it appears that it has a bit of a red push. Will that give me some problems?

This display has no color decoder adjustment. In fact, it has no CMS. All you've got to work with is the Color control. If you have serious red push, then it's a trade-off. Getting red right, means you have to lower the intensity of B and G more than ideal. Find some compromise that's acceptable.


If you are interested in this stuff, you might consider investing in a display that offers more control over the image quality.
 

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Discussion Starter #23

Quote:
Originally Posted by zoyd /forum/post/0


I take it you don't consider the pioneer elite CMS functional. Does it allow for any improvement in color or is it just worthless?

I'd say worthless describes it pretty well. You can move the color points with it some, but it screws up the gray scale.
 

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Hello Tom,

Most of this is still a bit beyond me, I really appreciate your posts. As for your data base on CMS displays, I have a Sanyo PLV-Z4 front PJ that allows color level, color phase and gamma. Do not have anything but DVE for calibrating so I do not know if these are truly functional, they do offer some change but, I cannot tell what they are effecting. Do you know what they mean by color phase?
 

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Quote:
Originally Posted by TomHuffman /forum/post/0


This display has no color decoder adjustment. In fact, it has no CMS. All you've got to work with is the Color control. If you have serious red push, then it's a trade-off. Getting red right, means you have to lower the intensity of B and G more than ideal. Find some compromise that's acceptable.

I'll try to find a decent compromise. I would guess that I should measure 75% R, G, and B to see how close I am and then sort of try to split the difference? Using the tint to adjust cyan to the target is still something I need to do.

Quote:
Originally Posted by TomHuffman /forum/post/0


If you are interested in this stuff, you might consider investing in a display that offers more control over the image quality.

I am and you are right. Right now I am sort of 'tryin' to make a silk purse out of a cow's ear'. Just need to get the funds scraped together. I will say this, all you guys have certainly helped me to acheive much better image fidelty..... Sorry, I just like to say/write image fidelity - it's pretty cool!


Thanks again for the help.
 

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Tom, you can add the Sharp XV-Z3000 and Sharp DT-500 to the CMS list. These doesn't however have user menu cuts for any color, and only has R and B drive. I assume full control is available via a service menu to cuts/drives.
 

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Quote:
Originally Posted by Jason 1973 /forum/post/0


Hello Tom,

Most of this is still a bit beyond me, I really appreciate your posts. As for your data base on CMS displays, I have a Sanyo PLV-Z4 front PJ that allows color level, color phase and gamma. Do not have anything but DVE for calibrating so I do not know if these are truly functional, they do offer some change but, I cannot tell what they are effecting. Do you know what they mean by color phase?

phase is tint/hue - and it has a very narrow range of adjustment.


You cannot reduce color saturation - and the color level is only good enough range to fix the displays red push - if your source has red push you are screwed. Also it only works on a narrow range of tints - so you fix red - then notice orange and crimson are still off. A true CMS does not work that way!


I call such budget systems color replacement systems - because you are adjusting colors that are nearby to colors that you frame grab from the video.

Their CMS gamma is wierd - I assume this is a gamma applied to that color in the video - but it already has a very wide ranging master gamma slider that is great - as well as a service menu with RGB gamma to fine tune when working on greyscale. So I don't really see what use it has.
 

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Does the Panasonic's AE1000 or the Sanyo Z5 elevate onto this list?


Bill
 

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Discussion Starter #29
I haven't seen either, but Kraz insists that the Sanyo is an ersatz CMS only with no real value. From reading about the Panasonic, it sounds very similar, but I'll I withhold judgment until I actually see one.
 

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Bill


You need gamut testpattern to prove if it is a CMS or "CRS". AVIA PRO has a sequence, DisplaYMate calibration patterns - and most computer based calibration softwares show the CIE gamut - but you also need to run the tests at various brightness levels. A true CMS is redefining RGB gamut in all 3D - brightness, chroma (saturation) and hue - if they just replace those RGB - then they have not fixed the gamut as other colors are still screwed.


I had heard the Panny would fix that brightness level - but other brightness levels were still screwed - but no experience with it.
 

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Discussion Starter #31
Randy Tomlinson has a review of the HLS Samsung DLP rear projector in this edition of UltimateAV that comments extensively on its CMS. It's worth the read.

http://www.guidetohometheater.com/re...vs/507sam5688/


My only quibble is his insinuation that you simply can't do decent color correction without a $15,000 Photo Research spectroradiometer. Just silly.
 

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Discussion Starter #33

Quote:
It has controls for Color, Tint and Brightness.

This is not what we mean by a Color Management System. The NTSC specification requires ALL displays to have adjustments for Color, Tint, Sharpness, Brightness, and Contrast. A CMS goes significantly beyond this.
 

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Quote:
Originally Posted by zoyd /forum/post/0


This agrees with krasmuzik's comment about shorting the color brightness slightly to get the best perceptual results(assuming you're starting from outside the triangle). I was also surprised to see that dE was such a strong function of L*

I missed this comment my first pass, but this is a point I tried to make a while ago here:
http://www.avsforum.com/avs-vb/showt...&post6637132


I have also posted a critique of the dE(u'v') method as going too far in the other direction, but that is for a different thread...


Bill
 

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Quote:
This is not what we mean by a Color Management System. The NTSC specification requires ALL displays to have adjustments for Color, Tint, Sharpness, Brightness, and Contrast. A CMS goes significantly beyond this.

For EACH COLOR
. (Sorry, I was a bit short there) One can store up to eight different colors per memory.
 

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Tom,

The Optoma HD7100 has a full working saturation, tint and lightness adjustment per primary and secondary color. These adjustments are in the SM.

Despite all its adjustments, I do not seem to be able to get green to its theoretical x,y value in the gamut. Could this be a result of the grey screen I am using?

Any comments/suggestions?

Thanks a lot to you and all other contributors to this great thread.

Fermin
 

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Hi Tom,


Excellent write-up!!


And since I finally had a couple of free hours last night I decided to calibrate my Sharp Z12 using your exact procedure outlined above. For the most part everything worked great. I was able to adjust color and tint as you outlined, and only had to make minor adjustments to color bias and gain in order to get the tracking under dE of 3 across the board (except for 0 IRE, which I know is below the effective range of the EyeOne Pro). Then I finished up the color decoding by adjusting green and blue...so far so good.


The only problem I ran into with the Sharp was when it came to adjusting the gamut - Green was a problem, and because of the green problem, cyan is not right either. I was able to move all of the other colors so that they are right on the CIE targets, but green is undersaturated (if I am interpreting the chart correctly - green was originally outside the triangle, but lower than the green coordinate and way to the right), so I have no way to correct it (and cyan is undersaturated as well). Despite that little problem, I double checked everything else a second time and the color decoding is very, very good, as is the grayscale tracking.


My subjective impression is that most colors look absolutely dead accurate, though the greens looks a bit "pale". This might be because I know that green is not quite right, or it just may be due to viewing oversaturated greens for so long - I really don't know, but either way I am EXTREMELY happy with the results and the CMS functions of the Sharp. It was a real pleasure to have that much control over color!



Many thanks again!
 

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Discussion Starter #38
Bob:


This sounds like mainly a hue problem. First, put the green controls back to their default. Second, adjust green hue until the measured point falls on a line between the white point and the target green point. Finally, adjust green saturation (which will move the measured point closer to or further from the white point) until it falls on the target.


You should be able to adjust this out. I don't know what you mean when you say that "I have no way to correct it".
 

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Quote:
Originally Posted by anbjornk /forum/post/0


For EACH COLOR
. (Sorry, I was a bit short there) One can store up to eight different colors per memory.

That sounds like a color replacement system to me. You have to run the gamut tests to prove the entire gamut actually changes - not just one color.


A true color management system will do a 3x3 matrix transform to warp the gamut based on the editing of RGB parameters. Having a lookup table to remap a few colors is not at all the same thing.
 

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Thanks, Tom, I'll give that a try tomorrow night (my next opportunity).
Quote:
I don't know what you mean when you say that "I have no way to correct it".

Since I don't have a chart to post, I'll try my best to explain it. The green primary was initially located to the far right (like half way between green and red horizontally) and slightly lower (vertically) than the targeted primary. When I tried increasing saturation, there was no change in the reading at all, but when I lowered saturation the point dropped lower by quite a bit. When I tried adjusting hue in one direction I could move the point to the left, but the very left most I could get it was on a line between the green and red targets, which is where I left it. Cyan acted similarly in that it was inside the triangle initially, and no amount of change would allow me to place cyan on the line between green and blue - it was and is still inside of the triangle. These observations were confirmed visually as I watched the 75% green and cyan windows from the Accupel. Green looks "pale" for lack of a better term and I could not get it to look any "greener".


I started with 6500k as a starting point. Maybe I will try measuring a few other temperatures to see if there is a better starting point for calibration. I'll also double check to see if I did something stupid in feeding the signal from the Accupel to the 12K's DVI input, especially since you got better results than I did.


Thanks again for all of your help!
 
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