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Fixing the Oversaturation Problem in the JVC-RS1 - Page 7

post #181 of 303
O.k., I used HCFR and my Spyder 2 and discovered some interesting things. With the Spyder aimed at the projector, the grey scale was perfect on Middle and Gamma Normal. Facing my Optima Greywolf, I had accessive blue coming back. I went to User1 and quickly got a perfect greyscale on Gamma Normal facing the screen, with RGB levels of 99-100 across every IRE, and the Delta E was 0 or 1 from 40IRE to 100 (the Spyder is no good below 40). I put on some high def programming, and had the lobster faces again. Switched to Gamma C, and everything looked good. Checked the greyscale after the switch to Gamma C, and there was a big change. RBG levels for R/G/B were 93%,101,107% at 40IRE; 93, 101, 106 at 50 IRE; 94, 100, 106 at 60; 95, 100, 105 at 70; 96,100, 104 at 80; 96,100, 104 at 90, and 97,100, 103% at 100IRE, with Delta E of, 8,7,7,6,5,4,and 4. Average color temp also increased closer to 7K.

So switching to Gamma C reduces red in the greyscale, and makes the colors much more pleasant. I don't agree with people that say greyscale doesn't affect saturation. That is like saying painting red watercolors on white paper or pink paper will look the same.

Anyway, I think I can live with the image on Gamma C (which also reduced average gamma from around 2.12 down to 1.95.

Rick
post #182 of 303
Too tired to play much more, but I went back to Gamma Normal, User 1, where I have the dead perfect grey scale, and then used offset to reduce red. Faces looked VERY good. I will have to check greyscale again tomorrow with the offset setting to see if offset is changing the greyscale....
post #183 of 303
Quote:
Originally Posted by rdalcanto View Post

Too tired to play much more, but I went back to Gamma Normal, User 1, where I have the dead perfect grey scale, and then used offset to reduce red. Faces looked VERY good. I will have to check greyscale again tomorrow with the offset setting to see if offset is changing the greyscale....

I'd like to hear what this did to grayscale, as I have also used the offset to reduce red.
post #184 of 303
Quote:


So switching to Gamma C reduces red in the greyscale, and makes the colors much more pleasant. I don't agree with people that say greyscale doesn't affect saturation.

You are attempting to mask one inaccuracy by creating another. You CAN make the image's red appear less pronounced by inducing a red-deficient gray scale, just like you CAN just turn down the Color control thereby making the red less intense. In both cases you are making the image worse, not better.

The only way to fix this problem is with a dedicated saturation adjustment found in a properly-designed CMS.
post #185 of 303
Quote:
Originally Posted by rdalcanto View Post

If colors can be accurate on a $1000 projector, why can't they be accurate on a $6K projector? I can understand needing an external processor to stretch the image, but for acceptable color.... ?!?

Many LCDs have a gamut that exceeds the system gamut, and this is why they have been described as almost fluorescent by some people in the past, so it's nothing new with that kind of technology.

I've a feeling advertising a gamut that is greater than the standard is probably more of a marketing gimmick for the masses rather than for those who want accuracy.

I saw one of the first HD1s here in the UK and it looked fine - it had been calibrated by a very knowledgeable and experienced calibrator over here, so that's why it looked so good without a noticeable over saturation problem. I recently saw one of the newer production models, and with only a little tweaking of the colour control and running at pretty much out of the box settings, that also looked reasonably natural with no obvious issues.

Gary
post #186 of 303
Quote:
Originally Posted by Otto J View Post

... The reason that color saturation decreases as you decrease the "color" control (intensity), is that you are moving up the Z axis, and the CIE diagram isn't built to show changes in Z axis. Now, on a linear 3-dimensional diagram, that wouldn't make a difference, but light isn't' linear - the Z axis isn't just adding a linear third dimension. At near black, the diagram wouldn't be the same size as the CIE - think of black as a spot, and then the range increases outwards until you reach the max saturation possible, which is where the CIE diagram is "cut out", and then as the intensity increases, the range decreases again, until at some point VERY far out, it becomes a spot again. Because of this, when you decrease intensity, you go "down" the Z axis, but not in a straight line downwards - as you go down, you will move inwards towards the middle as well, because of the shape of the color range described above. Basically, you can't decrease intensity without affecting saturation, but you CAN decrease saturation without affecting intensity...



I found a diagram of a 3D color tree that helps to visualize what Otto is describing.

post #187 of 303
That's a very nice way to visualize it. BTW, "Value" in the image is what we've been calling "Intensity."
post #188 of 303
Quote:
Originally Posted by TomHuffman View Post

That's a very nice way to visualize it. BTW, "Value" in the image is what we've been calling "Intensity."

Are the terms value and intensity synonymous with "lightness"?
post #189 of 303
This would imply that turning down the color control will give you black. This is how the "Perfect Color" BS on the Mitsubishi sets works. Are you saying that the RS1 works the same way?
post #190 of 303
Quote:
Originally Posted by Rob Tomlin View Post

Are the terms value and intensity synonymous with "lightness"?

"lightness" being what Greg was talking about in his WSR review?
post #191 of 303
"This would imply that turning down the color control will give you black. "

To me it implies gray - it moves inward but stays at the same luminance level.
post #192 of 303
Thread Starter 
DIYGuy: Thanks so much for that incredible diagram. I finally understand what we are talking about here!!!!!
post #193 of 303
Quote:
Originally Posted by Forceflow View Post

"lightness" being what Greg was talking about in his WSR review?

Yes.
post #194 of 303
Quote:
Originally Posted by Rob Tomlin View Post

Are the terms value and intensity synonymous with "lightness"?

Yes.
post #195 of 303
Quote:
Originally Posted by Harry Brandt View Post

DIYGuy: Thanks so much for that incredible diagram. I finally understand what we are talking about here!!!!!

I concur. All of the factors are represented in that amazing diagram. We need AVS awards to give people like you and Tom. Now I need to reread Greg's WSR review...
post #196 of 303
Thanks for the confirmation Tom. Makes sense.
post #197 of 303
All of the below represents my prior understanding of the color saturation/intensity relationship. It is most certainly wrong and posted to see if parts are correct.

Should the diagram with colors be more diamond/almond shaped.

Color saturation is tied to intensity and by moving intensity down or up from the point of highest saturation (which is the cross section of the CIE chart?) you move the saturation in. If you move far enough down the intensity scale, saturation and lightness move to zero and the result is black. Move up the intensity scale all the way and you have white. Is this correct?

The RS-1's color control moves the color along the lightness axis which reduces saturation at the same time. If it had a proper saturation control, it would bring the primaries in closer to the gray scale axis as opposed to moving the saturation by changes in intensity.
post #198 of 303
Thread Starter 
This is off-topic, but if anybody is interested....i found the website where that color tree diagram is from...and there is an excellent tutorial on color:

http://www.art-head-start.com/color-wheel.html


Harry
post #199 of 303
Quote:


If you move far enough down the intensity scale, saturation and lightness move to zero and the result is black. Move up the intensity scale all the way and you have white.

Not quite. In principle, if the intensity were zero, then, yes, it would be black. The Color control has only a limited range of adjustment, so even at its minimum setting you don't get black. Also, if you maxed out the color control (color intensity), you wouldn't get white. You would get really, really bright colors. You get white by reducing the saturation to zero.

What a properly designed CMS will allow you to do is adjust the saturation/hue of a color without affecting its intensity, at least within a reasonable range of adjustment. The better ones also allow you to adjust the intensity of each of the colors individually, instead of globally, which is what the Color control does.
post #200 of 303
Tom quick question on this.

If the primaries and secondaries were all, but not equally oversaturated, if instead of using the main color control first, you adjusted each individual primary and secondary using the CMS until all the x & y's values were within a delta of 1 from their CIE ref, is there any downside to doing it this way ?
post #201 of 303
Quote:
Originally Posted by Joe_Black View Post

If the primaries and secondaries were all, but not equally oversaturated, if instead of using the main color control first, you adjusted each individual primary and secondary using the CMS until all the x & y's values were within a delta of 1 from their CIE ref, is there any downside to doing it this way ?

If the problem is oversaturated primaries and secondaries, you shouldn't use the main color control at all. Otherwise, yes, that's exactly what you would do.
post #202 of 303
Quote:
Originally Posted by TomHuffman View Post

If the problem is oversaturated primaries and secondaries, you shouldn't use the main color control at all. Otherwise, yes, that's exactly what you would do.

Thanks Tom !
post #203 of 303
VERY INTERESTING!!!!!!!!!!!!!

First, decreasing offset of red to -15, directly affected the greyscale, and lowered it from 99% to 90-92%, depending on IRE. The advantage to using that over gamma C, is that blue and green stay more constant.

HOWEVER, even MORE interesting, was the simple test I did with my DVR. I switched from Component, where the faces were WAY too red when the offset was zero, gamma Normal, to HDMI and THERE WAS SUDDENLY NO OVERSATURATION PROBLEM!!!!!!!!!!!! I don't know if the problem is with the component on the cable box, or the component processing on the projector, but problem solved with HDMI.

Rick

EDIT: This is the problem with writing too late at night. The problem can't be me cable box because my AE900U was also connected via component with no oversaturation problem. Therefore I'm convinced the problem is with the RS1 and the way it handles component input. Hopefully JVC will do a firmware fix, so that component has the same neutral colors of HDMI.
post #204 of 303
Quote:
Originally Posted by rdalcanto View Post

VERY INTERESTING!!!!!!!!!!!!!

First, decreasing offset of red to -15, directly affected the greyscale, and lowered it from 99% to 90-92%, depending on IRE. The advantage to using that over gamma C, is that blue and green stay more constant.

HOWEVER, even MORE interesting, was the simple test I did with my DVR. I switched from Component, where the faces were WAY too red when the offset was zero, gamma Normal, to HDMI and THERE WAS SUDDENLY NO OVERSATURATION PROBLEM!!!!!!!!!!!! I don't know if the problem is with the component on the cable box, or the component processing on the projector, but problem solved with HDMI.

Rick

EDIT: This is the problem with writing too late at night. The problem can't be me cable box because my AE900U was also connected via component with no oversaturation problem. Therefore I'm convinced the problem is with the RS1 and the way it handles component input. Hopefully JVC will do a firmware fix, so that component has the same neutral colors of HDMI.

So you're saying that in your experience, it is the component input that has over-saturation? HDMI is ok? Or are you saying there is over-saturation on both inputs but the HDMI is better?

Is anybody else experiencing this difference between component and HDMI inputs?
post #205 of 303
I think if you look at the primaries with a colorimeter, they are slightly oversaturated even with HDMI, but that is so subtle that I don't notice it at all over HDMI. It turns out that others have reported the same aweful oversaturation with component as well. You can either turn color way down, or just use HDMI.

I love the projector now. Without a DI like other projectors, mixed images are so bright, it actually hurts my eyes. I also will have to darken my walls now....
post #206 of 303
I spent a bit of time with component before going to hdmi , calibrated both inputs , didn't find a vast difference between the two . You need to adjust for each input and save seperate profiles for each ..and then remember to select the correct profile. That said the differences between the two were not massive.
post #207 of 303
Quote:
Originally Posted by Harry Brandt View Post

For what it's worth, I think many would love this projector (with the gamma on "C" and color dialed down a bit) WITHOUT a VP or ISF calibration.

That doesn't make any sense. You decrease (color)intensity by lowering "color" and changing gamma to "C" will then increase the intensity of the image.

Choosing gamma "C" not only gives you a gamma that is lower than the videostandards (about 2.0, where the standards are defined as "2.2, minus 0.0 plus 0.6") but above all it will give you a very flat image that lacks contrast. Really, "Normal" gamma (about 2.2, its sad that the pj cant go higher) is the only gamma I would choose. Yes, lowering gamma reduces colorsaturation a bit but it simply isn't a god way to do it.
post #208 of 303
Quote:
Originally Posted by my_pacman View Post

That doesn't make any sense. You decrease (color)intensity by lowering "color" and changing gamma to "C" will then increase the intensity of the image.

Choosing gamma "C" not only gives you a gamma that is lower than the videostandards (about 2.0, where the standards are defined as "2.2, minus 0.0 plus 0.6") but above all it will give you a very flat image that lacks contrast. Really, "Normal" gamma (about 2.2, its sad that the pj cant go higher) is the only gamma I would choose. Yes, lowering gamma reduces colorsaturation a bit but it simply isn't a god way to do it.

I agree. I played with Gamma "C" and lowered brightness a little, but it doesn't have the same punch as "normal". I have no complaints as far as the saturation of the colors.
post #209 of 303
Thread Starter 
Quote:
Originally Posted by Alex512 View Post

I agree. I played with Gamma "C" and lowered brightness a little, but it doesn't have the same punch as "normal". I have no complaints as far as the saturation of the colors.

Good example of variability in tastes. Some want "punch".....some want "accuracy".

My guess is that across the general public...more people want "punch"....just as in audio where people tend to enjoy exaggerated mid-bass and bass.
post #210 of 303
Thread Starter 
Quote:
Originally Posted by my_pacman View Post

That doesn't make any sense. You decrease (color)intensity by lowering "color" and changing gamma to "C" will then increase the intensity of the image.

Choosing gamma "C" not only gives you a gamma that is lower than the videostandards (about 2.0, where the standards are defined as "2.2, minus 0.0 plus 0.6") but above all it will give you a very flat image that lacks contrast. Really, "Normal" gamma (about 2.2, its sad that the pj cant go higher) is the only gamma I would choose. Yes, lowering gamma reduces colorsaturation a bit but it simply isn't a god way to do it.

I can only tell you what i'm observing at this point...and we'll see what happens after ISF calibration on April 28th......but on gamma c...with the color reduced to about -10...i'm seeing more normal flesh tones.

I'll take another look at "normal" gamma tonight....but from recollection it did not appear realistic.
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