The VideoEq -- A low cost external grayscale/gamma/cms tool - Page 24 - AVS Forum
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Old 12-30-2010, 07:45 AM
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I have been wondering about the 8 bit versus 10 bit matter myself. Hopefully someone very familiar with the product can clear this up.
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Old 12-30-2010, 11:01 AM
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Originally Posted by lovingdvd View Post
I have been wondering about the 8 bit versus 10 bit matter myself. Hopefully someone very familiar with the product can clear this up.
Don't seem to be getting much feedback at all from the manufacturers as questions on the Calman forum seem to sit unanswered for ages. I'm actually quite disappointed with the whole experience of the VEQ, from being a supposed beta tester, to the lack of response at various times (not just around Christmas). It's mainly through online discussions and taking time to work out how best to use it that I've been able to end up with a good calibration result. Some have been asking for measurements at different saturations to check linearity, but if it turns out that it's no better than the JVC CMS then that would be the final insult.

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Old 12-30-2010, 12:54 PM
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using force 10bit should give slightly better quality with a real 10bit display.

Granted you still have an 8bit source, so you can't do better than the 255 steps available in the initial source( 219 in video range). But an 8bit in 8bit out you'll have fewer than 255 steps available because because you'll have some levels that are skipped and some levels that are duplicated. With 8bit in and 10bit out, you'll likely maintain 255 steps in all but the most extreme LUTs.

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Old 12-30-2010, 03:16 PM
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Quote:
Originally Posted by leDahu View Post

The hd-750 upgraded CMS is not linear when we look into the detail, mainly in the range 75-100%. See the attached files. They are a sort of CMS signature.

It is not a single case: Htnut2000 and other members measured the same trend
http://www.avsforum.com/avs-vb/showt...9#post19644859

Would you accept to carry out the same measurement on the VideoEQ with HCFR and 40 saturation color levels?

Also, measuring primaries and secondaries at 25,50,75 and 100% stimuli would complete the test.

I guess everybody would encourage any Lumagen/Duo owner to conduct the same test.

Thanks

Understand that the VideoEQ Pro provides a single point of adjustment for each of the primary and secondary colors. At that point, you can adjust saturation, hue, and luminance for that color. You are going to select the level (100%, 75%, or other level of your choice) within your calibration software and adjust the VEQ to meet those targets. Now, because you are adjusting only a single reference point and not a range of points (as you do for grayscale) for each color, I'd think that non-linearities in color saturation/luminance would have to be laid at the feet of the display itself. And this isn't a new problem. I mean, almost 10 years ago we Mitsubishi CRT RPTV owners knew that if we aligned our color decoders at 100% they wouldn't be as accurate at 75%, and vice-versa.

Perhaps the only real way to compare these different CMS systems is side-by-side on the same display. That way any non-linearities in the display would hopefully equally affect all results.

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Old 12-31-2010, 09:09 AM
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Quote:
Originally Posted by sotti View Post

using force 10bit should give slightly better quality with a real 10bit display.

Granted you still have an 8bit source, so you can't do better than the 255 steps available in the initial source( 219 in video range). But an 8bit in 8bit out you'll have fewer than 255 steps available because because you'll have some levels that are skipped and some levels that are duplicated. With 8bit in and 10bit out, you'll likely maintain 255 steps in all but the most extreme LUTs.

Thank you very much for your fast and intelligible answer.

I have a third question: does the VideoEQ process the 3D signal the same way as for 2D and not just as total or partial pass through?
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Old 12-31-2010, 11:04 AM
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Quote:
Originally Posted by leDahu View Post

Thank you very much for your fast and intelligible answer.

I have a third question: does the VideoEQ process the 3D signal the same way as for 2D and not just as total or partial pass through?

yes the video EQ doesn't use a frame buffer, so weather the content is alternating frame, side by side or top and bottom the videoEQ applies the same processing to content for the left and right eye.

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Old 01-01-2011, 04:04 PM
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Thanks Sotti
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Old 02-14-2011, 09:22 AM
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Originally Posted by lovingdvd View Post

In the thread I linked to there is much discussion about the built in CMS in the JVC RS projectors. Some people are speculating that the CMS in external processors such as the VideoEQ Pro, Lumagen, and Duo do a better job when it comes to saturation and linearity.

The primary difference between the RS40 and RS50 is the CMS that is built into the RS50. If it does turn out that the RS40 + VideoEQ produces equally or better results than the RS50 with its built-in CMS, then that will mean some (many?) people will buy the RS40 and an external processor such as the VideoEQ instead of the RS50 (better results while saving money).

There is question as to which of these three external CMS does the best job and how they all compare. For example if the VideoEQ can do an equally as good job as the Lumangen Radiance then money can be saved by those who only want CMS functions by going with the VideoEQ. What we lack right now is a real comparison between how the CMS results compare. If you read through the thread I linked to you will see the types of tests we are looking for. So far we do not have any results from the VideoEQ.

I dont think we will be able to read about this comparison because of politics. Unless either a bunch of you owners get together and pull this off or some rich guy buys all the products and does it.

So until it happens , ill pray every day i get a chance to read a true comparison of the Video EQ , Lumangen Radiance , or DVD Duo by one of you videophiles instead of a magazine.

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Old 02-14-2011, 10:23 AM
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Originally Posted by baddgsx View Post

I dont think we will be able to read about this comparison because of politics. Unless either a bunch of you owners get together and pull this off or some rich guy buys all the products and does it.

So until it happens , ill pray every day i get a chance to read a true comparison of the Video EQ , Lumangen Radiance , or DVD Duo by one of you videophiles instead of a magazine.

I may well be able to do something like this as a research project once I get saturation and luminance sweeps in. I've already got all the hardware laying around.

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Old 02-14-2011, 11:35 AM
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I may be able to compare the VideoEQ Pro to my new Radiance Mini3D before I sell the VEQ. However I only have a 'profiled' i1LT at the moment, but hopefully this will be of some use as it's comparing the same display, but with two different CMS units. Hiowever, I'm more interested in setting up the new toy and making sure I'm happy with it so I can sell on the VEQ, but I'll try to do the test.

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Old 02-15-2011, 09:17 AM
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Take this one step further. I have the VideoEQ pro. IF once I use Calman 3.7 and then load HCFR, CalMan, or ChromaPure. Wouldn't the results be the same?

Once I used one, then all the rest should show the same results and be within tolerance that you couldn't see the difference.

Wouldn't the same analogy apply to either an external CMS or built in CMS. After all your using HCFR, CalMan, or ChromaPure to adjust and measure them to the same end results.
(really comes down to ease of use I figure)
Is the question really about how you get there?

Hope this made sense.
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Old 02-15-2011, 10:08 AM
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Hagar, what we are interested in comparing is the linearity of the CMS: The VideEQ and Radiance have (currently) only a single point adjustment for the CMS. Therefore it is possible that at different saturations the measured results (using either Calman, HFCR or Chromapure) could be different for each CMS solution at points other than those that the calibration was done. When I calibrated with my VideoEQ I used 75% patterns, for example. It could be that there is an error at 100% or 50% and it may vary dependinig on which CMS you use (even if the 75% calibration measures exactly the same with either CMS).

I plan to use the Mini3D for greyscale, gamma and CMS into my HD350. I could then copy this setting to a spare memory and clear the CMS. I would then add my VideoEQ into the chain and only adjust the CMS settings (so both results use the same greyscale correction, which I would also check with the VEQ in and out of circuit for consistancy). As Lumagen recommend calibrating the CMS at 100% I would also set the VideoEQ using the same 100% patterns for consistancy.

If anyone has any further comments regarding this methodogy please let me know as I plan to recalibrate my projector tomorrow night, so I might be able to perform these checks then or on Thursday night (OH out of town ).

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Old 02-16-2011, 10:46 PM
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Quote:
Originally Posted by Kelvin1965S View Post

Hagar, what we are interested in comparing is the linearity of the CMS: The VideEQ and Radiance have (currently) only a single point adjustment for the CMS. Therefore it is possible that at different saturations the measured results (using either Calman, HFCR or Chromapure) could be different for each CMS solution at points other than those that the calibration was done. When I calibrated with my VideoEQ I used 75% patterns, for example. It could be that there is an error at 100% or 50% and it may vary dependinig on which CMS you use (even if the 75% calibration measures exactly the same with either CMS).

I plan to use the Mini3D for greyscale, gamma and CMS into my HD350. I could then copy this setting to a spare memory and clear the CMS. I would then add my VideoEQ into the chain and only adjust the CMS settings (so both results use the same greyscale correction, which I would also check with the VEQ in and out of circuit for consistancy). As Lumagen recommend calibrating the CMS at 100% I would also set the VideoEQ using the same 100% patterns for consistancy.

If anyone has any further comments regarding this methodogy please let me know as I plan to recalibrate my projector tomorrow night, so I might be able to perform these checks then or on Thursday night (OH out of town ).

Kelvin,

I checked the linearity of the VideoEQ Pro some time ago and it was spot on. I tested in on a Pioneer 8G Kuro that is known to have a problem with linearity using Colour Space 2. Sure enuf, in Colour Space 2 there were linearity issues with or without the VEQ Pro (in colour space 2, the colour points are already close to rec 709 colour space so not much change in VEQ Pro is needed). I was also told that Colour Space 1 did not have linearity issues but it is a wide gamut colour space. I verified this with and without the VEQ Pro as well. Since the Kuro does not have a full CMS the only option is to use Colour Space 1 and a external CMS. What I did then was to calibrate the colours to rec 709 colour space using the VEQ Pro in colour space 1 on the Kuro and checked for linearity after pulling in the colours correctly and there were no linearity issues even with the changes in the VEQ Pro. I will have to find the reports or redo it as since then I have taken the VEQ Pro out of the chain and am planning on using it on my 9G Kuro for further accuracy.

So based on what I have seen and experienced the VEQ Pro does not seem to have linearity issues as long as the mode/display is linear to start with. Even pulling in the saturations to quite extreme , ie from wide gamut to rec 709 and making big adjustments on the luminance does not induce non linearity on the VEQ Pro.
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Old 02-17-2011, 09:00 AM
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Originally Posted by venkatesh_m View Post

Kelvin,

I checked the linearity of the VideoEQ Pro some time ago and it was spot on. I tested in on a Pioneer 8G Kuro that is known to have a problem with linearity using Colour Space 2. Sure enuf, in Colour Space 2 there were linearity issues with or without the VEQ Pro (in colour space 2, the colour points are already close to rec 709 colour space so not much change in VEQ Pro is needed). I was also told that Colour Space 1 did not have linearity issues but it is a wide gamut colour space. I verified this with and without the VEQ Pro as well. Since the Kuro does not have a full CMS the only option is to use Colour Space 1 and a external CMS. What I did then was to calibrate the colours to rec 709 colour space using the VEQ Pro in colour space 1 on the Kuro and checked for linearity after pulling in the colours correctly and there were no linearity issues even with the changes in the VEQ Pro. I will have to find the reports or redo it as since then I have taken the VEQ Pro out of the chain and am planning on using it on my 9G Kuro for further accuracy.

So based on what I have seen and experienced the VEQ Pro does not seem to have linearity issues as long as the mode/display is linear to start with. Even pulling in the saturations to quite extreme , ie from wide gamut to rec 709 and making big adjustments on the luminance does not induce non linearity on the VEQ Pro.

Im still rocking the Pioneer 141 and i think your statement convinced me to get a Video EQ PRO. If any one has one that they want to get rid of let me know. the last one on videogon sold quicker than i could make my decision.

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Old 02-17-2011, 02:38 PM - Thread Starter
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Quote:
Originally Posted by venkatesh_m View Post

So based on what I have seen and experienced the VEQ Pro does not seem to have linearity issues as long as the mode/display is linear to start with.

I believe that's the real issue, even if not clearly articulated by the OP. Not if a VEq or Radiance is linear but the fact that a non-linear display needs multiple points of adjustment.

If the mini Radiance can do that then it's clearly ahead of the game.
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Old 02-17-2011, 07:29 PM
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Originally Posted by baddgsx View Post

Im still rocking the Pioneer 141 and i think your statement convinced me to get a Video EQ PRO. If any one has one that they want to get rid of let me know. the last one on videogon sold quicker than i could make my decision.

In all honesty, the 9G Kuros are pretty accurate for almost all colours except blue. Even then, the DE1994 for the the colours were below 1.5 for all except blue (~2.9) and red (2). So while using the VEQ Pro with my 9G can make all DE1994s close to or below 1.5, I could not really see the difference that much. I did it just becoz the 9G is my main display and thought why not make it as accurate as I can.

Using the VEQ Pro on the 9G Kuro, I started with Colour Space 1 that was wide gamut and pulled all in. I got better DEs for Luminances, Saturation and Hues for all colours except Blue.

Will try to do some charts when I find the time.
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Old 02-17-2011, 07:31 PM
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Originally Posted by bodosom View Post

I believe that's the real issue, even if not clearly articulated by the OP. Not if a VEq or Radiance is linear but the fact that a non-linear display needs multiple points of adjustment.

If the mini Radiance can do that then it's clearly ahead of the game.

I did not know that the mini Radiance could make adjustments at different % stimuli. If it does, yeah, its a great tool for displays that are non linear.
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Old 06-15-2011, 12:43 PM
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Originally Posted by baddgsx View Post

I dont think we will be able to read about this comparison because of politics. Unless either a bunch of you owners get together and pull this off or some rich guy buys all the products and does it.

So until it happens , ill pray every day i get a chance to read a true comparison of the Video EQ , Lumangen Radiance , or DVD Duo by one of you videophiles instead of a magazine.

Lets re-visit this - I have the VideoEQ pro which I think they stopped marketing.

But in thinking of getting a RS40/X3 and 3d, the VideoEQ is 1.3 hdmi compliant. How will this effect 3d? (and why do they say the VEQ is 3D?)The Lumagen RadianceMini 3D is 1.4.

And whats the advantage of one over the other if you don't mind. Seems the VideoEQ is falling out of favor.

Dave
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Old 06-15-2011, 01:16 PM
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The videoEQ isn't a full 1.4 device, but it does support passing the requisite headers for 3d, and can apply it's calibration tables to a 3d stream.

The pros of the videoEQ is that is cheaper and does an equally good job of calibrating the video signal (and in this case you own it).

The radiance is more expensive, but has two inputs and a host of video processing capabilities.

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Old 03-23-2014, 08:07 PM
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Ah to revive an old thread, does the heart good.

Been working with my OCD with Ray in CA about being obsessive in calibrating.

I seem to calibrate to the 9th degree and then some thinking its not good enough to be under 3 delta, but its got to be under 1.

I had a question about my RS25 and the GAMMA portion in the CMS and didn't understand why it stopped at 95%? The Video EQ goes to 100. Anyone?

Now throwing another question out about WHY if using the Video EQ instead, why do I need to use above 100 to get say BLUE saturation in line? But its causing my display to overdrive and cause some conflict. (like turn to red)eek.gif

So is it possible to to overdrive using the internal RS25 CMS I wonder too?

I got the following from AVFoundry Eric L Herns who knows way to much.

I'm quite sure there is nothing wrong with the VideoEq. The failures we've seen are basically all or none. If it makes a picture, then it's good. If there is a problem, then there is no picture.

There are a lot of subtleties to the way the calibration coefficients are calculated and used by the processing blocks. I highly doubt any two CMS implementations are the same, even if they have the same controls.

In general, it's a bad idea to set either the saturation or brightness above 100. You're going to drive something into over saturation or clipping at some point. If you think about it as a multiplier - sending a full white signal at 255 (8-bit level) with a multiplier of 117% would result in 298, which doesn't fit in 8-bits anymore.

One thing to be very careful of here is that you run plenty of high level content through it before you are done calibrating. I've heard (and seen) some calibrations that are really good by the numbers in CalMAN, and make a nice picture on most content. But then during something like an explosion scene, where the picture level is high, the whole thing clips and gives green/red flashes. Sometimes it's just "sparklies" around the bright edges. What happens is that these bright pixels go beyond the 8 or 10 bit limit and cause problems.

Some implementations will "clamp" the value so that anything >255 is limited to 255. Others could wrap so that 298 results in 42. The first method of clamping fails more gracefully as over-saturation just quietly turns to pure white. It's been a long time since we worked on that part of the Eq, so I can't really remember which it uses.

Also, since the CMS works as a linear function, there is some interdependence between the controls. Meaning you might be able to increase saturation to say 120 if you reduce luminance by 5 or so.

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Old 03-23-2014, 09:00 PM
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I think JVC's thoughts behind only going up to 95% in the custom gamma is that 100% will be set with the contrast and white balance gains/drives, and then it is what it is and serves as the reference point for all the lower intervals. Is that what you're talking about?

BTW, my videoEQ is super slow, whether being controlled by CalMAN or it's own web interface. It's much slower updating and sending the commands than any other DDC device I've used, including ones with serial interfaces. Is this normal?

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Old 03-25-2014, 11:26 AM
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You want to talk slow, I give you my colormunki for the winner in thsi contest. Sloowwwww.

Thanks for the reply on the 95% rs 25 gamma limit.

I am blown away nobody posted pictures and or this has not been mentioned. But I guess using a Video EQ that has 100 as the top level reference, I was expecting that in the RS25 as well.

Now if I get a hold of the demon regarding blue.

AV Foundry says you should NOT go above 100 saturation. What if you do.?

In the RS25, is "0" 100 or the high end +50?

Do color temps affect this?
I'm gonna find out today when I recalibrate taking out the VideoEQ and see what I get.

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Old 04-07-2014, 08:20 PM
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Anyone else driving or having to drive their Video EQ saturation and or brightness or both in the CMS beyond 100 to get a calibrated picture?

Eric at AV Foundry doesn't recommend it,

In general, it's a bad idea to set either the saturation or brightness above 100. You're going to drive something into over saturation or clipping at some point. If you think about it as a multiplier - sending a full white signal at 255 (8-bit level) with a multiplier of 117% would result in 298, which doesn't fit in 8-bits anymore.

One thing to be very careful of here is that you run plenty of high level content through it before you are done calibrating. I've heard (and seen) some calibrations that are really good by the numbers in CalMAN, and make a nice picture on most content. But then during something like an explosion scene, where the picture level is high, the whole thing clips and gives green/red flashes. Sometimes it's just "sparklies" around the bright edges. What happens is that these bright pixels go beyond the 8 or 10 bit limit and cause problems.

Some implementations will "clamp" the value so that anything >255 is limited to 255. Others could wrap so that 298 results in 42. The first method of clamping fails more gracefully as over-saturation just quietly turns to pure white. It's been a long time since we worked on that part of the Eq, so I can't really remember which it uses.

Also, since the CMS works as a linear function, there is some interdependence between the controls. Meaning you might be able to increase saturation to say 120 if you reduce luminance by 5 or so.


But why then do we have the option to go beyond 100 and stretch it out from 0-200 then?

Seems in low lamp I don't have enough brightness?
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Old 04-08-2014, 12:39 PM
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Quote:
Originally Posted by Hagar View Post

Anyone else driving or having to drive their Video EQ saturation and or brightness or both in the CMS beyond 100 to get a calibrated picture?

Eric at AV Foundry doesn't recommend it,

In general, it's a bad idea to set either the saturation or brightness above 100. You're going to drive something into over saturation or clipping at some point. If you think about it as a multiplier - sending a full white signal at 255 (8-bit level) with a multiplier of 117% would result in 298, which doesn't fit in 8-bits anymore.

One thing to be very careful of here is that you run plenty of high level content through it before you are done calibrating. I've heard (and seen) some calibrations that are really good by the numbers in CalMAN, and make a nice picture on most content. But then during something like an explosion scene, where the picture level is high, the whole thing clips and gives green/red flashes. Sometimes it's just "sparklies" around the bright edges. What happens is that these bright pixels go beyond the 8 or 10 bit limit and cause problems.

Some implementations will "clamp" the value so that anything >255 is limited to 255. Others could wrap so that 298 results in 42. The first method of clamping fails more gracefully as over-saturation just quietly turns to pure white. It's been a long time since we worked on that part of the Eq, so I can't really remember which it uses.

Also, since the CMS works as a linear function, there is some interdependence between the controls. Meaning you might be able to increase saturation to say 120 if you reduce luminance by 5 or so.


But why then do we have the option to go beyond 100 and stretch it out from 0-200 then?

Seems in low lamp I don't have enough brightness?

As a long-time VideoEQ Pro owner, I agree with Eric. If selecting a saturation over 100%, you are trying to force the display to do something it in most cases cannot do. If you need to boost saturation, try doing it by increasing the display's Color control. You'll also bring up Luminance, but that can be reduced with the VideoEQ. In fact, the VideoEQ and other CMS/grayscale boxes work better when cutting rather than boosting the signal. Eric mentioned sparklies, and you can get some other weird results such as cyan or magenta highlights from those bright pixels. When calibrating my VideoEQ, I first set brightness and contrast and the set's white balance to D65 at 109% White using a test disc, with the VEQ set to preset 1 (unity). I found that setting the display's white point at 109% helped eliminate the sparklies and cyan/magenta highlights. It may reduce the maximum light output a bit, but to me that's better than having the highlight issues.

Another option is to set up custom color targets in CalMAN using your pj's primaries as they are. You'll still be able to have a D65 whitepoint. And I'm willing to bet you wouldn't be able to see much of a difference, if any, between images rendered with a custom color target and those rendered with Rec 709, for example.

...Royce...

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