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post #121 of 162 Old 09-08-2011, 05:00 AM - Thread Starter
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Folks may wish to check out Poynton’s vectors to see his views on the consumer gamma calibrations http://www.spectracal.com/documents/...tor%201-12.pdf

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Originally Posted by Poynton'sVectors
If the power function on R’G’B’ – display gamma – is dialed back a little, that contrast and colorfulness are reduced. At about 300 nt,with ambient illuminance of 5 or 10 lx, and with a surround of say 5%,decreasing gamma from 2.4 to 2.2 will visually compensate the effect.So, if your consumer has such an environment, I recommend gammaof 2.2. If your customer preferred to display the same imagery at48 nt, in darkness (zero ambient illuminance), in a 0% surround, then gamma of 2.6 (as in digital cinema) might be appropriate. In a really,really bright environment, or with a really bright display (say 400 nt or500 nt), decreasing gamma to 2.0 might be appropriate.
For his views on gamma issues see http://www.poynton.com/notes/colour_...mma_correction
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post #122 of 162 Old 09-08-2011, 05:10 AM
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Originally Posted by gregr View Post
I don't find the differences between a gamma of 2.2 and 2.4 to be subtle in the least, and in fact I consider a gamma of 2.4 to be nearly mandatory to obtain good picture quality in a front projection system.
Not that it matters, but this has been my experience on my digital projectors too. If the higher gammas always result in significantly more "vibrant" shall we say, images. Unfortunately I usually have to go back to something like 2.2 lest black is crushed horribly. I'm not actually sure what I've got my Planar set at now though.

See what an anamorphoscopic lens can do, see movies the way they were meant to be seen
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post #123 of 162 Old 09-08-2011, 05:18 AM
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Originally Posted by HoustonHoyaFan View Post
Folks may wish to check out Poynton’s vectors to see his views on the consumer gamma calibrations
Sounds just like what I've been saying:
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The intended appearance for an HD master is obtained through a 2.4-power function, to a display having reference white at 100 nt, with 1 lx ambient, and 1% surround – but that appearance will not be faithfully presented in different conditions!
The only difference, is that I have recently switched to 48nt on my display as I find 100nt can be fatiguing when watching a couple of films in a row late at night in a dark room.

I have not found it necessary to increase gamma to compensate for this; I've yet to find any consumer display that looks good going much over 2.4 gamma. DCI uses a higher gamma because the entire display chain was designed around it. Anything consumer-grade (or intended for consumer use) should be running 2.4
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post #124 of 162 Old 09-08-2011, 10:32 AM
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Quote:
Originally Posted by Chronoptimist View Post

It all levels from 16 upwards are visible and distinct from one another, you are displaying all the shadow detail in the source.

It is not going to be as distinct on a lower contrast display, but if it is visible and the individual steps do not blend together, then you are not losing shadow detail.

I think there's a bit of a disconnect here because "loss" is ambiguous; it can mean completely gone, or just lessened.

Without black level gamma compensation some shadow detail will be lost in the first meaning.

With it, it can be recovered, but detail is still lost - lessened (less visible because of lower contrast), which is clearly what Greg means.

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post #125 of 162 Old 09-08-2011, 11:13 AM
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Originally Posted by noah katz View Post

I think there's a bit of a disconnect here because "loss" is ambiguous; it can mean completely gone, or just lessened.

Without black level gamma compensation some shadow detail will be lost in the first meaning.

With it, it can be recovered, but detail is still lost - lessened (less visible because of lower contrast), which is clearly what Greg means.

if every step from 16-255 is visible, no shadow detail has been lost.

It is visible, but lower contrast. That is all.
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post #126 of 162 Old 09-08-2011, 01:13 PM
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Originally Posted by Chronoptimist View Post

It all levels from 16 upwards are visible and distinct from one another, you are displaying all the shadow detail in the source.

It is not going to be as distinct on a lower contrast display, but if it is visible and the individual steps do not blend together, then you are not losing shadow detail. That is precisely what black level compensation does. It adjusts the curve so that all values lie above black.

That is simply ridiculous. It's like saying if you can see any differentiation between adjacent black and white pixels then you are not losing any display resolution. It is the contrast between those black and white pixels that matters when trying to resolve high frequency detail.

When it comes to shadow detail it is again the contrast between the dark signal levels (and between the dark signal levels and the black background) that determines what degree of shadow detail you see. Unless black has zero luminance you lose some shadow detail. Raising the luminance of dark signal levels further above black improves the shadow detail differentiation between those details and a black background (eventually at the expense of contrast between signal levels), but can't possibly achieve the same shadow detail as lowering the black level to zero.

Also note that if you actually set the black level control to 16 on the display (which means the display outputs its lowest possible lumens at level 16 but not at any higher digital value) then all dark levels starting at 17 will already be above black. So by your definition you don't lose any shadow detail on any calibrated display and you don't need any "black level gamma compensation".

Enough of this nonsense.

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post #127 of 162 Old 09-08-2011, 01:50 PM
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Originally Posted by gregr View Post

That is simply ridiculous. It's like saying if you can see any differentiation between adjacent black and white pixels then you are not losing any display resolution. It is the contrast between those black and white pixels that matters when trying to resolve high frequency detail.

When it comes to shadow detail it is again the contrast between the dark signal levels (and between the dark signal levels and the black background) that determines what degree of shadow detail you see. Unless black has zero luminance you lose some shadow detail. Raising the luminance of dark signal levels further above black improves the shadow detail differentiation between those details and a black background (eventually at the expense of contrast between signal levels), but can't possibly achieve the same shadow detail as lowering the black level to zero.

Also note that if you actually set the black level control to 16 on the display (which means the display outputs its lowest possible lumens at level 16 but not at any higher digital value) then all dark levels starting at 17 will already be above black. So by your definition you don't lose any shadow detail on any calibrated display and you don't need any "black level gamma compensation".

Enough of this nonsense.

If levels were indistinct and some merged together (crushed) or were lost entirely (clipped) then I would say the shadow detail was "missing."
If it is still there and completely visible, only with a reduced contrast, the detail is still there.

What I am suggesting (using black level compensation) is not the same as indiscriminantly raising the brightness/gamma control on a display, you are still maintaining the ratio for the steps between levels as 2.4 gamma, it's just offset to compensate for the increased black level.

On a very low contrast display, you are going to see shadow details being crushed, but most HT projectors are fairly good these days.


Things aren't so black and white. A 3-chip 1080p projector won't resolve as well as a single-chip DLP projector, and a projector in general doesn't resolve as well as a flat panel. No-one goes around saying that you aren't seeing "full 1080p" when using projectors though.

Do you really mean to say that if you don't have a display capable of 70-80,000:1 contrast, you are losing shadow detail?
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post #128 of 162 Old 09-08-2011, 01:52 PM
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Quote:
Originally Posted by Chronoptimist View Post

if every step from 16-255 is visible, no shadow detail has been lost.

It is visible, but lower contrast. That is all.

Visible in what images? If 16 to 17 is visible when they are the only things in the image but disappear when a step 50 object is nearby where a higher CR projector would require the nearby object to be at step 55 or higher for the 16 to 17 step to disappear has any shadow detail been lost or gained? Just noticeable difference comes into play here.

This is the AV Science Forum. Please don't be gullible and please do remember the saying, "Fool me once, shame on you. Fool me twice, shame on me."
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post #129 of 162 Old 09-08-2011, 10:12 PM
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Quote:
Originally Posted by darinp2 View Post

Visible in what images? If 16 to 17 is visible when they are the only things in the image but disappear when a step 50 object is nearby where a higher CR projector would require the nearby object to be at step 55 or higher for the 16 to 17 step to disappear has any shadow detail been lost or gained? Just noticeable difference comes into play here.

Assuming you have sufficient separation (I'm not talking about really low contrast devices) it should be fine. In fact, because of how the eye works, shadow detail is likely to be more visible with black level compensated gamma as the difference between peak white and black is lower.

I really have no interest in arguing this point further though. You do not need a 70-80,000:1 contrast projector to avoid losing shadow details as long as you are using black level compensation when calibrating the display. If you adhere strictly to 2.4 power, you would be clipping lower values.


Going back to the "should I use 2.2 gamma, or the Rec 709 transfer curve with a 1.125 end to end" etc.
Here are a couple of screenshots from Baraka, the first "Tier 0" title I had to hand, which I hope will at least settle the 709/Power debate. With worse encodes, the image noise/macroblocking in dark areas is significantly worse.

BT.709, Power. Note: screenshots are taken using Video levels to make this more obvious on computer monitors, and please ignore the image dimensions, I just captured the window rather than fullscreen.

I still maintain that the only correct way to display films as intended, with a sufficiently high contrast display, is a pure 2.4 power curve.


For what it's worth, also I went back and updated my display calibration, and tried calibrating to 100nt again, as it's one of the monitor recommendations. (EBU specifies 80nt for 235, 100nt for 255, most others just say 100nt for "100% white") Boy, that sure looks bright in a dark room! I ended up with a headache within half an hour.

My recommendation for dark room viewing, even if you aren't using a projector, is 48nt at the display. (which is the recommended brightness for projectors)
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post #130 of 162 Old 09-08-2011, 10:30 PM
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Quote:
Originally Posted by HoustonHoyaFan View Post

Is it a free lunch or can increasing system gamma lead to loss of creative intent where the image looks too different (too much contrast) from what the DoP intended?

Absolutely. As DeMarsh found out in the 60's individuals prefer different gammas depending on the brightness of the surround. Hence for small monitors used in production, telecine, etc. where the room is seldom pitch black, he suggested a system gamma around 1.1 or 1.2. But for a front projector, with a completely black surround, something like 1.2 to 1.3 would be suggested. However, the absolute preferable values vary with individuals. I personally find gamma's above 2.6 for front projection to be too contrasty on most images.

The other thing to consider is that raising the gamma is also changing the color of the image. So an argument could be made that any gamma different from that used in the telecine transfer suite is distorting the color intend by the telecine colorist (which may or may not be the color intended by the DP and Director). So as you stray too far from the telecine colorists monitor's gamma you are introducing additional color variables into play. That's not to say the telecine colorist made optimum choices in the first place, but its a variable to consider.

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The world just seems much clearer when you are publishing projector reviews. Any chance we will see your take on the new crop (VW95, JVC X30/70/90, SIM2 Nero, ) in WSR in the near future?

Thanks. I don't know right now what my future plans are with regard to projector reviews. I sold AccuPel, but then took time off to design the new AccuPel DVG-5000 video generator, and then the 3D option for the DVG-5000, and now I'm working on documentation, etc. for a fantastic new DVG-5000 feature that will appear soon (the most exciting thing I've ever done in a video generator). After that, I'm not sure if I will un-retire to write some more projector reviews or not. I may just write some technical articles instead.

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post #131 of 162 Old 09-08-2011, 11:57 PM
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Quote:
Originally Posted by Chronoptimist View Post

What I am suggesting (using black level compensation) is not the same as indiscriminantly raising the brightness/gamma control on a display, you are still maintaining the ratio for the steps between levels as 2.4 gamma, it's just offset to compensate for the increased black level.

Ok lets try your method and see how well it works.

Let's set a 2% video level on a 5,000:1 projector to have the same contrast as 2.4 gamma 50,000:1 projector. The 50,000:1 projector has a black level equal to 0.002% of its maximum output. A 2% level on 2.4 gamma projector would be 0.0084% of its maximum output, and therefore have a contrast ratio above black of 4.2:1. Therefore to achieve that same contrast ratio on the 5,000:1 projector, the 2% level would have to be offset to 0.084% of its maximum output. i.e. it has to be 10x higher because the projector's contrast ratio is a factor of 10 lower.

OK? We only offset the gamma curve on the 5,000:1 projector by less than 0.1% of the projectors maximum output. That's such a small amount of offset we should have no problem implementing that offset 2.4 gamma curve, right? Well, let's see.

You say we can maintain the same ratio of steps as a 2.4 gamma projector. Really? On the 50,000:1 2.4 gamma projector the contrast ratio between a 40% video level and that 2% video level is 1326:1. [(40/2)^2.4]

So since the 2% level on the 5,000:1 projector is 0.084% of its maximum output, the 40% level would have to be 0.084% x 1326 = 111% of its MAXIMUM output level for a 2.4 gamma. How exactly are you planning to calibrate its gamma curve to produce 111% of its MAXIMUM output? Then at a 100% video level the 5,000:1 projector would have to output 1000% of its MAXIMUM output level. 10 times its MAXiMUM output level. Good luck with that. Your method is going to clip the 5,000:1 projector at its MAXIMUM output below a 40% video input level. I don't see that looking too good.

So as I already pointed out, black level gamma compensation works nothing like you think and has several tradeoffs and drawbacks that you aren't aware of because you don't know how it works.

But why are you even bothering with black level compensation when according to your definition of shadow detail no projector losses any shadow detail?
You said that there is no loss of shadow detail as long as each level above black is really above black (a bogus definition). So by your definition, all projectors regardless of their contrast ratios will have no loss of shadow detail as long as they are calibrated to have their black level at video level 16. By your definition no projector has any loss of shadow detail unless you calibrate it wrong, and therefore no black level compensation would ever be necessary (by your definition).

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Things aren't so black and white. A 3-chip 1080p projector won't resolve as well as a single-chip DLP projector, and a projector in general doesn't resolve as well as a flat panel. No-one goes around saying that you aren't seeing "full 1080p" when using projectors though.

Of course they do (and I do). We are extremely concerned about contrast sensitivity functions, else all projectors would just use the cheapest plastic lens they can buy, and who would ever bother focussing their projectors when they just look the same in focus or out of focus? Are you completely unaware of the debates between DLP and LCoS projectors based on modulation transfer and contrast sensitivity functions?

What next? All projectors produce the same colorimetry because they all have red, green, and blue primaries?

Quote:


Do you really mean to say that if you don't have a display capable of 70-80,000:1 contrast, you are losing shadow detail?

Have you ever looked at a properly calibrated CRT projector? If so, I don't know why you would ask that question. Yes, even the best fixed-pixel projectors produce imperfect shadow detail discrimination. But they are much better than 5,000:1 projectors.

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post #132 of 162 Old 09-09-2011, 12:56 AM
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It only makes sense if you have two projectors showing dark scenes, that the one with better contrast will have better shadow detail on some scenes when those scenes produce an intra-scene contrast above a certain spec when viewing a dark scene.


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post #133 of 162 Old 09-09-2011, 04:44 AM
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Quote:
Originally Posted by gregr View Post


The other thing to consider is that raising the gamma is also changing the color of the image. So an argument could be made that any gamma different from that used in the telecine transfer suite is distorting the color intend by the telecine colorist (which may or may not be the color intended by the DP and Director). So as you stray too far from the telecine colorists monitor's gamma you are introducing additional color variables into play. That's not to say the telecine colorist made optimum choices in the first place, but its a variable to consider.

When you say the color changes are you referring to saturation changes?

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post #134 of 162 Old 09-09-2011, 05:01 AM
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Quote:
Originally Posted by Geof View Post
When you say the color changes are you referring to saturation changes?
I don't think gamma can change the xy position of the colors so saturation would not change. Instead the Y, brightness, of the colors would change. The Y of a color is always a relative value based on the Y of white, but when your display uses a different gamma than the display on which material was mastered, those relative values will be different on the two displays. Changes in Y can really change how a color looks. There used to be a website that had color swatches that had the same xy values but a different Y.

Some purists will now argue that this is further evidence that in order to view a movie as it was intended then you should use the gamma that was used on the studio monitor. If they want to do that that is fine. I would suggest that if they really want to see things the way they were intended to be seen, that they should sell their projectors and go out and buy a 23 inch studio monitor to watch everything on. I doubt that anyone will take me up on this suggestion.

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post #135 of 162 Old 09-09-2011, 05:01 AM
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Quote:
Originally Posted by Geof
When you say the color changes are you referring to saturation changes?
Light biases your eyes and changes your perception of color. As Poynton points out on his WP gamma should be determined by display brightness and ambient conditions. In a mastering suite there is a low level of ambient light that biases your eyes and would affect your perception of color. The EE color box white papers discuss this and you'll be seeing a lot more about this with future calibration tools. Great to see Greg back by the way! Always love reading his insights into these things.

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post #136 of 162 Old 09-09-2011, 07:21 AM
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Quote:
Originally Posted by Geof View Post

When you say the color changes are you referring to saturation changes?

I can't speak for Greg, but imagine an object that is encoded as 50% video level green and 20% video level red. Changing the gamma can change the color of that object (make it more green or more red).

--Darin

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Quote:
Originally Posted by darinp2 View Post

I can't speak for Greg, but imagine an object that is encoded as 50% video level green and 20% video level red. Changing the gamma can change the color of that object (make it more green or more red).

--Darin

Is this so?

When I calibrate using a CMS that works well, my xy color positions do not change when I change gamma. Y does.

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post #138 of 162 Old 09-09-2011, 08:07 AM
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Here are some pics after gamma adjustments. I should have made them bigger, I will go back and fix them later.
Look at the color of the flower in the last pic. This is a plain GAMMA adjustment from Photoshop with no color adjustment at all.

Normal


Gamma 120%


Gamma 90% of Normal


Gamma 80% of Normal


Gamma 50% of Normal


Gamma 10% of Normal


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post #139 of 162 Old 09-09-2011, 08:40 AM
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Quote:
Originally Posted by gregr View Post

So as I already pointed out, black level gamma compensation works nothing like you think and has several tradeoffs and drawbacks that you aren't aware of because you don't know how it works.

Please try actually calibrating a display using the black level compensation feature found in a package such as calman professional.

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But why are you even bothering with black level compensation when according to your definition of shadow detail no projector losses any shadow detail?
You said that there is no loss of shadow detail as long as each level above black is really above black (a bogus definition). So by your definition, all projectors regardless of their contrast ratios will have no loss of shadow detail as long as they are calibrated to have their black level at video level 16. By your definition no projector has any loss of shadow detail unless you calibrate it wrong, and therefore no black level compensation would ever be necessary (by your definition).

Black level compensation is necessary to try and stick as close to the target curve as a given display can, without clipping shadow details, running a much lower gamma, or using an s-curve gamma.

Most lower contrast displays simply come calibrated (and may only have the option) to run at a much lower gamma. Panasonic's old plasmas used to be below 2.0 without any kind of gamma control for example. (never understood the praise they got as a result, the image looked completely washed out)

Black level compensation simply puts the display as close to the target as it can without clipping. If the display doesn't have enough contrast, the image may end up looking quite bad, but unless it has very poor gradation, shadow detail should all be visible.

I am not saying that increasing contrast doesn't improve the image quality significantly, just that it is not necessary to display all the shadow detail in an image.

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Originally Posted by gregr View Post

Of course they do (and I do). We are extremely concerned about contrast sensitivity functions, else all projectors would just use the cheapest plastic lens they can buy, and who would ever bother focussing their projectors when they just look the same in focus or out of focus? Are you completely unaware of the debates between DLP and LCoS projectors based on modulation transfer and contrast sensitivity functions?

I am not saying it isn't important, but no-one goes around saying that JVC's projectors can't display a 1080p image, for example.

They are still 1080p devices, they just aren't nearly as sharp as DLP.

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What next? All projectors produce the same colorimetry because they all have red, green, and blue primaries?

No, but if their gamut exceeds Rec709, that display should be capable of excellent colorimetry if they have good enough gradation. (you can end up throwing away a lot of levels to constrain gamut)

If there isn't enough gradation, you can end up with an image that measures Rec709, but looks terrible. It may still be a better result than letting it run at its native gamut, however.
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Have you ever looked at a properly calibrated CRT projector? If so, I don't know why you would ask that question. Yes, even the best fixed-pixel projectors produce imperfect shadow detail discrimination. But they are much better than 5,000:1 projectors.

I have not had the opportunity to, unfortunately. However, while I have only owned three projectors over the years, I have had most of the higher-end flat panels, and my primary display had remained a LUT calibrated Sony FW900 CRT, which has now in the last year finally been replaced with a HX900 local-dimming LED backlit LCD (also using a LUT for calibration) so I am very aware of how high contrast displays look when running 2.4 gamma.
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post #140 of 162 Old 09-09-2011, 08:43 AM
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Originally Posted by Chronoptimist View Post

Please try actually calibrating a display using the black level compensation feature found in a package such as calman professional.

You are making me laugh. Telling Greg Rogers to try calibrating a display is like telling Nolan Ryan to try throwing a fast ball.

Are you familiar with Greg's resume?

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post #141 of 162 Old 09-09-2011, 09:19 AM
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Originally Posted by Lawguy View Post

You are making me laugh. Telling Greg Rogers to try calibrating a display is like telling Nolan Ryan to try throwing a fast ball.

Are you familiar with Greg's resume?

He does not seem at all familiar with black level compensation considering his "run to the patent office" comments for a feature that's been in most calibration packages for years. I am not doubting his ability to calibrate a display otherwise.

I have no idea who this "Nolan Ryan" fellow is though.
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post #142 of 162 Old 09-09-2011, 09:20 AM
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Originally Posted by Chronoptimist View Post

I have no idea who this "Nolan Ryan" fellow is though.

Some guy I seen on the front of my hamburger meat packages.


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post #143 of 162 Old 09-09-2011, 09:25 AM
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Nolan Ryan.

Affable Nitwit
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post #144 of 162 Old 09-09-2011, 09:45 AM
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Back to the original topic of how much contrast makes a noticeable improvement, the topic originally was 15,000:1 vs. 40,000:1.

Of course it's an improvement, but I bet most people wouldn't even be able to tell in MOST movies unless you had the two side-by-side. You guys aren't most people and the higher in contrast you go after a point, the darker the scene needs to be to see a difference, so the fewer scenes you notice it in. Surely most in here can notice it, but is it worth paying the extra cash for MOST people, my feeling is not really. Sure if you have cash to burn, even a $500 martini might be worth it.

As I like to say, serve me up the Milky Way in Milky Gray


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post #145 of 162 Old 09-09-2011, 09:59 AM
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Quote:
Originally Posted by Chronoptimist View Post

He does not seem at all familiar with black level compensation considering his "run to the patent office" comments for a feature that's been in most calibration packages for years.

Rather than trade insults with Mr. Chronoptimist I'll simple ignore him from here on out. I think my example of his "black level compensation" method above speaks for itself, and I look forward to seeing a 5,000:1 projector calibrated with his method that has NO loss in shadow detail compared to a 50,000:1 projector. That truly would be a valuable patent.

So on that subject, and to Mr. Chronoptimist, nothing further needs to be said.

Greg Rogers
Video Engineer/Product Designer

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post #146 of 162 Old 09-09-2011, 10:05 AM
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Originally Posted by Chronoptimist View Post

I am not saying it isn't important, but no-one goes around saying that JVC's projectors can't display a 1080p image, for example.

Joe Kane has done exactly that in his demos of his Samsung projectors.

This is the AV Science Forum. Please don't be gullible and please do remember the saying, "Fool me once, shame on you. Fool me twice, shame on me."
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post #147 of 162 Old 09-09-2011, 10:05 AM
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Originally Posted by gregr View Post

Rather than trade insults with Mr. Chronoptimist I'll simple ignore him from here on out.
So on that subject, and to Mr. Chronoptimist, nothing further needs to be said.

It was an interesting back and forth anyhow.
Seems like every thread that goes heavy into the technical aspects of a subject ends up with someone ignoring someone else.

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Originally Posted by darinp2 View Post

Joe Kane has done exactly that in his demos of his Samsung projectors.

Any of us that have expressed too strong opinions at times (which I'm sure almost all of us are guilty of at least once), have usually paid for it in the receiving of massive flamage. Not that my opinion is to be taken that seriously as others...

You guys know where to send the hate mail to, or do you??...


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post #148 of 162 Old 09-09-2011, 10:29 AM
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Originally Posted by Lawguy View Post

Is this so?

When I calibrate using a CMS that works well, my xy color positions do not change when I change gamma. Y does.

Are you using any patterns where the different primaries have different levels in the same pattern, or only patterns with the same levels? If xy and Y all stay the same for 100% green and only Y changes for 75% red then imagine what happens to x and y for an object that is a mix of 100% green and 75% red.

This is the AV Science Forum. Please don't be gullible and please do remember the saying, "Fool me once, shame on you. Fool me twice, shame on me."
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post #149 of 162 Old 09-09-2011, 10:35 AM
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For those that missed it, I posted the gamma adjusted clown pics above which should be a representation of what would happen on a PJ as well, shows what happens to even a yellow color when the gamma was decreased too much, the yellow FLOWER turned fluorescent red when the gamma was dropped to 10% of the original image.


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post #150 of 162 Old 09-09-2011, 10:57 AM
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If the ability to show the difference between 16 and 17 is not called "shadow Detail" what then is a better term for this? That is how I would have described it, but others seem to disagree. I am interested in hearing from Kris / Darin / or Greg. My though process was if you could differentiate 16 from 17 you would not be losing shadow detail.

*With lower or anything that’s not infinite on/off contrast you would lose depth / realism / and tint the color with the "black" output of the projector, but still be able to see all the shadow detail (even if it is contaminated with the issues.)*

This is a real question and not one I am asking to start a fight with.

I'm going to throw this out for you Greg and please let me know if I am correct...

If I understand Gregr thoughts on shadow detail, anything that effects the true depth/color of true black and low IRE steps is losing shadow detail, is this a correct statement?
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