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post #181 of 195 Old 05-20-2020, 12:19 PM
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Originally Posted by Mike Garrett View Post
I think what urm was saying regarding seeing yellow, that should not be there. If it is, then it is a problem with the calibration and if correctly calibrated, you would not be seeing that.
Who's "URM"? You've gotta stop watching re-runs of Alita, Battle Angel.

Agreed on yellow... to get an objective RGB/ x. y. coordinates standard first.
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post #182 of 195 Old 05-20-2020, 12:20 PM
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Originally Posted by Mike Garrett View Post
I think what urm was saying regarding seeing yellow, that should not be there. If it is, then it is a problem with the calibration and if correctly calibrated, you would not be seeing that.
D65 is a slightly yellow hued white. Doesn't matter what it is on.
So I agree it shouldn't be yellow but I didn't say it was 'yellow', but that it is more yellow than actual white is.
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post #183 of 195 Old 05-20-2020, 12:28 PM
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Originally Posted by Archibald1 View Post
D65 is a slightly yellow hued white. Doesn't matter what it is on.
So I agree it shouldn't be yellow but I didn't say it was 'yellow', but that it is more yellow than actual white is.
Shouldn't D65 look bluer? Since the black body radiator we're most familiar with is the sun, which is about 5,900K.

Tungsten has 3,200K which looks yellower when outside in the noon sun and looking into a room.

Quote:
Professional TV monitors use a standardized set of SMPTE color phos- phors that create “white” at 6,500K. This is bluer than sunlight, and much bluer than incandescent light. The color temperature of most home TV sets is considerably higher than 6,500K – commonly 7,100K in the United States and 9,300K in Japan.
http://www.mmresourcecenter.org/pdf/colortemp.pdf
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post #184 of 195 Old 05-20-2020, 12:48 PM
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Originally Posted by Debonaire View Post
Shouldn't D65 look bluer? Since the black body radiator we're most familiar with is the sun, which is about 5,900K.
Well the sun is a yellow colour but the light coming from it is not 'yellow'.

D65 is not sunlight either, it is a value for video white settled on by who knows who and when.
It is readily accepted that D65 is on the warmer side of white balance on devices and it is pretty obvious it is not the same as real things in real daylight. Also no two devices will have the same D65 either.
no doubt someone will now go off and find some data regarding sunlight etc etc to try to 'prove me wrong' but all I have ever been talking about is my perception being the only one I am interested in. So it would be folly.
I haven't said anything is wrong with D65 per sae, or I am right, I merely said I will tweak even a calibrated device until things look more real to me.
I love the way people only read half the posts and then try to rubbish others personal opinions and preferences.
I don't think I have even questioned the actual science behind it, I just said that it didn't necessarily fit with mine or many others perception. Ultimately, our personal perception is all we can use to judge things by.
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post #185 of 195 Old 05-20-2020, 01:44 PM
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Originally Posted by Debonaire View Post
Do you ever watch any Full Moon Features? A lot of their releases look real bad and the only way to make them at least watchable is to turn down contrast and brightness. Even on my Dwin HD700 CRT they looked like a movie on a first generation Sceptre LCD!

On my Oppo 103-D I have two memories for too bright and too dark.

Other examples prone to this are many old anime on dvd.

The only real problem in these cases, is when faces have their forehead look like someone stuck a mini sun there. No matter what you try to do, nothing gets rid of that!

I do not watch those movies. Those are direct to video. Anytime you venture from Sony, Warner and Disney post production the quality generally takes a hit.

What you are describing is the most common error I see in sources. Elevated blacks from a black level translation error.

I have a memory for that type of thing. You are also likely seeing an error in color with it from SMPTE-C color space being played back on a Rec 709 product. Those sources are older and were probably produced in SMPTE-C. It is possible to have a SMPTE-C color space on some displays. SMPTE-C was less saturated. Playing that in Rec 709 will make flesh tones over saturated.


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post #186 of 195 Old 05-20-2020, 01:46 PM
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D65 is close to clouds at noon on an overcast day.


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post #187 of 195 Old 05-20-2020, 09:20 PM
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Originally Posted by umr View Post
D65 is close to clouds at noon on an overcast day.
Yep.

"D65 corresponds roughly to the average midday light in Western Europe / Northern Europe (comprising both direct sunlight and the light diffused by a clear sky), hence it is also called a daylight illuminant."
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post #188 of 195 Old 05-21-2020, 02:04 AM
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Originally Posted by umr View Post
D65 is close to clouds at noon on an overcast day.


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Originally Posted by SirMaster View Post
Yep.

"D65 corresponds roughly to the average midday light in Western Europe / Northern Europe (comprising both direct sunlight and the light diffused by a clear sky), hence it is also called a daylight illuminant."
Isn't D65 being used the result of visually brighter but bluer CRT displays being more popular than CRTs using a more neutral white. With the standard in effect created to match the displays being used. That is the daylight illuminate created so as to be able to film/create nice looking images for the displays that would use the max white and so brightness and contrast of the displays. Daylight illuminates not simply being a x,y coordinate created by mixing R,G,B primaries but a light source outputting a whole spectrum of light with a waveform that mimics daylight.

Lots of white points could be said to be roughly equivalent to daylight from D48 afternoon to over D80 in the shade on a sunny day. And human vision adapts to them all to maintain color consistency in objects that is people do not look weirdly blue or red and a piece of paper looks white. And some TVs used to have user selectable white points so viewers could choose brighter bluer or warmer redder according to their personal preference.

But it is important the source material mastered white matches the white the display is using. If it is an exact match all the nuisances in the colors can be seen, they are not being tinted by a off-white white and contrast at least color contrast is not being undermined by the image being tinted. While if the white of the display and source material are too different from each other some objects colors may start to look unnatural, the eyes/brains ability to maintain object color consistency in different lighting environments may start to fail.
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post #189 of 195 Old 05-21-2020, 04:41 AM
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Originally Posted by dovercat View Post
Isn't D65 being used the result of visually brighter but bluer CRT displays being more popular than CRTs using a more neutral white. With the standard in effect created to match the displays being used. That is the daylight illuminate created so as to be able to film/create nice looking images for the displays that would use the max white and so brightness and contrast of the displays. Daylight illuminates not simply being a x,y coordinate created by mixing R,G,B primaries but a light source outputting a whole spectrum of light with a waveform that mimics daylight...
D65 is an xy coordinate. It can be created by a wide variety of light intensities at various wavelengths. This can be from monochromatic RGB lasers to a mixture of broad spectrum light.

I am not sure about the exact origin of the choice. It seems like a reasonable one to me. I have met many SMPTE engineers and some committee chairs. They do not strike me as fools. The bluer and greener the whitepoint the higher the light output you can get out of a projector.

D65 is not the only color used for whitepoint in the SMPTE standards. The DCI standard for white for cinema is bluer and greener than D65.

One of the challenges of measuring light is that all of the color meters are specified only to Luminant A. That light source has nothing to do with the light coming off a display. A meter can be excellent at Luminant A and poor at measuring a display. To match the CIE method for every color a meter must measure light with a specific number of segments over a specific range with a narrow bandpass. Anything else and you are only approximating the method which creates errors of varying degree.


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post #190 of 195 Old 05-21-2020, 09:46 AM
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Originally Posted by umr View Post
D65 is an xy coordinate. It can be created by a wide variety of light intensities at various wavelengths. This can be from monochromatic RGB lasers to a mixture of broad spectrum light.
D65 on the output side, the display side, is a xy coordinate.
On the input side its an illuminate whose waveform mimics daylight.

The system works because the viewers eyes/brain maintain the color consistency of objects by adjusting for the assumed illuminate. A object at midday is actually a different color to the same object in the evening because there is more blue light at midday and more red light in the evening, same goes for different weather conditions, shadow, going indoors. But the eyes/brain adjust all the objects colors for the changing lighting to maintain color consistency so you can recognize objects. The eyes/brain does this somehow by using reference objects and other processing.

The choice to use D65 was due to the availability of crt phosphors and desire for brightness. Same as the limited gamut was a choice dictated by display phosphors.
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post #191 of 195 Old 05-22-2020, 04:57 PM
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Originally Posted by umr View Post
I find UHP projectors to have the best image quality in home projectors. They have a significant advantage from the smaller light source size compared to other options like LED.


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Jeff, I see your statement about lamp preference. Are you including laser and HLD LED?

As you likely know, I have had a few projectors, including the Sony 695ES, the JVC NX7/RS2000 and laser and LED projection DLPs and demo'd a laser Lcos. I have to say that I find laser and both HLD and non-HLD LEDs to be superior than lamps in their 1) ability to display wider color, 2) light uniformity, 3) chromaticity stability, 4) minimal mosquito noise, 5) image calmness, and 6) of course long life. The list goes on...as far as laser projectors, they are incredibly bright too. And the blinding speed of their dimming ability alleviates pumping --and alleviates fear of mechanical iris failure for those who use a mechanical DI.

Don't get me wrong; I love my three chip Runco LS-10, but if it were matched against itself but with a laser, I would think the laser version would be better!!!

What am I missing in your conclusion on your preference for lamp projectors?


Edited: I have not demo'd the Sim2 Lumis 3D, SuperLumis or the JVC RS4500.
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post #192 of 195 Old 05-23-2020, 05:48 AM
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Question about Contrast ratio

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Originally Posted by Aztar35 View Post
Jeff, I see your statement about lamp preference. Are you including laser and HLD LED?
I am.

The best UHP products have advantages from the smaller size if the arc versus the larger LED light sources. The contrast of a projector is impacted by a the ratio of the light source to imager.

Consumer lasers have also not lived up to their durability expectations. I would be concerned about the cost of replacing the light source versus the $50 it costs me to swap out my lamp every 2000 hours or so.

Specific laser or LED based products can be better than specific UHP implementations.

My favorite projector is the SIM2 Lumis 3D-S. It is current the peak of what is possible with UHP to me.

The JVC RS4500 laser is my favorite of the consumer laser products, but I still prefer the Lumis to it’s image.

You can like whatever you like.

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post #193 of 195 Old 05-23-2020, 06:25 AM
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Originally Posted by umr View Post
I am.

The best UHP products have advantages from the smaller size if the arc versus the larger LED light sources. The contrast of a projector is impacted by a the ratio of the light source to imager.

Consumer lasers have also not lived up to their durability expectations. I would be concerned about the cost of replacing the light source versus the $50 it costs me to swap out my lamp every 2000 hours or so.

Specific laser or LED based products can be better than specific UHP implementations.

My favorite projector is the SIM2 Lumis 3D-S. It is current the peak of what is possible with UHP to me.

The JVC RS4500 laser is my favorite of the consumer laser products, but I still prefer the Lumis to it’s image.


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I should have stated in my post that I did not have a chance to see in person the Lumis or Super Lumis or the RS4500.
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post #194 of 195 Old 05-23-2020, 06:47 AM
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Question about Contrast ratio

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Originally Posted by Aztar35 View Post
I should have stated in my post that I did not have a chance to see in person the Lumis or Super Lumis or the RS4500.

A problem with judging a projector on what you see is the quality of the room and setup strongly impact the image performance.

I see very few implementations that put any product in it’s best light.

Here are a few war stories that put this in perspective...

Sony Motion Pictures was trying to figure out why Deluxe could not get their projectors color correct. They were very frustrated because they were doing post at both facilities. I gave them some suggestions to help. It is tragic that a large post production firm cannot get reasonable color on their post production projectors.

I have done multiple projector setups for the person who worked with the film prints for Steven Spielberg and IMAX along with others. One time after I finished he said it is crazy that I have to come from Missouri to do his setup on digital because he could not find anyone else who came close. I have had this comment from many in the motion picture business.

Getting great image performance is about many factors and the projector is only a piece of the puzzle. Obsessing over the projector alone is a mistake. A lower quality machine optimized can wipe the floor with a much better machine that is not.

I would focus on all things that impact the image. This means allocating effort and funds in ways that yield the best results for your budget.

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post #195 of 195 Old 05-23-2020, 06:55 AM
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Quote:
Originally Posted by umr View Post
A problem with judging a projector on what you see is the quality of the room and setup strongly impact the image performance.

I see very few implementations that put any product in it’s best light.

Here are a few war stories that put this in perspective...

Sony Motion Pictures was trying to figure out why Deluxe could not get their projectors color correct. They were very frustrated because they were doing post at both facilities. I gave them some suggestions to help. It is tragic that a large post production firm cannot get reasonable color on their post production projectors.

I have done multiple projector setups for the person who worked with the film prints for Steven Spielberg and IMAX along with others. One time after I finished he said it is crazy that I have to come from Missouri to do his setup on digital because he could not find anyone else who came close. I have had this comment from many in the motion picture business.

Getting great image performance is about many factors and the projector is only a piece of the puzzle. Obsessing over the projector alone is a mistake. A lower quality machine optimized can wipe the floor with a much better machine that is not.

I would focus on all things that impact the image. This means allocating effort and funds in ways that yield the best results for your budget.

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I appreciate the advice.
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