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Discussion Starter #1
Hi guys.


I am in the process of testing HD Progressive 0.9 (light grey) and HD Progressive 1.1 Contrast (more grey, but not dark grey) from Da-Lite.


One thing is that they are dimmer than the HD Progressive 1.1, but what annoys me it that white does not look white anymore. It looks more light grey. A bit like how white subtitles look like in the "Cinema Mode" with the lens aperture all closed down. :( This will - from what I know from using Photoshop Lightroom - affect other colors too.


So what is the "trick" to getting light screen like 0.9 HD Progressive to display white correctly?


So far I have set the Screen Adjust to fit the HD Progressive 0.9, but it is not enough https://de.jvc.com/microsite/de/dla-x90/screen_ajustment.html#x30 - so what is the next thing to try?








 

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If you're currently comparing the lower-gain grey screen sample next to your white screen, then you'll always notice how that lower-gain screen is dimmer and more grey/dingy looking, BUT unless the difference is really big you typically won't notice this nearly as much (often not at all) once all of your image is on that slightly lower-gain grey screen. That duller white appearance should stop being noticeable once you are using a full screen OR if you black out all of the image except the part that falls onto the grey sample.

Now, if the screen was only 60% as bright as your previous screen, or if it had a visible tint to its color (for example, if it tinted your image blue/cold), then it is likely to always look different even at full-size.

Side-by-side comparison is a very good thing, but it does have this one specific "shortcoming" (feels like the wrong word to use) that you just noticed...it can make differences in gain/brightness that often appear small on their own become much more noticeable while they're directly compared.
 

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Discussion Starter #3
If you're currently comparing the lower-gain grey screen sample next to your white screen, then you'll always notice how that lower-gain screen is dimmer and more grey/dingy looking, BUT unless the difference is really big you typically won't notice this nearly as much (often not at all) once all of your image is on that slightly lower-gain grey screen. That duller white appearance should stop being noticeable once you are using a full screen OR if you black out all of the image except the part that falls onto the grey sample.

Now, if the screen was only 60% as bright as your previous screen, or if it had a visible tint to its color (for example, if it tinted your image blue/cold), then it is likely to always look different even at full-size.

Side-by-side comparison is a very good thing, but it does have this one specific "shortcoming" (feels like the wrong word to use) that you just noticed...it can make differences in gain/brightness that often appear small on their own become much more noticeable while they're directly compared.

Thanks for your input.


I was using Planet Earth Ice episodes. And that snow and those icebears just did not look as I wanted it to. I geuss there is a also a bias from being used to the old 1.3 gain screen.


The 1.1 HD Progressive definitely looks more white.




 

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So why are you looking to change to Grey? What are you trying to fix with the non white screen? If room environment is the issue, maybe fix the room rather than replace the screen?
 

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Discussion Starter #5
So why are you looking to change to Grey? What are you trying to fix with the non white screen? If room environment is the issue, maybe fix the room rather than replace the screen?



The HD 0.9 is only very light grey. My 1.3 was bought for a CRT back in the day. I do not need 1.3 gain anymore.


MY room is good, sidewalls are 45% grey and front, back wall and ceiling is 65% grey. Dark furniture and black out curtains. But there are still some light leaks under doors and around the curtain. So I am looking for that little pinch of salt that will complete the experience.



 

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A neutral matte grey screen can make whites just as bright as a matte white screen. You just have to increase projector lumens to account for any loss of gain. For example, given the same projector lumens a 0.8 gain matte grey screen will produce 80% as bright whites as a 1.0 gain matte white screen. However, increasing projector lumens by the correct percentage on the matte grey screen will make whites equally as bright as on the matte white screen.
 

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@Dave in Green and @Ftoast did a good job of explaining what is happening. The problem is not in the screen it is in your eyes when comparing A/B of Gray/White at the same time.

Your eyes each have an iris and it opens and closes to adjust to the average brightness of the image to allow you to get the best perceived contrast of any given image. Doing an A/B is asking your eyes to adjust two things at once and because the sample is likely small compared to the brighter screen your eyes are favoring the larger brighter image. then to compound the problem you can’t adjust your projectors brightness to two samples at once so you have it set to what is your normal brighter higher gain screen.

Something to think about and if you have a light meter you can try. If you are sitting say in your kitchen with the lights on reading the paper you will feel it is a nice bright room. Now if you go outside to read on your deck and the sun is shining you will say it is also a nice bright setting and might guess it is even twice as bright. If you take your light meter and measure it you might find out it is 10 times as bright. That is because your eyes in a split second adjusted trying to keep it constant.

Eye adjustment is measured in f-stops just like old manual cameras had adjustments. Each f-stop doubles the light or halves the light depending on the direction you are going. The human eye can adjust 26 f-stops I’m told. So that would be numerical in terms of times brighter 1, 2, 4, 8, 16, 32, 64, 128, ….. 26 times if you want to keep going you will see the fantastic range the eye has. There are some drawbacks. At night we can see the stars as our iris is wide open. Those same stars are still up there during the day but we can’t see them as the iris is closed many f-stops because of the sun and to see those faint stars we would need the ability the wide iris give us but if it was that open the sun would be blinding bright. So we get a huge range but not all at once.

Front projection can work over a variety of iris f-stops. By design the best is when it is on the very dark end of the range with a very good projector making very good black levels and of course in a very good room. That’s how CRT projectors worked. Now there is a trend to go much brighter combating ambient light forcing our eyes iris open more and giving us perceived blacks.

It’s all about the eyes. I have a .5 gain neutral gray stealth screen wall and trust me my perceived whites look nothing like gray whites. I have double the lumens I would need for a white 1.0 screen and the result is the same in terms of whites. :)
 

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Just like to add these fine gentlemen answered the same question for me last year refarding low gain neutral matte grey and dark grey with gain(alr) and yes once you are looking at the full image the duller white is only noticeable in direct comparisons.

Also, if the screen has a blue push you can adjust it out easily in the projectors white balance controls
 

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Discussion Starter #10
@Dave in Green and @Ftoast did a good job of explaining what is happening. The problem is not in the screen it is in your eyes when comparing A/B of Gray/White at the same time.

Your eyes each have an iris and it opens and closes to adjust to the average brightness of the image to allow you to get the best perceived contrast of any given image. Doing an A/B is asking your eyes to adjust two things at once and because the sample is likely small compared to the brighter screen your eyes are favoring the larger brighter image. then to compound the problem you can’t adjust your projectors brightness to two samples at once so you have it set to what is your normal brighter higher gain screen.

Something to think about and if you have a light meter you can try. If you are sitting say in your kitchen with the lights on reading the paper you will feel it is a nice bright room. Now if you go outside to read on your deck and the sun is shining you will say it is also a nice bright setting and might guess it is even twice as bright. If you take your light meter and measure it you might find out it is 10 times as bright. That is because your eyes in a split second adjusted trying to keep it constant.

Eye adjustment is measured in f-stops just like old manual cameras had adjustments. Each f-stop doubles the light or halves the light depending on the direction you are going. The human eye can adjust 26 f-stops I’m told. So that would be numerical in terms of times brighter 1, 2, 4, 8, 16, 32, 64, 128, ….. 26 times if you want to keep going you will see the fantastic range the eye has. There are some drawbacks. At night we can see the stars as our iris is wide open. Those same stars are still up there during the day but we can’t see them as the iris is closed many f-stops because of the sun and to see those faint stars we would need the ability the wide iris give us but if it was that open the sun would be blinding bright. So we get a huge range but not all at once.

Front projection can work over a variety of iris f-stops. By design the best is when it is on the very dark end of the range with a very good projector making very good black levels and of course in a very good room. That’s how CRT projectors worked. Now there is a trend to go much brighter combating ambient light forcing our eyes iris open more and giving us perceived blacks.

It’s all about the eyes. I have a .5 gain neutral gray stealth screen wall and trust me my perceived whites look nothing like gray whites. I have double the lumens I would need for a white 1.0 screen and the result is the same in terms of whites. :)

Thanks for the clarification. Now - how about a positive gain grey screen? I am testing the HD Progressive 1.1 Contrast which is a darker grey than the light grey HD Progressive 0.9. - but still FAR from the dark grey of the HD Progressive 0.6



 

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Discussion Starter #11
btw - what do people think of grey screens for HDR material? Does it worsen or improve - or not affect the dynamic range??


:confused:
 

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btw - what do people think of grey screens for HDR material? Does it worsen or improve - or not affect the dynamic range??


:confused:
They don't.
For HDR the highest dynamic range is required (the deepest black/whitest white). Since projectors can't reach the nits value of HDR TV's, that usually means a bright projector/screen setup, that ideally can also display good blacks.
 

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Grey screens were used back in the day to try and increase the perceived black level of the digital projectors that were new to the market and did not cut the mustard compared to CRTs. For best possible image you want a white screen ,gain of 1, with no texture, no color shift, and artifacts in a dark room with no reflective surfaces and no other light source. Seems from your room description you are very close to having a good environment, other than the light under the door. Why mess with low gain non white screens when fixing the issue would eliminate the need for a grey screen?
Have you looked at this screen fabric report, it does not have every fabric but may be of some help
https://www.accucalav.com/wp-content/uploads/accucal_front_projection_screen_report.pdf
 

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Thanks for the clarification. Now - how about a positive gain grey screen? I am testing the HD Progressive 1.1 Contrast which is a darker grey than the light grey HD Progressive 0.9. - but still FAR from the dark grey of the HD Progressive 0.6



A matte screen with lambertian reflectance will have the same brightness when viewed from any angle of the viewing cone. By definition all matte (lambertian) grey screens must be
 

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btw - what do people think of grey screens for HDR material? Does it worsen or improve - or not affect the dynamic range??


:confused:
Think of it in simplest terms. A 0.5 gain matte grey screen reflects exactly half as much projector image light as a 1.0 gain matte white screen. Since the screen is a passive device it reflects all light equally, from darkest color to lightest. Going from a matte screen reflecting light equally across the viewing cone to one with directional gain simply redistributes the light within the viewing cone with equal reflectance for all colors from darkest to lightest. Confusion can creep in when we read some of the screen marketing claims that suggest performance attributes at odds with the science. :)
 

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I'm currently dealing with this same problem. I have samples of Seymour Glacier White and Gray and SilverTicket white and gray. When compared side by side I like the whites from the white and the blacks from the gray. I wonder if I should only compare one at a time, because side by side makes it very difficult to pick (see attached image). This is with a epson 5050ub on high with a 144" size from ~14ft (seating distance is ~10ft) so there should be plenty of fL to go around (~42fL based on projectorcentral). The room isn't light treated though so the walls are gray, but the room has a vaulted ceiling and plenty of space on the sides, but I still feel during bright scenes the room gets lit up from reflections. Is it possible to calibrate the projector so I can get the whites as bright on the gray screen as they are on the white or am I just being fooled by having them side by side and it isn't possible (but I probably wouldn't notice if they weren't side by side)?
 

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btw - what do people think of grey screens for HDR material? Does it worsen or improve - or not affect the dynamic range??:confused:

I'm currently wrestling over whether to move to a higher gain screen due to my feelings that HDR is too often too dark. I was initially trying to make adjustments via calibrating with HCFR software and a colorometer. In the end I found that the source video along with the director's decisions made more difference than any adjustments I was making.

Modifying screen gain seemed to only nibble around the edges in a war between contrast loss and higher brightness (whiter whites). As an example watch HDR content on Netflix, "I - Land" which is shot in daylight and the tropics, it's always dull and purposely shot in shadow. A great example that HDR brightness isn't your equipment's fault is seen in two HDR series which are both shot in dark grimy, sooty, blackish environments. View Prime Video's Carnival Row which is over dark then watch season one episodes of Peaky Blinders and see how an almost identical dark environment is properly lit showing off HDR.

Peaky Blinder (first season) has the whole array of scenes from night, low lit rooms, smokey rooms with high contrast bright streaming sunlight including that dusty look and crystal clear day scenes. Watch similar scenes in Carnival Row and you bounce between simply too dark invisible details versus my god the contrast is horrible. Some other 4K HDR videos that got the lighting right are Netflix - Travelers and Prime's - Expanse (season 2-3 as season 1 has significant blue shift). Most of the other Netflix HDR videos have gone to the dark side. With Netflix's Marco Polo, I almost cried as the supreme effort in costumes and grand settings are primarily shrouded in smoky haze or unnecessary darkness which dulls colors.

I recently searched on why so many videos are over dark (not even HDR related) and found I'm not the only one complaining. It seems that more often than not it's the director's/producers decision and no AV equipment changes or adjustments are going to make up for their poor judgement. It's a trend from avanguard films of yesteryear.

I think these "artists" need to actually watch their dark content in ordinary people's viewing rooms and see how often their content can't be enjoyed or effectively communicate as they want to be known as "artists" rather than provide viewable entertainment. I've read much the same about imbalanced audio where you can't make out the dialogue due to whispering or background sounds. The producers of these shows need to wake up as the capabilities of the 4K HDR/Dolby Vision, multi speaker digital audio reveal how poor their "artistic" decisions really are. It's sad when the blank canvas so badly out strips the artists capabilities.
 

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... Is it possible to calibrate the projector so I can get the whites as bright on the gray screen as they are on the white or am I just being fooled by having them side by side and it isn't possible (but I probably wouldn't notice if they weren't side by side)?
You obviously haven't read the previous posts in this thread that already answered the question you just asked. :)
 

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Hi guys.


I am in the process of testing HD Progressive 0.9 (light grey) and HD Progressive 1.1 Contrast (more grey, but not dark grey) from Da-Lite.


One thing is that they are dimmer than the HD Progressive 1.1, but what annoys me it that white does not look white anymore. It looks more light grey. A bit like how white subtitles look like in the "Cinema Mode" with the lens aperture all closed down. :( This will - from what I know from using Photoshop Lightroom - affect other colors too.


So what is the "trick" to getting light screen like 0.9 HD Progressive to display white correctly?


So far I have set the Screen Adjust to fit the HD Progressive 0.9, but it is not enough https://de.jvc.com/microsite/de/dla-x90/screen_ajustment.html#x30 - so what is the next thing to try?








Your projector will need to be properly calibrated to the screen.

I've owned the HD Pro 1.1, 0.9, and now own the Stewart ST100. All of them can be calibrated to 6500K.

If you with the 0.9, you need to have a pretty good room.
 

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Discussion Starter #20
Your projector will need to be properly calibrated to the screen.

I've owned the HD Pro 1.1, 0.9, and now own the Stewart ST100. All of them can be calibrated to 6500K.

If you with the 0.9, you need to have a pretty good room.



Is there a guide "out there" to calibrating JVCs with HD Progressive?



 
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