High Dynamic Range - HDR, is not about nits its about dynamic range !

alebonau

Well-known Member
I often see folks chasing more and more lumens for HDR... when infact as the video below describes ... its not about lumens.. its actually about dynamic range particularly since the uplift in luminance only adds little to dynamic range for HDR... what makes the dynamic range is infact black floor and contrast !

this video as I recall it was on unveiling of the jvc nx9 with value electronics. Kris who is also a calibrator and technical writer of sound and vision magazine and calls it well I think saying how with calibration to 22-23FL, as he has done in this case, can be a good show case of what can be achieved with HDR on projectors. With TVs.... I think its case of bright and then with more nits it still just looks bright ... so not too sure about this seeking of light like moths to a flame :D

ps with projectors i do think 30FL from personal experience works well, but good calibrators like kris can achieve pretty well with lower... 22-23FL as has done in this case

"Kris Deering of Deep Dive AV, explains the basics of HDR, that "it's not a brightness format. It's a dynamic format." That the deep black levels that JVC projectors bring to the picture create the proper image dynamics for the viewers. This event was held at Value Electronics in 2019 featuring the new 8K-eshift JVC NX9."

 
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Stridsvognen

Well-known Member
I posted that video long time ago, and it was deleted by the moderators, so interesting to see if they will let it stay up this time.

Anyway i totally agree with Kris on that one, but its not a popular standpoint on projector HDR on this forum.
 
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kenshingintoki

Distinguished Member
I agree, for HDR contrast is king. This isn't just for projection, its for TVs too. An OLED TV destroys LCD displays for HDR for this reason. That black floor allows specular highlights to really dance around the screen.

However I think the combination of contrast AND brightness is where thinks get very interesting!
 

howieeb

Active Member
This vid has been discused a few times and it's one of the reasons i'm hoping to average around 25ftl with our new setup. A fresh bulb at 30ftl to allow for dimming should do the trick.
 

Comer

Active Member
Very interesting. Seems like I have vindication for my decision, a few weeks ago, to close the iris on my x7900 to give 85nits peak brightness. I decided to do this as my living room, while has dark walls, is not treated and I don't want the extra brightness/reflections affecting contrast. It also gives a bit of head room as my lamp dims. HDR now looks great with MadVR.
 

alebonau

Well-known Member
This vid has been discused a few times and it's one of the reasons i'm hoping to average around 25ftl with our new setup. A fresh bulb at 30ftl to allow for dimming should do the trick.
hi howleeb, that sounds like a good approach...22-25 folk seem to achieve good result and 30FL woudl give some up the sleeve to allow for some drop off as lamp ages :)

Very interesting. Seems like I have vindication for my decision, a few weeks ago, to close the iris on my x7900 to give 85nits peak brightness. I decided to do this as my living room, while has dark walls, is not treated and I don't want the extra brightness/reflections affecting contrast. It also gives a bit of head room as my lamp dims. HDR now looks great with MadVR.

hi comer, thats a good thought less light less reflections... even in a dedicated room a friend of mine had his x7000 with 130" scope screen and is running low lamp with a pro calibration by one of best guys in the business here, so certainly possible on X series with lower light settings :)
 

alebonau

Well-known Member
ps some might remember this post by kris also explaining dynamic range... from perspective of high nit vs lower nit displays. this was originally posted on blu-ray.com that is a bit defunct at moment or id link to it :D

while talking about Tellies here it explains well the greater role that contrast plays than nits for determining dynamic range...

"Well lets introduce some simple math into the equation to show whether or not this is the case. HDR stands for HIGH DYNAMIC RANGE. Dynamic Range relates to the difference between the highest and lowest point a display can display. This can be expressed as a ratio by taking the highest point and dividing it by the lowest point. This is also known as on/off contrast ratio. So:
OLED: 1,080,000:1 (540/.0005)
LCD: 20,000:1 (1000/.05)

As you can see, OLED has SUBSTANTIALLY more dynamic range than the specs for LCD based display with 1,000 nits. The overall CR of a LCD is actually pretty sad and would result in blacks that look more gray than black. With low APL imagery the difference between the two would look massive. But most LCD displays have zoned backlighting that helps with this. When we move to Dolby Vision content it actually has frame by frame metadata for controlling zoned backlighting and dynamic contrast systems that should help even more."

so oled with about half the peak nit capable of LCD still trounces LCD for dynamic range due to OLEDs greater contrast capability.

higher nits is not always the answer ....especially if can end up with a pretty decent calibration even if using a larger screen....
 

Comer

Active Member
"90% of what you see in HDR is in the SDR range" amazing the extra money and effort we spend for just that 10%😁
 

alebonau

Well-known Member
"90% of what you see in HDR is in the SDR range" amazing the extra money and effort we spend for just that 10%😁
isnt it always the way :D definitely the extra money and effort ! money for the tech... and effort in the calibration... I actually think the tech is in some ways easy ... it just brings the capability but its in the calibration I think its make or break and bring the best from it :)

all well worth it though :D
 

lgans316

Distinguished Member
Higher nits may not be the answer but if you see a bright flashing storm that's in the region of 1500 nits, the display equipment must have the ability to not only tone map but also bring out as much highlight information as possible. The display could show a super bright image but without details and depth. Personally I think our human eyes are able to appreciate bright objects projected against a dark background over bright objects on a bright backdrop. This is where OLEDs usually shine especially in dark rooms and in the night scenes.
 

alebonau

Well-known Member
Higher nits may not be the answer but if you see a bright flashing storm that's in the region of 1500 nits,
I somehow doubt lightening is 1500 nits :) luminance in nature is stupendous... :D the article below is a good one....


"Nature has a lot of nits. The noonday sun measures around 1,600,000,000 nits and the night sky around 0.001 nits. Or, more relevant to us here, the average modern TV maxes out around 500-1,000 nits, and a movie theater screen maybe 50. We're starting to see some TVs pushing 1,500 nits, but that's still pretty rare and, in the case of the Samsung Q7, it gets dimmer after a few seconds."

the display equipment must have the ability to not only tone map but also bring out as much highlight information as possible. The display could show a super bright image but without details and depth.

absolutely we have to tone map to capture to capability of cameras...thats what happens with lightening

and

then tone map to display(the various display capabilities we have LCD/OLED/Projectors) .... its been going on forever and a day.... keeping in mind even mastering occurs well beyond 1000 nits and often at 4000 nits...10000 nits and we have no displays to handle anything of that nature... so we tone map...

however HDR is still as per opening post...very much down to dynamic range ... which is contrast :)
 

Luminated67

Distinguished Member
If they set a realistic peak limit then at least projector companies could design to accommodate it. If you think about it DTM is a less than ideal work around, adjusting individual scenes to allow the projector to show the scene in a range the projector can work with but ultimately not the way it was originally filmed.

Can’t recall the exact peak level for SDR I think it’s the very low hundreds but if HDR was no higher than 4-5 times this would still be a significant difference.

The real problem is the technology isn’t being driven my the movie industry it’s being driven by the TV industry.
 

tonyoramos1

Standard Member
Joe Kane has said that viewing studies have been conducted that show that viewers do indeed prefer content mastered for 200-300nits. Lots of professionals are calling for a future standard to use our extra brightness to elevate our average brightness from the 100nits we kept from SDR days
 

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