Dynamic tone mapping and projectors

Lee

Moderator
Thread tidied.

Please keep on the topic of dynamic tone mapping and projectors.
 

Stridsvognen

Well-known Member
Im the one who prefer all my HT content displayed below 14fl around 45 nit max, as that fits nicely with my eyes static dynamic range, being capable to enjoy a mix of dark and bright scenes without having to pause the movie while waiting my eyes to adapt to the next scene, so the content of the movie is never disturbed by my eyes limited static dynamic range. If going with a DLP or LCD, or a SONY projector for that matter brighter can help to open up your eyes iris to a point that when it goes dark, your eyes are clipping out the very elevated black level, and sudently its perceived as black, and just hope you not watching Harry Potter or some other dark movie. Thats where HDR on projectors can be perceived as better as you will likely have some highlight portions of the image forcing your iris open more often.

Just a fun thought.
When measuring contrast we measure the 0-100% ire difference, if you concider HDR being SDR + highlights, where is your start point of the highlights? 70% ire?, so now you open up your projectors iris to get whatever lightoutput you desire for HDR, and then you measure contrast from 0 to 70% ire, then it will be compatable to your SDR mastering. Dont bother that they often master the HDR content to sell the movie 1 more time, so forcing a different look to it.
What level do your DTM solution reserve for highlights?
 

bytehoven

Active Member
Just a fun thought.
When measuring contrast we measure the 0-100% ire difference, if you concider HDR being SDR + highlights, where is your start point of the highlights? 70% ire?, so now you open up your projectors iris to get whatever lightoutput you desire for HDR, and then you measure contrast from 0 to 70% ire, then it will be compatable to your SDR mastering. Dont bother that they often master the HDR content to sell the movie 1 more time, so forcing a different look to it.
What level do your DTM solution reserve for highlights?
Great question... this is where DTM starts to journey into the territory of making colorist choices. If there were a Dolby Vision layer designed to dynamically map HDR to the projector, might that be a better way to go to better preserve creative intent?

I think it is both the Dolby Vision profile 5 and profile 7 layers that can be pulled from some discs and streaming sources, and with a good 1000nit reference pq curve on the projector, you are getting closer to the colorist intent.

I don't think any projector yet supports being able to directly pulling either of those DV trim passes from content, but spoofing the EDID with some source devices, has been a way to see the potential of direct DV support.

Who better than the projector manufacturer to fine tune the use of a DV profile layer to achieve better HDR dynamic tone mapping performance within the dynamic range limitations of the projector?
 

Stridsvognen

Well-known Member
Great question... this is where DTM starts to journey into the territory of making colorist choices. If there were a Dolby Vision layer designed to dynamically map HDR to the projector, might that be a better way to go to better preserve creative intent?

I think it is both the Dolby Vision profile 5 and profile 7 layers that can be pulled from some discs and streaming sources, and with a good 1000nit reference pq curve on the projector, you are getting closer to the colorist intent.

I don't think any projector yet supports being able to directly pulling either of those DV trim passes from content, but spoofing the EDID with some source devices, has been a way to see the potential of direct DV support.

Who better than the projector manufacturer to fine tune the use of a DV profile layer to achieve better HDR dynamic tone mapping performance within the dynamic range limitations of the projector?
Manufactures can not support DV without a DV license, and last i looked DV would not license projectors.
When discussing projectors its a bit more complex, you have the guy with a 4m wide sound transparent screen getting 8fl on screen with a JVC NX9 and around 25000:1 contrast, or there is the other guy with the same projector who calibrated it to 20fl on a 2,4m wide screen with 60000:1 contrast, how can you build a tonemapping for these kinds of variations, and how will you as a creator make sure your creative intent is what these guys are watching?
 
Last edited:

Stridsvognen

Well-known Member
As a projection owner, you should probably hope that ALL titles were like the BR2049 disc. It is a title you have far more chance of getting a good WCG, 4K, Atmos presentation out of.
Exactely, however you still need a DTM to remap it to the projector, and as illustrated in the youtube clip you do that to make it just like the 1080P SDR edition.
However quite a few have bought a Lumagen or a Mad VR solution, a expensive panasonic or JVC projector just to do that, whos the smart ones, those selling you solutions to make your HDR look almost as good as your SDR disc, or those who just run the 1080P SDR disc that is perfectly mastered to your projectors capabilities?:rolleyes:
 

mb3195

Distinguished Member
Exactely, however you still need a DTM to remap it to the projector, and as illustrated in the youtube clip you do that to make it just like the 1080P SDR edition.
However quite a few have bought a Lumagen or a Mad VR solution, a expensive panasonic or JVC projector just to do that, whos the smart ones, those selling you solutions to make your HDR look almost as good as your SDR disc, or those who just run the 1080P SDR disc that is perfectly mastered to your projectors capabilities?:rolleyes:
1080p vs 4k though - this also makes a significant difference
 

kenshingintoki

Distinguished Member
I took a similar photo only I stood well back beyond my seating to get the projector in the shoot.

View attachment 1382385

And now that the screen is cinemascope all you see is the image on the screen without the borders, it truly does float in front of you.


I wish I could try and alr screen in your room with ur projector. I wonder if it would ink those blacks just that bit more.
 

jfinnie

Distinguished Member
Exactely, however you still need a DTM to remap it to the projector, and as illustrated in the youtube clip you do that to make it just like the 1080P SDR edition.
However quite a few have bought a Lumagen or a Mad VR solution, a expensive panasonic or JVC projector just to do that, whos the smart ones, those selling you solutions to make your HDR look almost as good as your SDR disc, or those who just run the 1080P SDR disc that is perfectly mastered to your projectors capabilities?:rolleyes:
Bye bye WCG, Atmos, 4k... It's the trade off no one with a top flight cutting edge projection and sound system wanted to have to be making...
 

Stridsvognen

Well-known Member
1080p vs 4k though - this also makes a significant difference
Ill say 4K screen resolution gives a difference on the big screen, but the difference between a upscaled 1080P to 4k or native 4k is not something ill notice at all, as long as the scaling is done properly. Remember a lot of people that is all exited about HDR is displaying it on a 1080P projector with a vibrator build in to shake the image, and mostly tracks P3 like pasta twisting around on a plate, in some cases even projectors with limited contrast unless they turn off the lamp when measuring the low level.
 
Last edited:

mb3195

Distinguished Member
Ill say 4K screen resolution gives a difference on the big screen, but the difference between a upscaled 1080P to 4k or native 4k is not something ill notice at all, as long as the scaling is done properly. Remember a lot of people that is all exited about HDR is displaying it on a 1080P projector with a vibrator build in to shake the image, and mostly tracks P3 like pasta twisting around on a plate.
the really depends on the 4k remaster.

Take alien, predator or die hard for example. The new 4k releases are a huge upgrade.
 

Stridsvognen

Well-known Member
the really depends on the 4k remaster.

Take alien, predator or die hard for example. The new 4k releases are a huge upgrade.
They are old movies, it has nothing to do with the capabilities of 1080P or 4K, its just the mastering process creating a new look, that could just as well have been done to the BD. None of those movies is shot with HDR or WCG in mind, so what they do to them is basically just twisting them and reselling, as the movies is already there, why not sell them to the consumers yet another time since they only have them on Laserdisc VHS DVD BD and now UHD, thats smart marketing, not creators intent.
 

mb3195

Distinguished Member
They are old movies, it has nothing to do with the capabilities of 1080P or 4K, its just the mastering process creating a new look, that could just as well have been done to the BD. None of those movies is shot with HDR or WCG in mind, so what they do to them is basically just twisting them and reselling, as the movies is already there, why not sell them to the consumers yet another time since they only have them on Laserdisc VHS DVD BD and now UHD, thats smart marketing, not creators intent.
That’s not really true though is it? If you play the above films to output 1080p and then let your PJ to the upscaling they don’t look as good as outputting them at full 4k.

there are plenty of other 4k releases that look much better than their 1080p counterparts, including new ones - in fact, most new releases, the 4k looks clearly better than the 1080p, to the point I don’t buy any blu rays anymore, only 4k discs. This is either because my Pj setup can deal with HDR properly, or 4k images looks better than 1080p or a combination of both the HDR and the 4k image.

Screen size has a big effect on how noticeable these are of course - on my 65” TVs I’m not fussed between 4k or 1080p
 

Stridsvognen

Well-known Member
That’s not really true though is it? If you play the above films to output 1080p and then let your PJ to the upscaling they don’t look as good as outputting them at full 4k.

there are plenty of other 4k releases that look much better than their 1080p counterparts, including new ones - in fact, most new releases, the 4k looks clearly better than the 1080p, to the point I don’t buy any blu rays anymore, only 4k discs. This is either because my Pj setup can deal with HDR properly, or 4k images looks better than 1080p or a combination of both the HDR and the 4k image.

Screen size has a big effect on how noticeable these are of course - on my 65” TVs I’m not fussed between 4k or 1080p
SONY and JVC projectors make a horrible job at upscaling, so to that point i understand, but if you let your Lumagen do the upscaling its a hole different matter.
Sony do react different to the upscaled image than JVC, no idea why, OPPO 203 upscaling to SONY looks bad, JVC perfect, i imagine its related to SONY image manipulation you cant turn off distorting differently depending the source signal. Part of the reason i dont like SONY is they simply cant let the user turn off all the enhancement.
Looking at the JVC N7 with 1080P upscaled to 4K 4:4:4 out of the OPPO 203 makes a image i have no complaints about, putting on the UHD edition i have plenty of scenes where im left looking for the remote to tweak a setting.
 

Luminated67

Distinguished Member
I wish I could try and alr screen in your room with ur projector. I wonder if it would ink those blacks just that bit more.
That was my old white 16:9 screen, the grey 2.35:1 is on another level with regards to blacks.

12BB7B74-B85F-4A0B-8DFF-2AA4AEADB21A.jpeg
 

kenshingintoki

Distinguished Member
That was my old white 16:9 screen, the grey 2.35:1 is on another level with regards to blacks.

View attachment 1382772

Yup. I just wonder what ALR would do versus Grey. Interesting to think right.

The general concensus is that you use a white screen in a room like yours (which is pretty much perfect room) but as you've seen,I think you've got remarkable results from grey screen and wonder if ALR would give any added benefits further (for perceived contrast).
 

Luminated67

Distinguished Member
Yup. I just wonder what ALR would do versus Grey. Interesting to think right.

The general concensus is that you use a white screen in a room like yours (which is pretty much perfect room) but as you've seen,I think you've got remarkable results from grey screen and wonder if ALR would give any added benefits further (for perceived contrast).
Lights off there’s no difference, Ricky sent me over samples of both for a mate to test in his place and I did the check before he collected them. ALR really comes into its own when there’s light in the room be that from actual lights or reflective but as I don’t have reflective light I think that’s why there’s zero difference.
 

alebonau

Active Member
That was my old white 16:9 screen, the grey 2.35:1 is on another level with regards to blacks.

View attachment 1382772
this is an interesting discussion, am surprised you went a grey screen ? havent you got a dedicated room or have I missed something ? I wouldn't have thought you'd go grey screen with the epson. I have helped two folk with the 9400... not to question no doubt some good advice you are getting from a specialist, but I would have thought you go grey screens more for something like the current crop "4k" DLPs that seem horrendous with contrast ?

Yup. I just wonder what ALR would do versus Grey. Interesting to think right.

The general concensus is that you use a white screen in a room like yours (which is pretty much perfect room) but as you've seen,I think you've got remarkable results from grey screen and wonder if ALR would give any added benefits further (for perceived contrast).
this does raise a good point though when comes to HDR and projectors what do grey screens do here for HDR ? do they I wouldn't have thought can increase dynamic range... instead shift the dynamic range to lower contrast ? but you give up pure whites ? for grey ? so do they do anything for HDR ?

what helps dynamic range and HDR ? the basic native contrast of the projector ? dynamic contrast caapabilties ? clearly tone mapping ability ? the room ! this is massive impact... I say this with a room some galaxies away from ideal ... but I can still see contrast difference between say epson to jvc x35 to say x7000, though didnt pick up so much x7000 to N7... ALR screen I would think impact a lot if less than ideal room or poor light control ?(obviously taking the limitations of ALR into account)

interesting stuff...I suspect with HDR given we are peak luminance limited with projectors, contrast is a bigger and more important factor and what we can help there will no doubt help with direct results with how well HDR and dynamic tone mapping works :)
 

bytehoven

Active Member
Manufactures can not support DV without a DV license, and last i looked DV would not license projectors.
When discussing projectors its a bit more complex, you have the guy with a 4m wide sound transparent screen getting 8fl on screen with a JVC NX9 and around 25000:1 contrast, or there is the other guy with the same projector who calibrated it to 20fl on a 2,4m wide screen with 60000:1 contrast, how can you build a tonemapping for these kinds of variations, and how will you as a creator make sure your creative intent is what these guys are watching?
Based on some conversations, I wonder if the lack of DV licensing for projectors is about the extremely low dynamic range limitations or something else.

Maybe LG with its market muscle, will be the 1st to bring a DV solution to their projectors.

Given how Sony already collaborated with Dolby on the profile 5 layer for player led tone mapping, they seemed like the natural candidate to do something with their projectors. I'm curious if product division autonomy within Sony, enables the projector group to continue down a different path? I really need to see the new X1 for Projectors DHDRE in action for myself, and see where the performance lies on the tone mapping continuum.
 

Luminated67

Distinguished Member
this is an interesting discussion, am surprised you went a grey screen ? havent you got a dedicated room or have I missed something ? I wouldn't have thought you'd go grey screen with the epson. I have helped two folk with the 9400... not to question no doubt some good advice you are getting from a specialist, but I would have thought you go grey screens more for something like the current crop "4k" DLPs that seem horrendous with contrast ?
I probably wouldn’t recommend a grey screen to a JVC because they already are high contrast projectors but for ones that are below 10k:1 it will boost the black levels as long as it has decent lumens to begin with, so in my opinion to be solely used by DLPs would be a waste. The benefits once up were obvious, I now can watch a movie with my spots on at 2% light output and still get a very decent experience but with lights off the blacks are truly amazing and not at the expense of shadow detail. If viewed in a dark room you’ll see the collar of the bouncer.

E753390C-C54C-40E4-AC79-906CCA67A7A8.jpeg


Ricky’s Diverse Screen reference grey material is light grey and it’s 0.9 gain so I’m losing very little on actual lumens and it’s colour balance is unaffected so very minor adjustments on brightness.

I’ve compared both pre and post grey screen with the S&M HDR disc and it altered the HDR slider on the Epson one click but obviously colours and blacks are more intense.

If you continuously chase the absolute best movie experience then you do two things, spend a sh*t load of money and never become satisfied with what you have.

Just remember why you got into home theatre....

.... to enjoy watching movies at home.:smashin:
 

panman40

Distinguished Member
I probably wouldn’t recommend a grey screen to a JVC because they already are high contrast projectors but for ones that are below 10k:1 it will boost the black levels as long as it has decent lumens to begin with, so in my opinion to be solely used by DLPs would be a waste. The benefits once up were obvious, I now can watch a movie with my spots on at 2% light output and still get a very decent experience but with lights off the blacks are truly amazing and not at the expense of shadow detail. If viewed in a dark room you’ll see the collar of the bouncer.

View attachment 1382975

Ricky’s Diverse Screen reference grey material is light grey and it’s 0.9 gain so I’m losing very little on actual lumens and it’s colour balance is unaffected so very minor adjustments on brightness.

I’ve compared both pre and post grey screen with the S&M HDR disc and it altered the HDR slider on the Epson one click but obviously colours and blacks are more intense.

If you continuously chase the absolute best movie experience then you do two things, spend a sh*t load of money and never become satisfied with what you have.

Just remember why you got into home theatre....

.... to enjoy watching movies at home.:smashin:
When I hold up the grey diverse sample against my white screen I do see a shift in colour balance ?.
 

panman40

Distinguished Member
Ay it's no-where near exciting enough in here, let's have some proper controversy. For fun I just picked up one of these D65 medialight kits and did this to my X7900. Thoughts?!?
View attachment 1382710
How are you finding the backlighting James ?. When I forget to turn off my tvs backlighting I find it really distracting but yours looks ok.
 

Luminated67

Distinguished Member
When I hold up the grey diverse sample against my white screen I do see a shift in colour balance ?.
Funny I don’t, is your room similar to mine?

If I have the lights on or even open the door into the next room so there’s some light entering the room I can see a shift which I put down to is superior ability to combat light but in total darkness look remarkably similar, the best way to describe it is more pop and intensity but the colour looks the same.
 

The latest video from AVForums

Podcast: The Best TVs and Projectors of 2020, plus AV, TV Show & Movie News & Reviews

Latest News

What's new on Sky and NOW TV UK for December 2020
  • By Andy Bassett
  • Published
What's new on Netflix UK for December 2020
  • By Andy Bassett
  • Published
Warner Bros 2021 movies coming to HBO Max and cinemas simultaneously
  • By Andy Bassett
  • Published
What's new on Disney+ UK for December 2020
  • By Andy Bassett
  • Published
4K Streaming impacts carbon emissions says Royal Society
  • By Andy Bassett
  • Published
Top Bottom