Forum Jump: 
 121Likes
Reply
 
Thread Tools
post #1 of 1078 Old 11-24-2017, 07:58 AM - Thread Starter
Senior Member
 
Join Date: Jul 2017
Posts: 225
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 197 Post(s)
Liked: 27
Cool Calibrating HDR on Epson 5040/6040 projectors

There have been some very good conversations past week or so on various other threads regards calibrating the Epson 5040/6040 for HDR.

These threads were...
http://01900888.com/forum/68-dig...rs-thread.html
http://01900888.com/forum/139-di...-software.html
http://01900888.com/forum/139-di...-3-thread.html

In an effort not to swamp those threads and possibly take them off topic, I have created this one.

Update:
To save yourself reading loads of pages, the current process (WIP) is post 344

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Cambridge Audio Minx Min21's & Min12's, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, LG 42LS575T, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite

Last edited by viperlogic; 01-20-2018 at 02:20 AM.
viperlogic is offline  
Sponsored Links
Advertisement
 
post #2 of 1078 Old 11-24-2017, 08:14 AM - Thread Starter
Senior Member
 
Join Date: Jul 2017
Posts: 225
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 197 Post(s)
Liked: 27
@Dominic Chan

Continuing from the latest discussion, could you expand further on your current thinking of what diffuse white and peak brightness to try aim for for best of possible HDR experience with a projector?

My current understanding is that diffuse white is 100 nits, anything above this are spectral highlights. Naturally projectors are not as bright as screens that can hit 100's to 1000's of nits so we have a limited range for these.

Currently on my 5040 I'm getting the following using the 50%/100% Masciola pattern...
BC HDR1 med = 21 nits
BC HDR1 high = 27 nits
Dynamic HDR1 med = 39 nits
Dynamic HDR1 high = 54 nits

And the with 100%/100% pattern...
BC HDR1 Med = 116 nits
BC HDR1 high = 150 nits
Dynamic HDR1 med = 188 nits
Dynamic HDR1 high = 248 nits



Am I right in saying you are recommending for diffuse white to be 50 nits therefore leaving headroom for highlights? What I'm struggling with is how does the projector know that 50 is the diffuse white and maps from that?

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Cambridge Audio Minx Min21's & Min12's, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, LG 42LS575T, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite
viperlogic is offline  
post #3 of 1078 Old 11-24-2017, 08:23 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by viperlogic View Post
@Dominic Chan

Continuing from the latest discussion, could you expand further on your current thinking of what diffuse white and peak brightness to try aim for for best of possible HDR experience with a projector?

<snip>
Am I right in saying you are recommending for diffuse white to be 50 nits therefore leaving headroom for highlights? What I'm struggling with is how does the projector know that 50 is the diffuse white and maps from that?
There is no HDR standard that applies to projectors, due to the much more limited peak luminance. What I suggested is to use half of the luminance, consistent with the SDR practice of calibrating to 50 nits white instead of 100 nits white.
This approach is similar to what Steve Shaw refers to as the "multifplier":
http://www.lightillusion.com/uhdtv.html
Dominic Chan is online now  
Sponsored Links
Advertisement
 
post #4 of 1078 Old 11-24-2017, 08:26 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by viperlogic View Post
There have been some very good conversations past week or so on various other threads regards calibrating the Epson 5040/6040 for HDR.

These threads were...
http://01900888.com/forum/68-dig...rs-thread.html
http://01900888.com/forum/139-di...-software.html
http://01900888.com/forum/139-di...-3-thread.html

In an effort not to swamp those threads and possibly take them off topic, I have created this one.
That's a good idea, although the links can be more specific to a page or post where this topic was discussed. HCFR thread has close to 10,000 post!
gene4ht likes this.
Dominic Chan is online now  
post #5 of 1078 Old 11-24-2017, 08:30 AM
AVS Forum Special Member
 
Light Illusion's Avatar
 
Join Date: Aug 2010
Posts: 1,540
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 580 Post(s)
Liked: 951
The 'Multiplier' approach is basically what Dolby use for their HDR projection based cinema, with their 103 nits projection configurations (I think it is 103 nits, without checking my data...).

To allow for different peak luminance we have a user definable multiplier within LightSpace to allow for user preferences.

(http://www.lightillusion.com/lut_ma...n_colour_space)

We also have a user definable tone-map, as varying the rolls-off is key for getting the best final result, rather than just relying on the fixes time mapping of BT2390.

As they say, every little helps!

Steve

Steve Shaw
LIGHT ILLUSION

Light Illusion is online now  
post #6 of 1078 Old 11-24-2017, 12:05 PM - Thread Starter
Senior Member
 
Join Date: Jul 2017
Posts: 225
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 197 Post(s)
Liked: 27
Sorry folks, I'm still struggling with the concept, maybe just one of those days/weeks! Also can't see mention of multiplier in the http://www.lightillusion.com/uhdtv.html article.

Maybe I just need a better understanding of how the HDR works. If a UHD is created against 1000 nits, how does a projector with say 100 to 150 peak nits use this data? Lets say theres a scene where a bunch of pixels need 500 nits, does the projector just use max, so in essence for a scene with various high nit pixels eg 300, 400, and 500, a projector with 150 will just show max for all of them so there is no definition between them if that is the right word. I'm an engineer by trade and I can't let things go until I understand how they work, to my own detriment! Thanks for your patience.

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Cambridge Audio Minx Min21's & Min12's, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, LG 42LS575T, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite
viperlogic is offline  
post #7 of 1078 Old 11-24-2017, 12:51 PM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by viperlogic View Post
Sorry folks, I'm still struggling with the concept, maybe just one of those days/weeks! Also can't see mention of multiplier in the http://www.lightillusion.com/uhdtv.html article.
http://www.lightillusion.com/hdr_calibration.html
viperlogic likes this.
Dominic Chan is online now  
post #8 of 1078 Old 11-24-2017, 01:19 PM
Advanced Member
 
jwhn's Avatar
 
Join Date: Dec 2013
Posts: 773
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked: 160
Quote:
Originally Posted by Dominic Chan View Post
There is no HDR standard that applies to projectors, due to the much more limited peak luminance. What I suggested is to use half of the luminance, consistent with the SDR practice of calibrating to 50 nits white instead of 100 nits white.
This approach is similar to what Steve Shaw refers to as the "multifplier":
http://www.lightillusion.com/uhdtv.html
Thanks for creating this thread!

Dominic, I've been following your lead on how to approach this for the 5040ub and already I really like the results.

The attached chart shows how my gamma is tracking to the targets that Zoyd provided (with some small adjustments down to 138 nits). Picture looks very good now and I don't have the issue with HDR being too dark.

But as you'll see, the main challenge is that my luminance is too low from 50% to 70%. Gamma settings are completely maxed out in these ranges. I can get these closer to the targets by increasing the contrast (currently set very low at 20) but then I start to see the whites getting crushed.

I used Ryan's white clipping pattern to set contrast to clip at 1000 nits (this is how I arrived at a low contrast of 20). Again, if I increase it I do start to see whites getting crushed.

Is this the right way to set contrast for HDR, knowing what I am trying to do with the 5040?

Any other suggestions to improve these results?
Attached Thumbnails
Click image for larger version

Name:	HDR tone mapping.png
Views:	213
Size:	78.7 KB
ID:	2320586  
jwhn is offline  
post #9 of 1078 Old 11-24-2017, 10:47 PM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by jwhn View Post
But as you'll see, the main challenge is that my luminance is too low from 50% to 70%. Gamma settings are completely maxed out in these ranges. I can get these closer to the targets by increasing the contrast (currently set very low at 20) but then I start to see the whites getting crushed.

I used Ryan's white clipping pattern to set contrast to clip at 1000 nits (this is how I arrived at a low contrast of 20). Again, if I increase it I do start to see whites getting crushed.

Is this the right way to set contrast for HDR, knowing what I am trying to do with the 5040?

Any other suggestions to improve these results?
I was able to get pretty close to the target curve (dotted yellow line) by keeping Contrast at 50, and reducing clipping using the top gamma control point. The target curve is for contents mastered on 1000-nit displays, but with a multiplier of about 50%.
I don't have Masciola's patterns, so all adjustments are based on HCFR's internal patterns and manually setting the mode to HDR1.
Attached Thumbnails
Click image for larger version

Name:	EOTF.jpg
Views:	213
Size:	241.9 KB
ID:	2320794  

Last edited by Dominic Chan; 11-24-2017 at 11:13 PM.
Dominic Chan is online now  
post #10 of 1078 Old 11-24-2017, 11:16 PM
Advanced Member
 
jwhn's Avatar
 
Join Date: Dec 2013
Posts: 773
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked: 160
Quote:
Originally Posted by Dominic Chan View Post
I was able to get pretty close to the target curve (dotted yellow line) by keeping Contrast at 50, and reducing the top gamma control point. The target curve is for contents mastered on 1000-nit displays, but with a multiplier of about 50%..
I don't have Masciola's patterns, so all adjustments are based on HCFR's internal patterns and manually setting the mode to HDR1.
That's great. Very close. I did another round tonight and improved my results. I am getting it pretty close. HDR content is really looking good now. Thanks for suggesting this approach.

Are you able to share your custom gamma settings and how you were able to track the target so closely?
jwhn is offline  
post #11 of 1078 Old 11-25-2017, 06:01 AM - Thread Starter
Senior Member
 
Join Date: Jul 2017
Posts: 225
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 197 Post(s)
Liked: 27
Quote:
Originally Posted by Dominic Chan View Post
That article certainly helped. Thanks

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Cambridge Audio Minx Min21's & Min12's, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, LG 42LS575T, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite
viperlogic is offline  
post #12 of 1078 Old 11-25-2017, 06:02 AM - Thread Starter
Senior Member
 
Join Date: Jul 2017
Posts: 225
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 197 Post(s)
Liked: 27
Quote:
Originally Posted by Dominic Chan View Post
I was able to get pretty close to the target curve (dotted yellow line) by keeping Contrast at 50, and reducing clipping using the top gamma control point. The target curve is for contents mastered on 1000-nit displays, but with a multiplier of about 50%.
I don't have Masciola's patterns, so all adjustments are based on HCFR's internal patterns and manually setting the mode to HDR1.
What settings in HCFR do you use to show/draw your target curve?

Also are you using extended video range and superwhite?

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Cambridge Audio Minx Min21's & Min12's, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, LG 42LS575T, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite
viperlogic is offline  
post #13 of 1078 Old 11-25-2017, 07:15 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by viperlogic View Post
What settings in HCFR do you use to show/draw your target curve?
HCFR does not let one edit the target curve, so I had to come up with the following trick:
  1. Convert the BT.2390 tone mapping values posted by @zoyd , to 0-100% range. I use the 300_8000 version. (Unfortunately I forgot to use the "8-bit simulation" so there's a small error.
  2. Create a blank HCFR file using Simulated Sensor, setting all simulation errors to 0.
  3. Run the Gray Scale sweep, Primary and Secondary Colours, Saturation Sweeps.
  4. In the Grey Scale grid, turn on Editable Data, and change all the Y values to the BT.2390 values . I use the 1000 nits version but you can also ues the 4000 nits version.
  5. For the 100% stimulus, override the Y with the peak white you're actually getting (141 in my case). Select Yes to scale all measurement.
  6. Save the file and select it as Reference which you can use as the target for the real measurement.

I have attached the spreadsheet, the Reference chc, and my own measurements chc for those who want to try the approach.

Quote:
Also are you using extended video range and superwhite?
No.
Attached Files
File Type: zip HP_C50_Custom.zip (26.7 KB, 95 views)
viperlogic likes this.
Dominic Chan is online now  
post #14 of 1078 Old 11-25-2017, 08:02 AM
AVS Forum Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 6,804
Mentioned: 144 Post(s)
Tagged: 0 Thread(s)
Quoted: 1783 Post(s)
Liked: 1340
zoyd is offline  
post #15 of 1078 Old 11-25-2017, 08:10 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by zoyd View Post
The curve has a different shape for 141 nits max white compared to 300 max so I don't think that linear scaling will work.
Yes, I understand that. I've explained my rationale in a previous post
http://01900888.com/forum/139-di...l#post55174284

BTW, when I said "too bright", that is for projector in a completely dark room, where people calibrate to 50 nits rather than 100 nits SDR.
Hence I asked for a 300 nits curve rathan than a 141 nits curve.

I believe the JVC projector users are doing something similar for ST2084, although they don't seem to be aware of the tone mapping standard in BT.2390. LightSpace is also using something similar, in terms of aiming for a lower luminance.

Last edited by Dominic Chan; 11-25-2017 at 08:27 AM.
Dominic Chan is online now  
post #16 of 1078 Old 11-25-2017, 08:20 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by jwhn View Post
That's great. Very close. I did another round tonight and improved my results. I am getting it pretty close. HDR content is really looking good now. Thanks for suggesting this approach.

Are you able to share your custom gamma settings and how you were able to track the target so closely?
I can certainly post the gamma settings later for you to try.
However, I find it very hard to "read back" the custom gamma settings on the Epson projectors. It displays the setting while you're adjusting it, but does not display the value when you're done (unless you start changing it again). It only displays a graphical curve which is very "rough". Did I miss something?
Dominic Chan is online now  
post #17 of 1078 Old 11-25-2017, 08:27 AM
AVS Forum Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 6,804
Mentioned: 144 Post(s)
Tagged: 0 Thread(s)
Quoted: 1783 Post(s)
Liked: 1340
ok, you can compare to this curve where I have shifted the knee parameter to give you ~50 nits at 50% stimulus. (actual 59 nits for 1000 nit master, 41 nits 4000 nit master)
Attached Files
File Type: txt 140_kneeshift.txt (48.8 KB, 76 views)
zoyd is offline  
post #18 of 1078 Old 11-25-2017, 08:32 AM
Advanced Member
 
jwhn's Avatar
 
Join Date: Dec 2013
Posts: 773
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked: 160
Quote:
Originally Posted by Dominic Chan View Post
I can certainly post the gamma settings later for you to try.
However, I find it very hard to "read back" the custom gamma settings on the Epson projectors. It displays the setting while you're adjusting it, but does not display the value when you're done (unless you start changing it again). It only displays a graphical curve which is very "rough". Did I miss something?
Yes, the gamma settings are a bit of a pain with the 5040. I don't need the exact settings. Maybe if you just take a picture of the curve for now. My situation is different given the luminance I get so I won't really be able to use your settings. I just wanted to see if it gave me any ideas.

Any tips on using the Epson gamma settings with HCFR? I think I read once that you set it up to do real-time adjustments.

A few other questions:
-
- I've just been experimenting for now to see if this approach actually produces a good result before spending too much time trying to get it precise. It seems as though it is going to work quite well. What is your opinion when looking at HDR content?


EDIT - I think Zoyd's new file addresses these questions. Thanks, Zoyd!

- When you scale the curve in HCFR (nice trick by the way), it also scales down the 0%. Wouldn't you want to leave 0% and maybe 5% at the original target? I can't hit 0.01 in my room.

- Looks like Zoyd verified that Ryan is actually using 10-bit codes rounded to whole numbers. So if I am using his disk, your scaled file is accurate, right?

Last edited by jwhn; 11-25-2017 at 08:52 AM.
jwhn is offline  
post #19 of 1078 Old 11-25-2017, 08:59 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by jwhn View Post
Yes, the gamma settings are a bit of a pain with the 5040. I don't need the exact settings. Maybe if you just take a picture of the curve for now. My situation is different given the luminance I get so I won't really be able to use your settings. I just wanted to see if it gave me any ideas.
I'll take a picture next time I turn on the projector (prefer not to cycle it on/off in a short time). From what I remember, I maxed out control C8 and turned down C9. C1 was untouched at 0, the others at slightly positive values.
[EDIT: Picture of Gamma Settings attached]

Quote:
Any tips on using the Epson gamma settings with HCFR? I think I read once that you set it up to do real-time adjustments.
Once you've decided on a specific contrast setting, you can characterize the controls by running sweeps maxing out one control at a time while keeping all the others at default. I've posted the values previously, but that was for SDR.
An alternative for Epson projectors is to display a pattern and ask the projector to show you which control corresponds to that stimulus.
Quote:
A few other questions:
- When you scale the curve in HCFR (nice trick by the way), it also scales down the 0%. Wouldn't you want to leave 0% and maybe 5% at the original target? I can't hit 0.01 in my room.
I requested zoyd to produce the curve for 300 nits peak and 8000:1 contrast ratio. The contrast ratio does not change when I scale down the values, so the black value after scaling is actually the right value I'm getting.
Quote:
- I've just been experimenting for now to see if this approach actually produces a good result before spending too much time trying to get it precise. It seems as though it is going to work quite well. What is your opinion when looking at HDR content?
To be honest, it was really late last night when I finished so I did not even have any chance to watch real HDR content. However, as I mentioned previously, the default HDR1 curve was already very good with a diffuse white of 40 nits. This curve reduces the highlight clipping.
[EDIT: I watched X-Men Apocalypse and noticed some clipping of extreme highlight. Not sure if that movie was mastered on 4000 nits or 1000 nits display]

Quote:
- Looks like Zoyd verified that Ryan is actually using 10-bit codes rounded to whole numbers. So if I am using his disk, your scaled file is accurate, right?
Yes.
Attached Thumbnails
Click image for larger version

Name:	Epson_HDR1_Gamma.jpg
Views:	261
Size:	482.9 KB
ID:	2320990  

Last edited by Dominic Chan; 11-25-2017 at 02:27 PM.
Dominic Chan is online now  
post #20 of 1078 Old 11-25-2017, 11:39 PM
Advanced Member
 
jwhn's Avatar
 
Join Date: Dec 2013
Posts: 773
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked: 160
Calibrating HDR on Epson 5040/6040 projectors

Quote:
Originally Posted by Dominic Chan View Post
I'll take a picture next time I turn on the projector (prefer not to cycle it on/off in a short time). From what I remember, I maxed out control C8 and turned down C9. C1 was untouched at 0, the others at slightly positive values.

[EDIT: Picture of Gamma Settings attached]





Once you've decided on a specific contrast setting, you can characterize the controls by running sweeps maxing out one control at a time while keeping all the others at default. I've posted the values previously, but that was for SDR.

An alternative for Epson projectors is to display a pattern and ask the projector to show you which control corresponds to that stimulus.



I requested zoyd to produce the curve for 300 nits peak and 8000:1 contrast ratio. The contrast ratio does not change when I scale down the values, so the black value after scaling is actually the right value I'm getting.



To be honest, it was really late last night when I finished so I did not even have any chance to watch real HDR content. However, as I mentioned previously, the default HDR1 curve was already very good with a diffuse white of 40 nits. This curve reduces the highlight clipping.

[EDIT: I watched X-Men Apocalypse and noticed some clipping of extreme highlight. Not sure if that movie was mastered on 4000 nits or 1000 nits display]





Yes.

Do you think Ryan's white clipping pattern would help you?

I guess the ideal would be to have 2 calibrations - one for each mastering display

Thanks for posting the pic of the gamma settings.




Sent from my iPhone using Tapatalk
jwhn is offline  
post #21 of 1078 Old 11-26-2017, 06:42 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by jwhn View Post
Do you think Ryan's white clipping pattern would help you?
It's hard to say. Ryan's patterns are for 1000-nit masters, and will not resolve patch 723 (75.2%) and above. Looking at zoyd's tone mapping curves, 4000-nit masters can go all the way up to about 83%.
http://01900888.com/forum/139-di...l#post55181272
Quote:
I guess the ideal would be to have 2 calibrations - one for each mastering display
Yes, the question being whether we can achieve the higher clipping with the limited adjustability of the 5040UB.
I've added an HCFR feature request to have the current Near White scale made adaptive, to measure HDR clipping. For SDR, I find the Near White pattern easier to use than flashing clipping patterns.

Last edited by Dominic Chan; 11-26-2017 at 06:52 AM.
Dominic Chan is online now  
post #22 of 1078 Old 11-26-2017, 07:22 AM - Thread Starter
Senior Member
 
Join Date: Jul 2017
Posts: 225
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 197 Post(s)
Liked: 27
Just noticed my black is poor eg .11 nits. My env is a dark room with no ambient light. I see others have much better "black" eg Dominic has 0.019. What could be causing this? Possible light leakage within the projector or ? Because of this I have v poor contrast ratio, approx 1:1000.

Edit: Think that was with iris off. Will have to check what it is with iris on. Am I right in saying all calibration should be done with iris off, and then when calibration is complete turn it on? Dominic, you getting 0.019 with iris off?

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Cambridge Audio Minx Min21's & Min12's, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, LG 42LS575T, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite

Last edited by viperlogic; 11-26-2017 at 07:50 AM.
viperlogic is offline  
post #23 of 1078 Old 11-26-2017, 08:01 AM
AVS Forum Special Member
 
Join Date: Dec 2014
Location: Mississauga, ON, Canada
Posts: 5,404
Mentioned: 85 Post(s)
Tagged: 0 Thread(s)
Quoted: 3708 Post(s)
Liked: 1149
Quote:
Originally Posted by viperlogic View Post
Think that was with iris off. Will have to check what it is with iris on. Am I right in saying all calibration should be done with iris off, and then when calibration is complete turn it on? Dominic, you getting 0.019 with iris off?
Yes and yes.
Try measuring with the meter facing the projector lens, diffuser on. This provides a more accurate measure of the contrast ratio, based on which you can deduce the black level nits.
viperlogic likes this.
Dominic Chan is online now  
post #24 of 1078 Old 11-26-2017, 10:33 AM
Advanced Member
 
jwhn's Avatar
 
Join Date: Dec 2013
Posts: 773
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked: 160
Quote:
Originally Posted by Dominic Chan View Post
It's hard to say. Ryan's patterns are for 1000-nit masters, and will not resolve patch 723 (75.2%) and above. Looking at zoyd's tone mapping curves, 4000-nit masters can go all the way up to about 83%.
http://01900888.com/forum/139-di...l#post55181272

Yes, the question being whether we can achieve the higher clipping with the limited adjustability of the 5040UB.
I've added an HCFR feature request to have the current Near White scale made adaptive, to measure HDR clipping. For SDR, I find the Near White pattern easier to use than flashing clipping patterns.
I believe he has added some support for 4000-nit masters. See the attached pattern. He has also added full grey scale patterns at 4000 and 10,000 nits. By the way, here is a link to another set of free HDR patterns. I haven't tried them yet. http://yadi.sk/d/RPrX2C7l3HEjPq
Attached Thumbnails
Click image for larger version

Name:	IMG_6088.jpg
Views:	136
Size:	674.2 KB
ID:	2321350  
jwhn is offline  
post #25 of 1078 Old 11-26-2017, 10:38 AM
Advanced Member
 
jwhn's Avatar
 
Join Date: Dec 2013
Posts: 773
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked: 160
Quote:
Originally Posted by zoyd View Post
ok, you can compare to this curve where I have shifted the knee parameter to give you ~50 nits at 50% stimulus. (actual 59 nits for 1000 nit master, 41 nits 4000 nit master)
Thanks for this Zoyd.

For some of us, hitting 59 nits at 50% stimulus won't be possible. It's a challenge in my case to even get to 50 nits. Is it possible to force both the 1,000 and 4,000 curves to hit 47 nits more precisely while maintaining the max luminance target of 141?
jwhn is offline  
post #26 of 1078 Old 11-26-2017, 01:16 PM
AVS Forum Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 6,804
Mentioned: 144 Post(s)
Tagged: 0 Thread(s)
Quoted: 1783 Post(s)
Liked: 1340
Quote:
Originally Posted by jwhn View Post
Thanks for this Zoyd.

For some of us, hitting 59 nits at 50% stimulus won't be possible. It's a challenge in my case to even get to 50 nits. Is it possible to force both the 1,000 and 4,000 curves to hit 47 nits more precisely while maintaining the max luminance target of 141?
With 1000 nit master the lowest you can get the 50% value to go is about 58 nits. I'm adding the calculations to HCFR so you'll be able to do them on your own.
viperlogic likes this.
zoyd is offline  
post #27 of 1078 Old 11-26-2017, 01:33 PM
Advanced Member
 
jwhn's Avatar
 
Join Date: Dec 2013
Posts: 773
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked: 160
Quote:
Originally Posted by zoyd View Post
With 1000 nit master the lowest you can get the 50% value to go is about 58 nits. I'm adding the calculations to HCFR so you'll be able to do them on your own.
Got it. I was afraid you might say that. ; )

Do you have an ETA for the next version of HCFR?
jwhn is offline  
post #28 of 1078 Old 11-26-2017, 02:36 PM
AVS Forum Special Member
 
zoyd's Avatar
 
Join Date: Sep 2006
Location: Planet Dog
Posts: 6,804
Mentioned: 144 Post(s)
Tagged: 0 Thread(s)
Quoted: 1783 Post(s)
Liked: 1340
zoyd is offline  
post #29 of 1078 Old 11-26-2017, 02:38 PM
Senior Member
 
Join Date: Jul 2017
Posts: 346
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Liked: 202
Great thread

Thanks for this thread
Uppsalaing is offline  
post #30 of 1078 Old 11-26-2017, 03:02 PM - Thread Starter
Senior Member
 
Join Date: Jul 2017
Posts: 225
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 197 Post(s)
Liked: 27
Quick update, reset my BC profile to defaults, iris off, high lamp, left contrast at 50, brightness to 52, dialled in grayscale (peak of 148 nits), used Dominics method above to dial in luminance, then did my 50/50 sweep and calibration across the 6 colours using auto generated patterns casted via nvidia sheild. When done the picture looked terrible! Most colours blown. Spun up Ryans disk and put a 50/50 red pattern on the screen and it was seen that the colours calibrated using the generated patterns were miles off. Eg ryans 50/50 pattern was landing on the 75! HCFR was set to 2020/P3. Should HCFR (3.4.5.1) be sending the same patterns as Ryans eg when colour space is set to 2020/P3 eg 50 sat free measure and generated patterns is sending a 50/50 or actually is sending a 50/75? I'm thinking the later the way the colours are lining up.

Currently redoing the colours using Ryans disk. While I can dial in the hue and sat using the CIE digram, how will I dial in the 3rd dimension, brightness, as appears HCFR is off showing the delta luminance for that sat?

Epson EH-TW7300, 104" borderless ReAct 3, Denon AVR-X2300W in 5.1.2, Cambridge Audio Minx Min21's & Min12's, Monitor Audio Pro-65, BK P12-300 sub, Nvidia Shield, Vero 4K, Panasonic UB400, SKY Q, PS3, Wii, RPi, LG 42LS575T, Denon Heos soundbar, Amazon Echo, Logitech Harmony Elite

Last edited by viperlogic; 11-26-2017 at 03:12 PM.
viperlogic is offline  
Sponsored Links
Advertisement
 
Reply Display Calibration



Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off