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Manual gamma controls?

How do the manual gamma controls work? I tried tweaking them for the first time (ever) and they didn't update as I thought they would. I would change 95% and then I'd get the hour-glass icon for about 5 second while it supposedly communicated with the pj, but when i remeasured there was no change. Then it looked like I could it Save to save to a file, to then import? So does that mean the changes I made do not take effect until Saved and then reloaded and used as an Imported curve? In which case how can you interactively figure out what value to change something do without going through a full Save/re-import cycle? Seems like that would take forever. For instance I would like to try and drop that gamma spike at 95% (around 2.3 or 2.35) down to 2.2... Thanks.
 

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Real time adjustments work just fine using the JVC software and any meter. Set Gamma on the projector to Custom 1, Custom 2, or Custom 3 and then select Import as your Correction Value (pg 38 of the manual). Now when you make a change in the JVC software it can immediately be measured using your Klein and CalMAN 5. After every change at each gamma point, it does take about 15 seconds for the change to be sent to the PJ.

To use imported profiles, you also need to have Import as your Correction Value.

The gamma correction workflow is almost the same as with the older JVC projectors. However, now you need to use the software for multi point gamma correction instead of using the JVC menu. Once you get used to it, it doesn't take that long to get an excellent gamma curve.
Thanks! I was wondering if you or someone else can elaborate on this a bit more. I played around with the manual gamma controls in the autocal software for the first time last night and it was not intuitive as to how the controls were working. I am very familiar with using RGBW to manually adjust 11 point gamma (like in the old JVC projectors), just wasn't sure about how the autocal software itself was interacting with the pj.

When I first go into the gamma controls it gives me an option to select gamma 1, 2 or 3. Its blank to start with. For the correction value field in the autocal software, that is blank too, with the various options in there. I think the key point I was missing was the the gamma in the projector menu must be set on Import for any changes made in the software to be seen? That's not very intuitive (then again, what about the autocal is intuitive! :) ) because I wasn't using an imported curve.

So let's see if I have this straight...

1. Select the gamma in the JVC menu I want to use. Say Custom Gamma 1.
2. Set the correction value in the JVC gamma menu to Import (so now I have Custom Gamma 1 with a correction value of Import set in the JVC menu).
3. Run the autocal program and go into the Gamma section.
4. From the gamma menu in the autocal software, select the same custom gamma that I picked in step 1, in this case Custom Gamma 1.
5. From the Correction value in the autocal software, pick the BASELINE gamma I want to use for my manual tweaks. For instance if I want to make a BT1886 gamma I should pick 2.4 to work off of that as a baseline. If I want to tweak a 2.2 gamma, pick 2.2 here. Do I have this right??
6. Use the WRGB controls to make the desired changes at the various 5% step levels. Each time I do this I should be able to measure the change using CalMAN and my i1D3 running on a different laptop than the autocal, just to make it so I don't have to go back and forth between the autocal and CalMAN application.
7. Once I am done, I assume I have to hit the Save button? That would make sense. But then again seems a bit confusing since the software is making realtime changes I would think the data is already loaded?

Is the above accurate?

Also - let's say that with picture tone +2 and dark level +3 I am 90% of the way to a good BT1886 curve but just need to tweak a couple of points. Is there anyway to use THAT +2/+3 curve as my baseline and tweak that? Just wasn't sure if I am able to someone export that and then tweak it and put it back, rather than tweaking a straight 2.4 baseline curve manually.

Lastly, how do you export a gamma curve? So that I can distribute my custom HDR curve for low light setups? Manni explained it a week or two ago but I still cannot find any Export option in the gamma menu, which is what I think he said to use. Unless its the case that whatever curve you have loaded in the Import section is actually exported when you hit the Save button - and what they mean by Save is that it is SAVE to your PC and not SAVE to the projector... which now that I think about it must be the case.
 

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Thanks! I was wondering if you or someone else can elaborate on this a bit more. I played around with the manual gamma controls in the autocal software for the first time last night and it was not intuitive as to how the controls were working. I am very familiar with using RGBW to manually adjust 11 point gamma (like in the old JVC projectors), just wasn't sure about how the autocal software itself was interacting with the pj.

When I first go into the gamma controls it gives me an option to select gamma 1, 2 or 3. Its blank to start with. For the correction value field in the autocal software, that is blank too, with the various options in there. I think the key point I was missing was the the gamma in the projector menu must be set on Import for any changes made in the software to be seen? That's not very intuitive (then again, what about the autocal is intuitive! :) ) because I wasn't using an imported curve.

So let's see if I have this straight...

1. Select the gamma in the JVC menu I want to use. Say Custom Gamma 1.
2. Set the correction value in the JVC gamma menu to Import (so now I have Custom Gamma 1 with a correction value of Import set in the JVC menu).
3. Run the autocal program and go into the Gamma section.
4. From the gamma menu in the autocal software, select the same custom gamma that I picked in step 1, in this case Custom Gamma 1.
5. From the Correction value in the autocal software, pick the BASELINE gamma I want to use for my manual tweaks. For instance if I want to make a BT1886 gamma I should pick 2.4 to work off of that as a baseline. If I want to tweak a 2.2 gamma, pick 2.2 here. Do I have this right??
6. Use the WRGB controls to make the desired changes at the various 5% step levels. Each time I do this I should be able to measure the change using CalMAN and my i1D3 running on a different laptop than the autocal, just to make it so I don't have to go back and forth between the autocal and CalMAN application.
7. Once I am done, I assume I have to hit the Save button? That would make sense. But then again seems a bit confusing since the software is making realtime changes I would think the data is already loaded?

Is the above accurate?

Also - let's say that with picture tone +2 and dark level +3 I am 90% of the way to a good BT1886 curve but just need to tweak a couple of points. Is there anyway to use THAT +2/+3 curve as my baseline and tweak that? Just wasn't sure if I am able to someone export that and then tweak it and put it back, rather than tweaking a straight 2.4 baseline curve manually.

Lastly, how do you export a gamma curve? So that I can distribute my custom HDR curve for low light setups? Manni explained it a week or two ago but I still cannot find any Export option in the gamma menu, which is what I think he said to use. Unless its the case that whatever curve you have loaded in the Import section is actually exported when you hit the Save button - and what they mean by Save is that it is SAVE to your PC and not SAVE to the projector... which now that I think about it must be the case.
It is the case and it is what I told you a while ago. No gamma export in the export/import menu, only save from the gamma menu.

It's already in the PJ as all your changes are done in real-time (provided the import value is selected), the save menu only saves the content of the custom gamma import into a file, so you can share or import it later.

There is no difference between curves imported into the pj with Arve's tool and the ones you'll generate with the gamma menu. If you touch an existing custom curve, you'll lose some of the resolution and then all but 11points when you save it. It's the same table used both ways, just Arve's tool uses all 256 points and the JVC gamma/save/import only uses 11 points.

There are quite a few posts about using the gamma controls linked to in the first post of this thread.
 

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It is the case and it is what I told you a while ago. No gamma export in the export/import menu, only save from the gamma menu.

It's already in the PJ as all your changes are done in real-time (provided the import value is selected), the save menu only saves the content of the custom gamma import into a file, so you can share or import it later.

There is no difference between curves imported into the pj with Arve's tool and the ones you'll generate with the gamma menu. If you touch an existing custom curve, you'll lose some of the resolution and then all but 11points when you save it. It's the same table used both ways, just Arve's tool uses all 256 points and the JVC gamma/save/import only uses 11 points.

There are quite a few posts about using the gamma controls linked to in the first post of this thread.
Thanks. Are my steps 1-7 and assumptions there correct? If so it may be useful for others if you link to this in the first post. The links I found there were helpful but a little vague.
 

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It's already in the PJ as all your changes are done in real-time (provided the import value is selected), the save menu only saves the content of the custom gamma import into a file, so you can share or import it later.
Is this true for Autocal itself as well? I was under the impression that the Autocal result needs to be saved or else it will be gone when you shut down the projector.
 

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Is this true for Autocal itself as well? I was under the impression that the Autocal result needs to be saved or else it will be gone when you shut down the projector.


This is only for the manual gamma control, not for the Autocal.


The "save" option in the gamma menu doesn't save anything in the projector (it's already been saved), it only saves a file that can then be shared/imported.


It's not a bad idea to save your gamma curve before doing any changes (unless you already have it saved or if you're using Arve's tool to create it), otherwise there is no way back after manual changes.
 

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Gamma droop

@Manni01 and all - I'm continuing to struggle with autocal for some reason. Look at the gamma droop starting at 85%. This is what I measured tonight after just having done an autocal yesterday. I did not have the droop yesterday after doing autocal on these presets so I wonder if something I am doing such as playing with the custom gamma curves imported via Arve's tool is somehow upsetting the autocal gamma??

Here's what I did yesterday:
- CMD Low (I always have this setting), Standard color profile, iris -6, lamp high (always), color temp 6500K, gamma Normal
- user mode 2 selected
- with those above settings I ran an autocal gamma 33 step + color
- changed color profile to Rec709NF
- ran color only profile
- made custom color profile, switched to it. No gamma drooop in fact gamma overshot 2.2 at the top end as you can see in the results in my post from yesterday above.

- Then I switched the color profile to Reference and user mode 2 and ran a autocal gamma+color
- Then switched to BT2020 and ran color only
- Then made a custom color profile for BT2020

- Today I turned on the pj, selected user mode 2 with same settings (6500K, Normal gamma, lamp high, CMD low, iris -6)
- When I measured this I got the gamma droop. I measured against my custom rec709 color profile, the Rec709NF and even Standard and they all show the droop.

I'm thinking that something I am doing when I move on to the BT2020 autocal is undoing/setting the previous autocal back to the defaults? Or perhaps importing my gamma curves via Arve's Tool is resetting things. Something is causing the gamma droop fix from the autocal to disappear and I am back to having the droop. This is especially confusing because I've followed this procedure many times in month's past and don't recall having droop afterward. And after the autocal I have a straight diagnonal line in the autocal software. Then again I wasn't using CalMAN to measure the gamma afterward so I was just trusting that it worked, I suppose.

Do you see anything wrong with my procedure above? Any idea why this is happening? This is concerning because we all know that droop really impacts the PQ. Thanks!
 

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- Today I turned on the pj, selected user mode 2 with same settings (6500K, Normal gamma, lamp high, CMD low, iris -6)
- When I measured this I got the gamma droop. I measured against my custom rec709 color profile, the Rec709NF and even Standard and they all show the droop.
Are the two sets of measurements taken with the same projector settings? They have very different values for Max cd/m2 - 66.3 vs 39.9.
 

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Are the two sets of measurements taken with the same projector settings? They have very different values for Max cd/m2 - 66.3 vs 39.9.
Thanks for the response. I'm really not sure what is going on there or how that happened. I'm sure the zoom position was the same. I am going to start over completely from scratch (literally for about the 8th time in two days) and take careful notes along the way. There has been some really strange behavior with the autocal lately. For instance according to my i1D3 off the screen, compared to the Spyder 5 facing the pj, showed the autocal was quite short on blue for 60-100%. I've never seen that before following the same procedure as I'm following here.

A few clarifications please:

1. How important is it to turn off clear black and motion enhance? I always have those on Low in all my user modes and use cases. And I don't think I ever calibrated with them off. But I've seen a few references lately in this thread (Manni and Chad) saying to turn them off. Can this really mess things up or is that more of a "just in case" recommendation? So turn them off for gamma+color autocal even if I will use these on Low? What do you use for these settings?

2. When I watch the Log screen during the autocal, I notice that even in the "after calibration" log, all the measures for gray are fairly off. Like usually it shows that gray measures (at various % levels) around 0.317, 0.338, +/- about 0.002. This is relatively far off from the 0.313, 0.329 target for D65. The plot points all wind up within the D65 target "circle" shown in the autocal results window, but the resulting color temp shown in the little table at the end of the autocal shows the average color temp of around 6200K. Do you see this as well? This surprises me because even if the Spyder 5 is not very accurate, I would think that the software would still tune it closer to 0.313, 0.329, even if the real color temperature did not match what the Spyder 5 measured (due to its inaccuracy). And yes, during the beginning of the autocal it does not show any dashes next to things like color or gamma, so I know it is not skipping any steps like it would if a preset color temp or preset gamma was not selected.

3. Chad mentions using Natural, but I don't think that is not necessary as long as we have all the presets right and use Standard for Rec709 calibration and Reference for BT2020 calibration right?

4. Does the zoom position of the lens matter? I haven't seen this talked about at all. For instance for one user mode HDTV 16:9 viewing I have the zoom position set one way, and for another user mode I have it zoomed out for watching 2.40 movies.

Thanks!
 

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Color temp not improved after autocal

Why is autocal not really correcting my color temp? I'm running a gamma+color autocal with the following presets:

User mode: User 2
Color profile: Standard
Color temp: 6500K
Gamma: Normal

Please have a look at the log-before and log-after screens attached. Look at the gray measures 12%-100% before and compare them to aftxer. They are just barely changed. I also included the after screen showing the dot plot

I realize the Spyder 5 may not be fully accurate, but I would think it the autocal would at least think it was and the measurements would be closer to 0.313, 0.329 for each. Whereas they are not really that close.

Is this normal and the same type of results you guys get in terms of the "after" not being close to D65 at each point as one would expect, or is something not getting corrected or working for the color temp adjustment as expected? I know this can be tweaked with a custom color profile, but I was expecting it to get closer on its own. No? Thanks!

Edit: I was just looking at an autocal after-result from @Manni01 as posted at the beginning of this thread. Have a look at his result here: http://www.avsforum.com/forum/attachment.php?attachmentid=1119778&d=1450104093 . See how his D65 grouping is very tight and the finished color temp is very close to 6500? THAT is what I am expecting to see. Compare that to my before and after log - it didn't seem to really even touch it. :confused:
 

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Autocal not correcting gamma droop

Continuing from my message yesterday - I started over from scratch (again and again). After autocal I still have gamma droop. I can fix it with the manual gamma control. But of course the issue with that is then its only fixed for one imported curve and any other gammas I select including 2.4 or HDR custom curves will be off, not benefiting at all from that manual touchup.t C

Notice too that the gamma line shown in the after-results in the autocal software is straight - indicating no gamma droop. But CalMAN shows a very different story....

I'm at a complete loss and have spent over 20 hours in the past two days trying to figure this out with no progress. Between this and the color temp not adjusting (per the last post above) I am at a new level of calibration misery and frustration. :mad: I could REALLY use some help here please guys. At this point all I want to do is watch a movie already! :eek:

Here are the conditions which I ran a 33 point gamma + color autocal:

Autocal check list:

- Correct User mode selected HDHIGH
- Color profile: Standard (for Rec709)
- Lens zoomed to fill my 2.37 scoped screen
- Color Temp: 6500K
- Gamma: Normal
- Contrast/Brightness: set to 0
- Lamp: High
- Iris: 0
- CMD: Low
- Motion Enhance: Off
- Clear black: Off
- Lens aperture: Manual
- Iris position: 0

After that 33 point gamma + color I measured the grayscale. You can see the droop in the CalMAN results. I included a screen pic of how things looked after a manual touchup, proving the droop can be fixed manually. So why isn't autocal handling this for me? :confused:

I also included how the dE's clean up pretty nice with the custom color profile, again with the manual gamma touch up included. Also included are the various screens of the autocal - perhaps I am doing something totally stupid here, but at any rate I'd certainly appreciate some advice!

The main problem is illustrated in try2-autocal-results-gamma.png. Spyder 5 used during the auotcal, i1D3 meter used facing the screen for all CalMAN results.

Note that because the JVC lamp seems pretty unstable at 90-100% I used Manni's trick of setting the low lamp threshold to 9999 ftL and max exposure on the i1D3 to 5 seconds. This helps to smooth out the unstable-ish lamp and gave more consistent readings.

Please don't be mislead by the last two pics - as labeled in the file name "MANUAL" those were done using the manual gamma touch up. The question is why isn't the autocal doing better than shown with this droop shown in try2-autocal-results-gamma.png.

Note that the measurements are taking with the same EXACT settings as used for the calibration (I'm going straight from the autocal into measuring, not changing the iris position or lamp or CMD or color profile, etc) except for the one that shows how things look with the manual gamma curve in which case the only change there was selecting Custom 1 Import gamma.

Please review the screens and let me know what you think. Thank you!
 

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Continuing from my message yesterday - I started over from scratch (again and again). After autocal I still have gamma droop. I can fix it with the manual gamma control. But of course the issue with that is then its only fixed for one imported curve and any other gammas I select including 2.4 or HDR custom curves will be off, not benefiting at all from that manual touchup.t C

Notice too that the gamma line shown in the after-results in the autocal software is straight - indicating no gamma droop. But CalMAN shows a very different story....

I'm at a complete loss and have spent over 20 hours in the past two days trying to figure this out with no progress. Between this and the color temp not adjusting (per the last post above) I am at a new level of calibration misery and frustration. :mad: I could REALLY use some help here please guys. At this point all I want to do is watch a movie already! :eek:

Here are the conditions which I ran a 33 point gamma + color autocal:

Autocal check list:

- Correct User mode selected HDHIGH
- Color profile: Standard (for Rec709)
- Lens zoomed to fill my 2.37 scoped screen
- Color Temp: 6500K
- Gamma: Normal
- Contrast/Brightness: set to 0
- Lamp: High
- Iris: 0
- CMD: Low
- Motion Enhance: Off
- Clear black: Off
- Lens aperture: Manual
- Iris position: 0

After that 33 point gamma + color I measured the grayscale. You can see the droop in the CalMAN results. I included a screen pic of how things looked after a manual touchup, proving the droop can be fixed manually. So why isn't autocal handling this for me? :confused:

I also included how the dE's clean up pretty nice with the custom color profile, again with the manual gamma touch up included. Also included are the various screens of the autocal - perhaps I am doing something totally stupid here, but at any rate I'd certainly appreciate some advice!

The main problem is illustrated in try2-autocal-results-gamma.png. Spyder 5 used during the auotcal, i1D3 meter used facing the screen for all CalMAN results.

Note that because the JVC lamp seems pretty unstable at 90-100% I used Manni's trick of setting the low lamp threshold to 9999 ftL and max exposure on the i1D3 to 5 seconds. This helps to smooth out the unstable-ish lamp and gave more consistent readings.

Please don't be mislead by the last two pics - as labeled in the file name "MANUAL" those were done using the manual gamma touch up. The question is why isn't the autocal doing better than shown with this droop shown in try2-autocal-results-gamma.png.

Note that the measurements are taking with the same EXACT settings as used for the calibration (I'm going straight from the autocal into measuring, not changing the iris position or lamp or CMD or color profile, etc) except for the one that shows how things look with the manual gamma curve in which case the only change there was selecting Custom 1 Import gamma.

Please review the screens and let me know what you think. Thank you!
I am sorry I cannot help you much with your difficulties...but I just want to chime in and warn new users: do not blindly trust what autocal does...I believe Manni was very lucky to obtain such reference results using only the autocal software.

In my case, autocal nicely corrects my gamma curve, but by doing so, clearly makes my color temps worse and my gamut a lot worse (visible by the eye ane easily measured in Chromapure). I am working very hard trying to find why does autocal makes my color gamut a LOT worse. The color temp, I can fix manually, just like you manage to fix your gamma manually. But the worsened color gamut, I cannot.

I sorely regret selling my Radiance, believing that autocal would make it useless. But that is far from the truth.

So, I would strongly suggest not to use the autocal software without another way to verify what it really does with another software and probe. Many posts in this thread support this. It might be user error most of the time, but still, autocal can clearly make things worse.
 

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Two things:

1) Your second screenshot says "skip color". Have you checked that gamma+color was selected in the settings, and not only gamma?
2) Are you following Chad's procedure (or my modified version)? You need to correct the errors in your spyder. Please try running the autocal following either procedure to the letter, and report back. My understanding was that you were getting very good results that way.

You've been experimenting a lot recently to try to improve on errors of 0.5 to 1.5dE which are not meaningful without a reference meter, or using the high bright preset which leads to huge manual corrections (again, I advised against that: you want to select 6500K and make NO manual corrections after the autocal, especially without a reference meter).

This means that it used to work before you entered that rabbit hole of brightness and invisible, non-confirmed errors "optimisation". You've also tried things that don't work (like selecting another preset than 6500K during the autocal, which isn't recommended at all). So this setback is your punition for not sticking to the program :)

Get back to the recommended procedure, check your options, check your meter placement, correct your spyder errors and measure again. If it's still not working, something is defective or there is a wrong step somewhere.
 

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Two things:

1) Your second screenshot says "skip color". Have you checked that gamma+color was selected in the settings, and not only gamma?
That is only because that is the output for a "log only" calibration I ran after the fact, to show what the x,y readings were. That is to prove my point that compared to the pre-measurments it hadn't done anything to correct the grayscale (because in the screenshot before it you can see the x,y pre-measurements). For the gamma+color calibration itself you can see here http://www.avsforum.com/forum/attachment.php?attachmentid=2041841&d=1490159683 that there are no "-" markings which means the setup is good and it did not skip any steps during the gamma+color (I watched it).

2) Are you following Chad's procedure (or my modified version)?
Yes, for sure. In fact in the last screenshots you can see my dE after the custom color profile and there are all improved to under dE of 2 (compared to 4ish without the custom color profile).

You need to correct the errors in your spyder. Please try running the autocal following either procedure to the letter, and report back.
As far as I know I am following the procedure to the letter. I even turned off motion enhance and clear black because you guys said to, even tho I never did this in the past.

I used all the proper starting presets so that nothing would be skipped. I then ran a gamma 33+color. Gamma droop checked and present afterward. Then switched from Standard to Rec709NF. Then ran a color only autocal. Gamma droop measures the same. Then created a custom color profile. dE's dropped considerably and measure great (as does the gamut and color checker all within dE of 0.5 or lower!) but the droop of course is still present. :mad:

To confirm, you can see my initial setup screen here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041857&d=1490159719

When it starts running, you can see that it is set to correct everything (not dashes) in this screen here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041841&d=1490159683

On the results graphs you can see it SAYS my gamma curve was fixed as shown by the straight line here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041865&d=1490159752

But in reality it is NOT fixed and I have considerable gamma droop, as shown when measured in CalMAN here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041897&d=1490159983 . This was manually correctable in just 15 minutes. But the bigger issues is not the extra 15 minutes but rather that the internal gamma is still off except for this manual curve, so all other curves like 2.4 or even custom imported curves will be affected by the droop.

You can see that the grayscale was not adjusted either, as seen here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041881&d=1490159769 which compared to yours in post #2 mine is a very messy (yours was a much tighter D65 grouping). I posted specifically about this here: http://www.avsforum.com/forum/24-di...-x5000-rs400-rs500-rs600-55.html#post51683329

Have I missed anything?

My understanding was that you were getting very good results that way.
In the past, I never had measured my results with CalMAN afterward. I was just blindly trusting that the autocal fixed the gamma droop because of the straight gamma line it would show afterward, while the "before" line would sometimes be bowed downward. Here it shows me a perfectly straight gamma vs reference gamma line, but CalMAN shows there is really a droop. Oh and BTW, yes, I am hitting Save after the autocal procedures. :)

You've been experimenting a lot recently to try to improve on errors of 0.5 to 1.5dE which are not meaningful without a reference meter, or using the high bright preset which leads to huge manual corrections (again, I advised against that: you want to select 6500K and make NO manual corrections after the autocal, especially without a reference meter).

This means that it used to work before you entered that rabbit hole of brightness and invisible, non-confirmed errors "optimisation". You've also tried things that don't work (like selecting another preset than 6500K during the autocal, which isn't recommended at all). So this setback is your punition for not sticking to the program :)

Get back to the recommended procedure, check your options, check your meter placement, correct your spyder errors and measure again. If it's still not working, something is defective or there is a wrong step somewhere.
No - just to confirm, NONE of this has anything to do with eeking out brightness. My intention was to do a fresh autocal and get a great, clean starting point. And THEN do crazy stuff with the gains and High Bright and experiment to see what I could get. However I never got that far, because these attempts at a clean, normal autocal as a baseline for such experiments had these issues. So I've only done the gamma+color and then color only autocals as would normally be done. I'm still in 6500K with no RGB gains/offsets, still at Gamma Normal, etc. Yes I have the droop.

The custom color profile nicely takes care of the color temp issues (although it is still a mystery as to why autocal is not making ANY changes to the grayscale even if it thinks they are right and actually wrong due to Spyder 5, but in my case its not even improving them as far as the Spyder 5 is concerned, as covered above). The big concern is the gamma droop.

I feel like I have dotted every i, and crossed every t. I've been through the procedure at least two dozen times in the past couple of days. Same results each time. What could I be missing? :confused: I feel like I've gone back to the basics as much as possible and tried from scratch over and over, yet nothing changes. What would you recommend I do as far as trying to find the issue? The most basic thing I can do is an autocal with gamma+color and then measure immediately after without touching ANYTHING, which I've done, and shows the same gamma droop.

Thank you!!
 

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Continuing from my message yesterday - I started over from scratch (again and again). After autocal I still have gamma droop. I can fix it with the manual gamma control. But of course the issue with that is then its only fixed for one imported curve and any other gammas I select including 2.4 or HDR custom curves will be off, not benefiting at all from that manual touchup.
I'm not sure if the problem is with autocal. Your previous posts indicated that you were measuring both gamma spike and gamma droop, without re-running autocal. BTW, did you change the Super White setting?
Have you tried restoring the INIT calibration to see if gamma droop?
 

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That is only because that is the output for a "log only" calibration I ran after the fact, to show what the x,y readings were. That is to prove my point that compared to the pre-measurments it hadn't done anything to correct the grayscale (because in the screenshot before it you can see the x,y pre-measurements). For the gamma+color calibration itself you can see here http://www.avsforum.com/forum/attachment.php?attachmentid=2041841&d=1490159683 that there are no "-" markings which means the setup is good and it did not skip any steps during the gamma+color (I watched it).



Yes, for sure. In fact in the last screenshots you can see my dE after the custom color profile and there are all improved to under dE of 2 (compared to 4ish without the custom color profile).



As far as I know I am following the procedure to the letter. I even turned off motion enhance and clear black because you guys said to, even tho I never did this in the past.

I used all the proper starting presets so that nothing would be skipped. I then ran a gamma 33+color. Gamma droop checked and present afterward. Then switched from Standard to Rec709NF. Then ran a color only autocal. Gamma droop measures the same. Then created a custom color profile. dE's dropped considerably and measure great (as does the gamut and color checker all within dE of 0.5 or lower!) but the droop of course is still present. :mad:

To confirm, you can see my initial setup screen here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041857&d=1490159719

When it starts running, you can see that it is set to correct everything (not dashes) in this screen here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041841&d=1490159683

On the results graphs you can see it SAYS my gamma curve was fixed as shown by the straight line here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041865&d=1490159752

But in reality it is NOT fixed and I have considerable gamma droop, as shown when measured in CalMAN here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041897&d=1490159983 . This was manually correctable in just 15 minutes. But the bigger issues is not the extra 15 minutes but rather that the internal gamma is still off except for this manual curve, so all other curves like 2.4 or even custom imported curves will be affected by the droop.

You can see that the grayscale was not adjusted either, as seen here: http://www.avsforum.com/forum/attachment.php?attachmentid=2041881&d=1490159769 which compared to yours in post #2 mine is a very messy (yours was a much tighter D65 grouping). I posted specifically about this here: http://www.avsforum.com/forum/24-di...-x5000-rs400-rs500-rs600-55.html#post51683329

Have I missed anything?



In the past, I never had measured my results with CalMAN afterward. I was just blindly trusting that the autocal fixed the gamma droop because of the straight gamma line it would show afterward, while the "before" line would sometimes be bowed downward. Here it shows me a perfectly straight gamma vs reference gamma line, but CalMAN shows there is really a droop. Oh and BTW, yes, I am hitting Save after the autocal procedures. :)



No - just to confirm, NONE of this has anything to do with eeking out brightness. My intention was to do a fresh autocal and get a great, clean starting point. And THEN do crazy stuff with the gains and High Bright and experiment to see what I could get. However I never got that far, because these attempts at a clean, normal autocal as a baseline for such experiments had these issues. So I've only done the gamma+color and then color only autocals as would normally be done. I'm still in 6500K with no RGB gains/offsets, still at Gamma Normal, etc. Yes I have the droop.

The custom color profile nicely takes care of the color temp issues (although it is still a mystery as to why autocal is not making ANY changes to the grayscale even if it thinks they are right and actually wrong due to Spyder 5, but in my case its not even improving them as far as the Spyder 5 is concerned, as covered above). The big concern is the gamma droop.

I feel like I have dotted every i, and crossed every t. I've been through the procedure at least two dozen times in the past couple of days. Same results each time. What could I be missing? :confused: I feel like I've gone back to the basics as much as possible and tried from scratch over and over, yet nothing changes. What would you recommend I do as far as trying to find the issue? The most basic thing I can do is an autocal with gamma+color and then measure immediately after without touching ANYTHING, which I've done, and shows the same gamma droop.

Thank you!!
If it was working before and it's not working now, what has changed in your set-up if it's not the parameters?

- Are you using the same meter placement, as recommended in the procedure?
- Have you changed the bulb in the projector? A new bulb migh be instable for at least 50 hours or so.
- Are you warming up meters and projector for at least 45mn before running the autocal?
- Is the room not temp-controlled, so is the temperature in the room rising after the 45mn warm-up? If it does, it can skew the calibration results.
- Etc...

Don't focus too much on my result you've quoted for my 6500K results, that was a particularly good result, I haven't seen that in a long time. The various measurements are not always that close to D65 after the autocal. Autocal should, however, at least make an attempt to correct things. If you're using the standard/6500K presets and are following the procedure to the letter, then I have no idea what the explanation is apart from the above (wrong meter placement, new bulb yielding different results because it's still burning-in and rapidly changing, not enough warm-up time before running the autocal, non-constant temperature in a non-temp-controlled room, etc).

Good luck!
 

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If it was working before and it's not working now, what has changed in your set-up if it's not the parameters?
Well, the thing is, I never used CalMAN in the past (prior to these troublesome sessions) to measure the grayscale and gamma droop correction. I only used it to touch up 100%. I had just assumed it was fixing the gamma group based on seeing the straight line gamma in the first graph of the autocal results. So I cannot say whether it always had this droop. I just know with others posting their results I haven't seen the droop and even Arve said there must be something wrong with the autocal after seeing the droop with his BT1886 curve.

- Are you using the same meter placement, as recommended in the procedure?
Yes. Spyder 5 is about 8 feet or so from the lens and in the autocal it shows it within the box, about 15%-20% away from the "too bright" side of the box. This is the same exact placement I've always used. In fact at 16:9 zoom with iris 0 it is too bright, but when I zoom out it is not so that is how it is calibrated (zoomed for 2.40, which is all I'm interested in calibrating for at the moment).

I could try to locate this so it is closer to the dimmer side of the box (moving the meter closer to the screen) if that may help? For the i1D3 I have it facing the screen, about 12-18" away.

- Have you changed the bulb in the projector? A new bulb migh be instable for at least 50 hours or so.
No, I'm using the same original bulb. Now on about 750 hours. I've put 100 hours of almost all calibration time on the bulb in the past two weeks alone (between the custom curve work and this). :eek:

- Are you warming up meters and projector for at least 45mn before running the autocal?
Yes I always make sure the pj is running for at least 45 minutes before doing any calibration work.

- Is the room not temp-controlled, so is the temperature in the room rising after the 45mn warm-up? If it does, it can skew the calibration results.
- Etc...
Room has its own climate control system - same humidity, same temperature 72 degrees always +/- 1 degree. Meters are stored in the room and are room temp.

Don't focus too much on my result you've quoted for my 6500K results, that was a particularly good result, I haven't seen that in a long time. The various measurements are not always that close to D65 after the autocal. Autocal should, however, at least make an attempt to correct things.
Right. In looking at my pre and post log info from the autocal, do you agree that it is not really even attempting to correct anything? The pre and post xy are almost identical. I wonder what could cause that? I mean its one thing if it said they were closer to .313, .329 but when measured with another meter they weren't, but even the autocal is not changing them. The very small differences between pre and post log results seem to be related to just what it measures a second time (measuring variance in the Spyder) without it really changing anything. :confused:

If you're using the standard/6500K presets and are following the procedure to the letter, then I have no idea what the explanation is apart from the above (wrong meter placement, new bulb yielding different results because it's still burning-in and rapidly changing, not enough warm-up time before running the autocal, non-constant temperature in a non-temp-controlled room, etc).

Good luck!
Thanks. Yes you can verify with your own eyes in the start up screen I posted that it has the standard and 6500K preset and normal gamma. I can also rule out all else you mention. I'm happy to experiment more but I've just been going in circles and circles, as I don't know what else to try.

Question: When you look at the graph that shows my gamma droop, do you consider that statistically and real-world significant? Or is a droop to around 2.1 not going to be noticeable? The droop looks bad on the graph, but I notice that on the dE 2000 chart the dE for the upper range is still less than 2.0. IIRC, dE 2000 takes gamma into account right? So with a power gamma of 2.2, and my gamma droop at the worst at 95%, with dE 2000 of 1.5 at 95% doesn't that say that the result is still excellent and not noticeable to the eye? If so I don't want to be obsessing on a chart if it has no real-world PQ significance. If it does have a significance, however, then it needs my full attention like it currently has.

Most people are able to get an excellent gamut by following Chad's procedure.
Yes. If you forget about the droop, with the custom color profile and a fairly trusted meter (i1D3) I have dE 2000 of 1.5 or less across the full range and dE in the color checker of 0.5 or less. That's exceptional. My concern is just with the gamma drooop.

I'm not sure if the problem is with autocal. Your previous posts indicated that you were measuring both gamma spike and gamma droop, without re-running autocal. BTW, did you change the Super White setting?
Have you tried restoring the INIT calibration to see if gamma droop?
Yes I don't know what caused the spike readings. But since then I've started over a dozen times and I only get a droop. What super white setting, where? Mine is set to Auto. Should I forget HDMI type to Standard?

I haven't tried restoring the INIT calibration. Do you think that's worth it? Don't want to take a chance of messing things up?

Speaking of which, I wonder if a factor reset is in order? I certainly do not want to do that unless as a last resort.

Thanks!
 

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Discussion Starter · #1,639 · (Edited)
Yes. Spyder 5 is about 8 feet or so from the lens and in the autocal it shows it within the box, about 15%-20% away from the "too bright" side of the box. This is the same exact placement I've always used. In fact at 16:9 zoom with iris 0 it is too bright, but when I zoom out it is not so that is how it is calibrated (zoomed for 2.40, which is all I'm interested in calibrating for at the moment).

I could try to locate this so it is closer to the dimmer side of the box (moving the meter closer to the screen) if that may help? For the i1D3 I have it facing the screen, about 12-18" away.
Your meter position is wrong. You should set the meter so that, when set to the user mode/lamp mode/iris setting/zoom factor you're about to calibrate for, the meter is at the right edge of the box. This is especially important to measure non-zero values at low light levels during the gamma autocal. Some people report some issues doing this, in that case you need to back off, but that's what I and many others use with success. Also make sure that you are aiming the meter properly, ie the shadow of the measuring part of the meter should be in the center of the screen, and the reflection of the meter should be just below or just above the lens. All these is explained in detail in the first posts/links.

Question: When you look at the graph that shows my gamma droop, do you consider that statistically and real-world significant? Or is a droop to around 2.1 not going to be noticeable? The droop looks bad on the graph, but I notice that on the dE 2000 chart the dE for the upper range is still less than 2.0. IIRC, dE 2000 takes gamma into account right? So with a power gamma of 2.2, and my gamma droop at the worst at 95%, with dE 2000 of 1.5 at 95% doesn't that say that the result is still excellent and not noticeable to the eye? If so I don't want to be obsessing on a chart if it has no real-world PQ significance. If it does have a significance, however, then it needs my full attention like it currently has.
No, dE2000 doesn't take luminance into account, which makes it pointless for gamma calibration. You need to select dE2000JNDab in application measurement options, both for the dE formula and the dE Cube formula (if you use a 3D LUT Autocal at some point with MadVR, Radiance etc). Your dE at 95% is likely above 2 when taking luminance into consideration. Your gamma droop is abnormal, especially after an autocal, but it's not massive. It probably leads to a slight loss of dimensionality, but it shouldn't be drastic. I wouldn't lose my sleep about this, because even if you get it right either with the autocal or manually, it will look like this again in 50 hours or so, possibly even earlier.

Yes I don't know what caused the spike readings. But since then I've started over a dozen times and I only get a droop. What super white setting, where? Mine is set to Auto. Should I forget HDMI type to Standard?
If you resolve the correct levels with brightness and contrast at zero, then auto is doing its job. You can select standard to be sure, but then check your levels again, the source needs to be set to standard too for the measurements to be correct.


I haven't tried restoring the INIT calibration. Do you think that's worth it? Don't want to take a chance of messing things up?

Speaking of which, I wonder if a factor reset is in order? I certainly do not want to do that unless as a last resort.

Thanks!
Don't waste your time doing a full reset or restoring the init backup, it's very unlikely to solve this issue.
 

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Most people are able to get an excellent gamut by following Chad's procedure.
I know...but, unless there is a way to make sure what autocal reports is true, there should always be a doubt about the excellent gamut the autocal software reports. In my case, deltaE for color saturation (to a lesser extent) and intensity (to a greater extent) show visibly worse results after autocal, as verified with Chromapure3 and EyeOne Pro off the screen (before vs after color autocal). There must be something I am doing wrong, I know, but if I only trust the post autocal report, everything seems better...which is not the case, visually and mathematically.

Hopefully, I will find the problem. I have read, reread this whole thread a few times, I have tried a new lamp, a new Spyder5, no change. My color gamut (freshly imported REC709NF file) looks bad OOTB, and it looks worse after autocal...:( I am believing more and more that my RS500 itself is the problem.
 
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