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Radiance 3D LUT (5x5x5 Cube) Calibration with CalMAN 5 - Page 16

post #451 of 747
Quote:
Originally Posted by fragfeaster777 View Post

Hi,
Sorry for the delayed response, has been a crazy week.
Anyway, I decided to try to recalibrate using YCrCb 4:2:2 and see what happened. I again made sure that there's no clipping at 100% white, that 30% and 100% RGB was balanced, and that colour temperature was 6500k. I did not mess with the projector's CMS.
Again, the results were unwatchable: I've attached 3 pics I took with my phone from the S&M demonstration material.
Tomorrow, I will try fiddling with the projector's CMS prior to calibration to see if this can be fixed. In the meantime, any suggestions would be appreciated.
Thanks!
20121117_013026(0)_resized.jpg 371k .jpg file 20121117_013241_resized.jpg 527k .jpg file 20121117_013313_resized.jpg 431k .jpg file

Well here's what happened with me. I'm not sure this will be any help because I have a different display (JVC RS20). But I had the same results. To get the 30%, 100% settings as close as possible I had used the bias control (offset?) to get red up so I wouldn't loose brightness. I found the results unwatchable much as you describe, with too much red in low light scenes and a lot of banding. Then I noticed my CR was only about 750:1 or so. In trouble-shooting that, I determined that bringing the red bias above 0 had killed my CR. I could see the background darken up as I took the bias out. So then I ran it again. My CR measured at 24k:1, good for full open iris and long throw (20'). More importantly, the auto-cal results are now spectacular... like looking through a window. The fact there's a screen there completely disappears and the image completely takes over reality.

BTW: We watched Lawrence of Arabia last night. Holy Moly is all I can say.
post #452 of 747
Quote:
Originally Posted by erkq View Post

Well here's what happened with me. I'm not sure this will be any help because I have a different display (JVC RS20). But I had the same results. To get the 30%, 100% settings as close as possible I had used the bias control (offset?) to get red up so I wouldn't loose brightness. I found the results unwatchable much as you describe, with too much red in low light scenes and a lot of banding. Then I noticed my CR was only about 750:1 or so. In trouble-shooting that, I determined that bringing the red bias above 0 had killed my CR. I could see the background darken up as I took the bias out. So then I ran it again. My CR measured at 24k:1, good for full open iris and long throw (20'). More importantly, the auto-cal results are now spectacular... like looking through a window. The fact there's a screen there completely disappears and the image completely takes over reality.
BTW: We watched Lawrence of Arabia last night. Holy Moly is all I can say.

Yes glad you figured it out. As I was reading your post I was thinking "oh no no no, he didnt't" smile.gif. Glad you figured it out. Raising any of the bias controls on the rs20 will destroy the CR and PQ. Lowering then is ok. This has been covered in great detail years ago if you want more info.
post #453 of 747
Quote:
Originally Posted by lovingdvd View Post

Yes glad you figured it out. As I was reading your post I was thinking "oh no no no, he didnt't" smile.gif. Glad you figured it out. Raising any of the bias controls on the rs20 will destroy the CR and PQ. Lowering then is ok. This has been covered in great detail years ago if you want more info.

Oh, yes... yes "he" did! Funny they'd give you a control, 1/2 of whose range would completely "f" things up! Yup... I checked out of the forums "years ago" because I was watching movies! Now I'm back to look at projectors 3? 4? generations newer and amazing, affordable calibration tools. Times are good.
post #454 of 747
Quote:
Originally Posted by fragfeaster777 View Post

Again, the results were unwatchable: I've attached 3 pics I took with my phone from the S&M demonstration material.
Tomorrow, I will try fiddling with the projector's CMS prior to calibration to see if this can be fixed. In the meantime, any suggestions would be appreciated.]

After taking a look at the pre/post stuff a little more closely it looks like something is definitely going wrong.

We've seen issues where large amount of correction can cause the type of issue you're seeing in the lumagen. But even then you should see better colorchecker measurements in the post than you do in the pre-measurements.

Without more information it's hard to know what is happening.

Try turning on the logging information for AutoCal (Main Menu->Logging...).

When you've run it, grab the log file and *.cdfx file and post them and we'll have a much better idea as to what is going on.

(C:\ProgramData\SpectraCal\CalMAN 5 Home Theater\Logs)
(C:\Users\USER_NAME\Documents\SpectraCal\CalMAN 5 Home Theater\CDFs)
post #455 of 747
Posting this message slightly differently as the 'powers that be' didn't like the previous post...

As a Radiance user, I have to post to say the problem is not with the Lumagen box.

All the calibrations we have done with the box work exactly as expected, and even starting with 'incorrect' pre-calibration settings doesn't result in an image that is unwatchable. All calibration should understands what can, and what can't be calibrated, and do the best it can to calibrate what can be calibrated, and shouldn't allow what can't be calibrated to adversely affect the final result.

But, it is also true that getting the pre-calibration correct will result in better final calibration.

As always, happy to answer any questions.

Steve
post #456 of 747
Quote:
Originally Posted by Light Illusion View Post

Posting this message slightly differently as the 'powers that be' didn't like the previous post...
As a Radiance user, I have to post to say the problem is not with the Lumagen box.
All the calibrations we have done with the box work exactly as expected, and even starting with 'incorrect' pre-calibration settings doesn't result in an image that is unwatchable. All calibration should understands what can, and what can't be calibrated, and do the best it can to calibrate what can be calibrated, and shouldn't allow what can't be calibrated to adversely affect the final result.
But, it is also true that getting the pre-calibration correct will result in better final calibration.
As always, happy to answer any questions.
Steve

Since only one 3D LUT Cube calibration is needed / necessary / recommended, yet getting it 'somewhere near' benefits the process surely a second Autocal would help the processing if the first one fails?

Do you mean that sometimes for example a faulty Display will adversely affect the Autocal result?

My Panel's inability to reach correct maximum rec709 values for its Blue element would be in the 'understand what what can and what cannot be calibrated' category..
post #457 of 747
A good pre-calibration is not the same as 'getting it near'.
It means making sure the extremes are within the display's range - not clipping, etc.
Checking the black and white levels before calibration for example.

And no, if a cube calibration fails, a second cube calibration will not fix it.

I can't comment on the 'autocal' approach as we separate profiling from calibration.
This makes the whole calibration process a lot simpler, and more accurate.

All I was saying is that the problem is not with the Radiance box.
It has more to do with the workflow being used, and that may be dictated by the software.

But, having a low blue gamut should not affect the rest of the display calibration,
Again, if it does, the workflow is at fault.

Steve
post #458 of 747
Thanks for the replies guys

Joel, I performed another calibration yesterday before getting your message on the logging, but I will clear the settings, switch on the logging, rerun the process and then post the files for you.

I did a full pre-autocal this time before, including messing with the CMS. Here are the results:

* Gamma DeltaL Max: 3.4
* Gamma DeltaL Avg: 1
* ColorChecker de2000 Max: 6 (In the LUT workflow)
* ColorChecker de2000 Avg: 2.9 (In the LUT workflow)
* In the Enthusiast workflow, in the CMS page, I got all the primaries and secondaries to be under Delta 3
* Colour temp: 6504
* Contrast: 553
* Light output: 24fl

So results pre-calibration were actually pretty good.

After running the autocal process, here are the results:

* Gamma DeltaL Max: 2.8
* Gamma DeltaL Avg: 0.6
* ColorChecker de2000 Max: 2.9
* ColorChecker de2000 Avg: 1.7
* Colour temp: 6336
* Contrast: 318
* Light output: 14fl

This time, there was absolutely no evidence of any banding or other artifacts, and colours were spot on, great! However, light output fell from 24fl to 14fl, contrast was pretty bad, and the colour temperature was slightly off. A visual inspection of the results showed that the image was just bland due to the lack of contrast and light, and the pre-autocal results looked much better

I will try again with the logging enabled to see if it may help find a solution.

Thank you all!
post #459 of 747
Quote:
Originally Posted by sotti View Post


Try turning on the logging information for AutoCal (Main Menu->Logging...).
When you've run it, grab the log file and *.cdfx file and post them and we'll have a much better idea as to what is going on.
(C:\ProgramData\SpectraCal\CalMAN 5 Home Theater\Logs)
(C:\Users\USER_NAME\Documents\SpectraCal\CalMAN 5 Home Theater\CDFs)

After using 5.04 RC1, it looks like you guys are headed in the right direction. My question is how long before you have a in sync version of 5.04 with its sync feature for the C6 using a VT50 working well ???

Also if I do a clean install of a later version of calman will it save my meter profiles, if not how can I save the meter profiles and transfer them to the newly installed version of calman?

ss

It seems that if you delete the old version of Calman and install a new version it will save your meter profiles.
Edited by sillysally - 11/20/12 at 7:15am
post #460 of 747
Joel,

I've attached below the 2 files, hopefully they can give some insight. The autocal was done after I dialled in the CMS and gamma manually, ie the settings where I see a drop in light output from 24fl to 14fl. Thanks!

19112012 BenqW7000 postCMS_1.zip 3181k .zip file
log.zip 49k .zip file
post #461 of 747
Just wanted to give you guys an update: After much frustration of trying to figure out why my calibration numbers were somewhat different each time I tried to get some readings, I by mistake realised that the Benq does not treat 60p and 24p the same. What was happening is that I had the S&M disc in the background, but when not playing, the Panasonic bluray player would output 60p, and so would the Radiance, but today I by mistake left the disc playing, realised that the Lumagen was outputting 24p and my manual calibration numbers were significantly different.

Therefore, I will try an autocal session this weekend with the disc playing at 24p to see if this was the cause of my previous bad results.

Also, would anyone know how to completely clear any settings from the Radiance? I tried using the Reset Factory Default option and then saving (as per the Lumagen manual), but I notice that under the CMS option, the gamma points stays at 11, even though I know the default is 2.

Thanks
post #462 of 747
Quote:
Originally Posted by fragfeaster777 View Post

I tried using the Reset Factory Default option and then saving (as per the Lumagen manual), but I notice that under the CMS option, the gamma points stays at 11, even though I know the default is 2.

I believe 11 is the default with the current firmwares.
post #463 of 747
Ah ok thanks, it was just because CMS1-8 had the gamma points at 2, whilst the CMS 0 memory (which I was using for autocal) had the setting at 11, even after the reset, so I thought it hadnt cleared my autocal settings.

Did you guys manage to extract anything interesting from the log files?
post #464 of 747
Quote:
Originally Posted by fragfeaster777 View Post

Ah ok thanks, it was just because CMS1-8 had the gamma points at 2, whilst the CMS 0 memory (which I was using for autocal) had the setting at 11, even after the reset, so I thought it hadnt cleared my autocal settings.
Did you guys manage to extract anything interesting from the log files?

For some reason I can't extract the CDFX file from the zip.

I haven't seen anything strange in the LOG file off hand, but It'd know more if I could get the CDFX file as well.
post #465 of 747
Quote:
Originally Posted by sotti View Post

For some reason I can't extract the CDFX file from the zip.
I haven't seen anything strange in the LOG file off hand, but It'd know more if I could get the CDFX file as well.

Ah sorry, it's cause it was 11 megs and the forum only accepts 5 megs, so I used 7zip to compress it. Shall I email it to you instead? If so, if you could send me your email, that would be great. Thanks!
post #466 of 747
Re-calibrated my JVC RS55 the other day. I'm getting the best results starting with the color profile Standard and the 6500K color temp default and not adjusting the gain/offsets and letting the Lumagen do the rest. The graphs always come out pretty good no matter what I use, but the picture/color just looks better to me. SJ
post #467 of 747
Quote:
Originally Posted by SJHT View Post

Re-calibrated my JVC RS55 the other day. I'm getting the best results starting with the color profile Standard and the 6500K color temp default and not adjusting the gain/offsets and letting the Lumagen do the rest. The graphs always come out pretty good no matter what I use, but the picture/color just looks better to me. SJ

Hi SJHT,

If you have the results at hand, could you maybe help me by posting how your pre and post calibration gamma and CMS screens look like. If you could also post what contrast ratio you are getting, what light output you got pre and post, and verify that there's no clipping at 100W pre calibration, that would also be great. Basically I may try to get the precalibration settings to be close to your values, and then see if the Radiance does a better job at correcting, as opposed to what I'm doing of getting the pre-calibration as close as possible cause that's not working out for me.

Thank you very much!
post #468 of 747
Sorry, but don't have it. SJ
post #469 of 747
Well I finally have some good news to report!

I was tweaking the projector's gamma manually to try to get is as tight as possible to 2.2, and got gamma DeltaMax to 1.5 and DeltaAvg to 0.6. I then thought to check what would happen if I skipped the gamma autocal step, because I was pretty happy with the manual result. That did the trick and produced none of the errors that I previously encountered. I now have ColorChecker Max at 3, Cube Max at 6 and Cube Avg at 1. Gamma remains as it was. Importantly, there was no loss of light and I'm still getting 24fl, with a contrast of 560 (the same as pre-calibration)

I briefly threw some 2D material at the W7000 and the results looked very good indeed. I will be doing some proper viewing over the next few days and will report back.

Thanks to all that have tried to help me with this issue, I appreciate everyone's valuable input and hope my experience can help some of you too.
post #470 of 747
Quote:
Originally Posted by fragfeaster777 View Post

Well I finally have some good news to report!
I was tweaking the projector's gamma manually to try to get is as tight as possible to 2.2, and got gamma DeltaMax to 1.5 and DeltaAvg to 0.6. I then thought to check what would happen if I skipped the gamma autocal step, because I was pretty happy with the manual result. That did the trick and produced none of the errors that I previously encountered. I now have ColorChecker Max at 3, Cube Max at 6 and Cube Avg at 1. Gamma remains as it was. Importantly, there was no loss of light and I'm still getting 24fl, with a contrast of 560 (the same as pre-calibration)
I briefly threw some 2D material at the W7000 and the results looked very good indeed. I will be doing some proper viewing over the next few days and will report back.
Thanks to all that have tried to help me with this issue, I appreciate everyone's valuable input and hope my experience can help some of you too.

Is this the BenQ W7000? If so, why are you getting such low contrast numbers? It's rated at 50,000 the same as my JVC RS20 and I get 24,000:1 with the iris full open. I realize CR specs are all over the place and change even further from that with iris settings and throw distances. But 560:1 is almost a full 2 orders of magnitude from what I'm getting with a similarly spec'd projector.

Maybe I just haven't been following the conversation attentively enough. Maybe your W7000 is not the BenQ at all...
post #471 of 747
Quote:
Originally Posted by erkq View Post

Is this the BenQ W7000? If so, why are you getting such low contrast numbers? It's rated at 50,000 the same as my JVC RS20 and I get 24,000:1 with the iris full open. I realize CR specs are all over the place and change even further from that with iris settings and throw distances. But 560:1 is almost a full 2 orders of magnitude from what I'm getting with a similarly spec'd projector.
Maybe I just haven't been following the conversation attentively enough. Maybe your W7000 is not the BenQ at all...

Yep, its the Benq W7000. I'm not too surprised by the results, for example, if you look at Chris' review http://www.hometheaterhifi.com/projectors/projectors-reviews/benq-w7000-projector/page-4-on-the-bench.html, after calibration he is getting 29fl on his 1.3 gain screen and I'm getting around 24-25fl on my 1.0 screen, whilst our black levels are about the same (0.03fl). So he's getting a contrast of 890 and I'm getting around 560, by virtue of his higher gain screen.

If I were to switch on dynamic iris, then I'm getting a 2000:1 contrast ratio reading, but the projector wouldn't be calibrated that way. Also one could get much higher contrast with increased light output, but then red starts to clip after around 25fl in economic mode, so the picture wont be calibrated. I'm sure Benq did it's numbers when cranking up light output to the max and then switching on dynamic iris

I did ask in the W7000 forum what contrast ratio's were people getting from their calibrated machines but no-one replied.

I don't know much about the JVCs, but from what I've read is that your blacks are much, much deeper.
post #472 of 747
Thanks for responding! Makes sense. Real-world numbers can be so different from marketing numbers.
post #473 of 747
Quote:
Originally Posted by fragfeaster777 View Post


If I were to switch on dynamic iris, then I'm getting a 2000:1 contrast ratio reading, but the projector wouldn't be calibrated that way.

Yes, your projector WOULD be correctly calibrated with the dynamic iris being used... many people do not understand this point... only your MEASUREMENTS would not look right when the dynamic iris is turned on. The IMAGES would be perfectly calibrated if you turn the dynamic iris off for calibration then turn the dynamic iris back on for viewing. Here is why...

Think of the dynamic iris as having just 3 settings... open, closed, and half-open. Let's say you select the half-open setting to use for calibration. You set gamma to 2.2 and get grayscale adjusted so that there are low errors and CMS also has low errors. Now... manually switch to open iris mode and make measurements again... gamma will still be very close to 2.2 because ALL STEPS are brighter with the same proportions. Grayscale will remain properly balanced. CMS will remain properly balanced. Now, manually switch to closed iris position. Make the measurements again... gamma will still be very close to 2.2 because all steps are darker in the same proportion. Grayscale will still be calibrated (just darker) and CMS will still be calibrated (but darker).

Auto Iris is like using manyal iris settings, but the projector decides when to open or close the iris based on how bright or dark the images are. This does NOT "de-calibrate" images... it simply changes the overall luminance, but it does that over the entire screen, not selectively. This is why auto-dimming LCD and auto-iris for projectors are GOOD things... because they do NOT mess with your calibration in any way that will detract from image accuracy or quality. I always use auto-dimming or auto-iris after calibrating as long as there is not some problem caused by doing that... some auto-iris mechanisms are VERY NOISY (Epson comes to mind) and I find that very distracting. Some auto-iris functions produce obvious and distracting luminance changes at times the iris should not be moving. Sony has done a great job of creating auto-iris algorithms that work invislbly... some other brands are also quite good. A few other brands need to figure out what they are doing wrong that other brands are doing right. But aside from too much noise or too-obvious iris changes, I would always choose to use auto-iris if it is well-implemented over using a fixed iris opening.
post #474 of 747
Quote:
Originally Posted by Doug Blackburn View Post

...
Now... manually switch to open iris mode and make measurements again... gamma will still be very close to 2.2 because ALL STEPS are brighter with the same proportions.
...

I'll have to really read and analyse what you're saying more. It is interesting. But, on the face of it, you are saying something here that is simply not true. It is very well known that opening/closing the iris effects contrast ration in a major way. And contrast ratio is the measurement of the brightness of one step to the next. So this proportion is changed if the projector's iris is changed. My projector's cr virtually doubles between full open and full closed. Am I missing something?

EDIT: Oh... wait... I think I'm "getting" it.
Edited by erkq - 11/25/12 at 3:15pm
post #475 of 747
Quote:
Originally Posted by Doug Blackburn View Post

Yes, your projector WOULD be correctly calibrated with the dynamic iris being used... many people do not understand this point... only your MEASUREMENTS would not look right when the dynamic iris is turned on. The IMAGES would be perfectly calibrated if you turn the dynamic iris off for calibration then turn the dynamic iris back on for viewing. Here is why...
Think of the dynamic iris as having just 3 settings... open, closed, and half-open. Let's say you select the half-open setting to use for calibration. You set gamma to 2.2 and get grayscale adjusted so that there are low errors and CMS also has low errors. Now... manually switch to open iris mode and make measurements again... gamma will still be very close to 2.2 because ALL STEPS are brighter with the same proportions. Grayscale will remain properly balanced. CMS will remain properly balanced. Now, manually switch to closed iris position. Make the measurements again... gamma will still be very close to 2.2 because all steps are darker in the same proportion. Grayscale will still be calibrated (just darker) and CMS will still be calibrated (but darker).
Auto Iris is like using manyal iris settings, but the projector decides when to open or close the iris based on how bright or dark the images are. This does NOT "de-calibrate" images... it simply changes the overall luminance, but it does that over the entire screen, not selectively. This is why auto-dimming LCD and auto-iris for projectors are GOOD things... because they do NOT mess with your calibration in any way that will detract from image accuracy or quality. I always use auto-dimming or auto-iris after calibrating as long as there is not some problem caused by doing that... some auto-iris mechanisms are VERY NOISY (Epson comes to mind) and I find that very distracting. Some auto-iris functions produce obvious and distracting luminance changes at times the iris should not be moving. Sony has done a great job of creating auto-iris algorithms that work invislbly... some other brands are also quite good. A few other brands need to figure out what they are doing wrong that other brands are doing right. But aside from too much noise or too-obvious iris changes, I would always choose to use auto-iris if it is well-implemented over using a fixed iris opening.

Hi Doug,

This is interesting, but why would greyscale not be affected with a dynamic iris, when it is in my experience significantly affected with a static iris?

On all the JVCs I've calibrated, changing the iris setting has a HUGE effect on greyscale, and a significant effect on gamma as well as the effect on greyscale is not linear over all the colors at all the steps, so you lose more luminance at some steps than some others, which disrupts your nice flat gamma curve.

Try to calibrate to D65 and 2.2 gamma any JVC projector with the iris fully closed, and then open the iris fully and remeasure. If you get something that is still correct, I'd be very surprised.

You have to select your iris setting before calibrating gamma/greyscale on the JVCs (taking into account any drop of brightness due to white point/gamut calibration), otherwise you end up with a poor calibration.

This is also why it is necessary to recalibrate often (at least every 200 hours for the JVCs in my opinion, I personally do it more often than that) as the lamp dims. Opening the iris as the bulb ages allows you to compensate for the loss in brightness (at the cost of on/off contrast), but it introduces significant variations in greyscale/gamma (not that much on gamut). Not unwatchable, but far enough from the standard to be visible to a trained eye.

So are you saying that this isn't the case with a dynamic iris?

I have no experience with a dynamic iris, so this is a genuine question:).
Edited by Manni01 - 11/26/12 at 4:17am
post #476 of 747
I have to say that using Dynamic Iris will make any calibration incorrect...

The reason is exactly the same as with Plasma ABL.
As the overall scene brightness changes, the Dynamic/Auto Iris will try to compensate.
This is not the same as running calibration with the Iris set to Closed. Half Open, and Open - as they are fixed settings.

With auto iris the readings with a profile sweep will change dynamically as the patch brightness changes, so distorting the calibration data.
So, this means when playing back a 'film' with dynamic iris on the visual result will be very different to the film producer's original intent.

Does this make sense?

Steve
post #477 of 747
And yet, when looking at a high APL movie scene turning auto iris on and off makes absolutely no visual difference relative to a fixed iris setting with a comparable light output; and most of the time low APL scenes look significantly better with auto iris vs. fixed.

Despite the decrease in stability and possible white balance shifts at the dark end auto iris can cause, the large increase in CR can be visually more important. The difference in gamma is more due to the measurements tricking the auto iris and is, for the most part, not real; in other words, the gamma may be just fine with normal content despite terrible looking measurements.

Auto iris works by electronically and dynamically boosting low levels to compensate for closing the iris in low APL scenes. This electronic boosting for a mechanical difference procedure is not perfect, but it yields high returns in contrast ratio. Whether it's worth it or not will depend on your personal preferences, and if you tend to obsess over certain things more than others.
post #478 of 747
This can also depend on each plasma display's ABL (also LED local dimming algorithm) / projector's auto iris implementations.. one of the fp sent to me absolutely destroyed the calibration with it's auto iris.
post #479 of 747
What kind of patterns do the Lumagen processors generate to do the cube calibration? Field, window, APL small window, APL large window?
post #480 of 747
Quote:
Originally Posted by JimP View Post

What kind of patterns do the Lumagen processors generate to do the cube calibration? Field, window, APL small window, APL large window?

Same as before 5x5x5. Full screen, a 10-11% window and a very small window. If I remember correctly the smallest window height is about 2x the diameter of a Chroma 5. I used the 10-11% window when I had a Panny plasma.
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