Official JVC RS20 / HD750 Calibration and CMS thread (NEW FIRMWARE V1.1) - Page 33 - AVS Forum
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post #961 of 1634 Old 07-31-2009, 08:06 AM
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No nifty graphs, but I calibrated the color on my RS-20 yesterday using my Progressive Labs CA-6x probe and a light meter. I took the results directly from the projector using a difuser and a calculated offset for the screen. I find that I am able to get much more repeatble results at low IREs doing this. I calibrated to SMPTE-C (601) for all the reasons that gregr has previously noted.

As folks have noted, the THX mode is under-saturated, although the hue is relatively accurate. This is actually pretty good for a factory mode. The color controls were very easy to use and very linear. My only advice is to note that the light meter is of course very sensitive to distance from the projector, and really has to be tri-pod mounted for repeatable results.

I wish I could say that the gamma controls were easy to use as well! When you adjust one point up or down, it automatically adjusts adjacent points. I couldn't figure out the logic behind the adjacent point adjustments -- my best guess is that the control represents some kind of parabolic curve, and the projector is providing a negative input to adjacent points to dial out the 'wings' of the parabola -- but doing it wrong. I speculate, however. And then of course, it has an amazingly clunky copy and save interface. It took me a couple of hours to really get the hang of the gamma controls.

The net result is... spectacular. I haven't seen color this good since I was using an old Sony reference direct view video CRT at work. It is rich and vibrant, but flesh tones and natural colors still look utterly natural.

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post #962 of 1634 Old 07-31-2009, 09:03 AM
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[quote=Thebes;16900238]Hi,

a review from Secret of Home Theater about the Anthem LTX 500, (which is IMHO a RS20 Twin).

http://www.hometheaterhifi.com/proje...er-part-1.html

Thanks for the link.

Anyone else find reviews of re-badged projectors slightly annoying? Especially when there's no mention that the projector is essentially the JVC projector?
I wonder if there is some agreement between reviewer and re-badging manufacturers not to mention - "Pssst...this is a JVC projector." I dunno, it's just
vaguely unsettling to see any props sent Anthem's way for providing a "new reference projector" simply for sticking their name on the results of JVC's research and engineering.

Anyway, a quote from the end of the review:

"The Anthem LTX-500 is the best projector I have tested to date. If I were to write a marketing tagline for it, it would be, “Simply Accurate Color.” So few displays are this accurate and that made it all the more pleasurable to watch."

Boy how things have changed for JVC's rep since they decided to release a projector with accurate color huh?
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post #963 of 1634 Old 07-31-2009, 09:20 AM
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[quote=R Harkness;16919862]
Quote:
Originally Posted by Thebes View Post

Hi,

a review from Secret of Home Theater about the Anthem LTX 500, (which is IMHO a RS20 Twin).

http://www.hometheaterhifi.com/proje...er-part-1.html

Thanks for the link.

Anyone else find reviews of re-badged projectors slightly annoying? Especially when there's no mention that the projector is essentially the JVC projector?
I wonder if there is some agreement between reviewer and re-badging manufacturers not to mention - "Pssst...this is a JVC projector." I dunno, it's just
vaguely unsettling to see any props sent Anthem's way for providing a "new reference projector" simply for sticking their name on the results of JVC's research and engineering.

Anyway, a quote from the end of the review:

"The Anthem LTX-500 is the best projector I have tested to date. If I were to write a marketing tagline for it, it would be, Simply Accurate Color. So few displays are this accurate and that made it all the more pleasurable to watch."

Boy how things have changed for JVC's rep since they decided to release a projector with accurate color huh?

Its all about money. I wonder if he has to send the equiptment back or does he get to keep it?
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post #964 of 1634 Old 07-31-2009, 05:44 PM
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I own the LTX500 and I know from day one that its just a rebadged HD750. The difference is in the distribution and customer support. I own Anthem products and very pleased with their customer support. I don't know about JVC but with Anthem, there is really a person on the other side to take on the problem.

With the review, I would agree 100% with the findings. this is the best PJ I have owned since my Barco CRT days. I use the Progressive labs Ca-6x with the Xrite Hubble and a Sencore Vp403 to dial it in.
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post #965 of 1634 Old 08-02-2009, 03:53 PM
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Quote:
Originally Posted by abc999 View Post

I own the LTX500 and I know from day one that its just a rebadged HD750. The difference is in the distribution and customer support. I own Anthem products and very pleased with their customer support. I don't know about JVC but with Anthem, there is really a person on the other side to take on the problem.

With the review, I would agree 100% with the findings. this is the best PJ I have owned since my Barco CRT days. I use the Progressive labs Ca-6x with the Xrite Hubble and a Sencore Vp403 to dial it in.

I am curious as to how much a premium Anthem has tagged on?
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post #966 of 1634 Old 08-17-2009, 05:27 PM
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I am very happy to be a latecomer to this party as i have been able to benefit from the fixed CMS and all of your wonderful posts.

I have a new RS20 from Jason and it is delivering an amazing picture, a bigger jump from my RS2 than I was expecting, maybe bigger than the jump from my RS1 to RS2 once the CMS is tweaked.

I have two issues I wanted to run by you all. (I am using an i1pro in a batcave on a 120" wide 2.35 CIH setup on 1.3 gain.) First, I was surprised that the factor gamma curves were very different than what's reported here. For example, 2.2 measures from 2.0 (at 30%) to 1.7 (at 100%). I am surprised both by how low it is and how much it falls off. I got the same results facing the pj and also using my light meter and calculating by hand. So I don't think it's the meter or the software. To get a good gamma at 2.2 I had to start with 2.5 and tweak quite a bit.

The other thing, more troubling, is the amount of quantization apparent with the CMS engaged. I guess some of this is inevitable with matrix multiplies unless you go to 12 or 14 bits. But I thought 10 bits would do better. E.g., in Watchmen, there are some dark scenes with cyan and magenta adjacent where there is very dramatic solarization apparent at the border between the hues. My CMS numbers are not radically different that those posted here. Again, this is only under fairly extreme image conditions, but still...
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post #967 of 1634 Old 08-17-2009, 05:55 PM
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Quote:
Originally Posted by tomhahn View Post

...To get a good gamma at 2.2 I had to start with 2.5 and tweak quite a bit...

I did one and started with 2.6 to achieve 2.2 with minimal adjustment. Further working with the JVC Custom Gamma, I realized one can dial in 2.2 to actually do 2.2 it could take some time from scratch (or record the other 2.5,2.6 WRGB, 5,10,15,....,90,95 values and start there in 2.2) Just expect to spend "A LOT" of time. Results can be a very flat grayscale and accurate gamma curve.

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post #968 of 1634 Old 08-17-2009, 09:09 PM
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Quote:
Originally Posted by GlenC View Post

I did one and started with 2.6 to achieve 2.2 with minimal adjustment. Further working with the JVC Custom Gamma, I realized one can dial in 2.2 to actually do 2.2 it could take some time from scratch (or record the other 2.5,2.6 WRGB, 5,10,15,....,90,95 values and start there in 2.2) Just expect to spend "A LOT" of time. Results can be a very flat grayscale and accurate gamma curve.

Yep. If I remember right I started with 2.5 preset. I spent a good 6 solid hours calibrating WRGB to achieve a nearly perfect 2.2 across the entire range. Except it fell off a bit at 95 and 100% and nothing I could do about it without harming 90% too much.

What makes it so tricky is that the controls interact with each other from different levels. So you adjust one % level and it changes another.♠

The trick is #1 to first do the RGB tweaks without W to get as flat as possible for your grayscale calibration. Only then go back and do W for gamma.

Trick #2 is calibrate one step higher. For instance use the controls at 10% to adjust 5% while measuring at 5%. Then when that is good use the controls at 15% to adjust 10% while measuring 10%, and so forth. This way it at least will not change your "good" settings as you move along. And do not go back and forth! Start at 10% and go up to the top, but don't work backward unless you prepared to redo a lot.

I'm curious to hear if others have used this technique while dialing in a custom gamma.

And tomhahn congrats on your fine purchase and welcome to the club!
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post #969 of 1634 Old 08-17-2009, 10:00 PM
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Quote:
Originally Posted by lovingdvd View Post

I'm curious to hear if others have used this technique while dialing in a custom gamma.

The RS20 was more interactive among points than the RS2. With the RS2, I found little correlation to input signal % and the gamma adjustment point. After spending 20+ hours on a JVC Repaired RS2, I found a trick that generated fantastic results in a much shorter time. I do like to maintain some degree of maintaining a "value of service" for my customers. Yea, I know if I reveal all my secrets, you guy's won't tell anyone and there is no way I could loose valuable customers........ too risky, I just got my new Hip last Tuesday and really maxed out some CC's, it will take over 60 RS2/RS20 calibrations to recover my costs.....

I hope most of you understand my policy, with Professional Calibration services being my only source of income (as well as for others), as a professional courtesy, I refrain from disclosing steps or techniques that could have any potential of taking work away from myself or other calibrators.

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post #970 of 1634 Old 08-18-2009, 12:27 PM
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Quote:
Originally Posted by lovingdvd View Post

...
I'm curious to hear if others have used this technique while dialing in a custom gamma.
...

Hi Ric,

I wrote very detailed explainations and procedure here

I also designed a spreadsheet which produces fast and very efficient results.

If any difficulty, I will translate the key points
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post #971 of 1634 Old 08-18-2009, 12:59 PM
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GlenC:
Why did you need a new hip? (skiing accident?)
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post #972 of 1634 Old 08-18-2009, 04:02 PM
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Quote:
Originally Posted by John Ballentine View Post

GlenC:
Why did you need a new hip? (skiing accident?)

Old and worn out, accelerated by an accident.... It started with a bit of arthritis generating occasional pain while walking (2004)...... Nov '05, just after finishing the week of ISF training (assisting Joel), all the staff were going to dinner..... in the hotel parking lot, walking to my car, I got hit in the right hip..... airborne 15' (so I am told, horizontal, not vertical), I was left with a broken ankle, sore back and whiplash, among other hidden injuries. MRI for lawsuit in '08 reveled avascular necrosis of that hip (loss of blood flow to head/ball). Expected to be result of the accident, requiring future hip replacement....... Well after suffering for years with hip and low back pain, '09 was even worse, deterioration was accelerating........ With the need for relief, research got me to the #1 surgeon in the country. I am so anxious to be pain free in the hip that I am disappointed in my recovery progress. Surgery was Tues 8/11 and now, one week later, I haven't weaned myself from a walker My recovery would probably have been significantly reduced if I did this in 2006. My body and mind have been in a protective mode from pain for so long that it is a chore to retrain the mind that the current pain (not much) is good pain, not potential injury........

One thing I have learned, advice I can give..... If ones condition is such that a hip replacement will be needed, it is better to do it sooner than later. The surgeon and method used is probably the single most significant issue towards post surgery recovery and quality of life. While all are approved, the results for the patient cab have a range from fantastic 100% to disastrous, resulting in severe life long limitations on movement and activity levels.

I hope this was the appropriate answer, if not, the simple answer was severe Osteoarthritis with bone to bone contact.....

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post #973 of 1634 Old 08-18-2009, 08:11 PM
 
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Quote:
Originally Posted by GlenC View Post

I hope this was the appropriate answer, if not, the simple answer was severe Osteoarthritis with bone to bone contact.....

No criticism here....
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post #974 of 1634 Old 08-19-2009, 07:21 AM
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^^
Wow. Bummer. Hope you feel better soon! (and hope the lawsuit is covering your expenses.)
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post #975 of 1634 Old 08-19-2009, 07:48 AM
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Quote:
Originally Posted by John Ballentine View Post

^^
Wow. Bummer. Hope you feel better soon! (and hope the lawsuit is covering your expenses.)

Thanks, Attorneys are the only real victors in lawsuits. My attorney did manage to get things to a level of 4x the insurance coverage. Something I could not have done. All fees were nearly 50%........ Without the $$ it would have been much tougher to pay for the surgery. I figure there was a >75% chance my Kaiser surgeon (fourth one I interviewed) would have done a great job, however I just couldn't take the risk.

Since there are so many hip replacement surgeries done daily, there is a great disparity between surgical procedure and patient recovery. The procedure that has the best patient recovery is more specialized and a bit more difficult. There are way too many doctors that prefer to stay with the easier, more barbaric, method commonly practiced. Little concern is given to patient quality of life.

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post #976 of 1634 Old 08-21-2009, 09:11 PM
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Quote:
Originally Posted by leDahu View Post

Hi Ric,

I wrote very detailed explainations and procedure here

I also designed a spreadsheet which produces fast and very efficient results.

If any difficulty, I will translate the key points

Hello leDahu - I was so excited to see that post you linked me to. Yes! I am not the only one. Your screens shots and situation are identical to mine.

Your "original" (new bulb) gamma and mine when it was new looked the same. And furthermore after a few hundred hours my gamma graph turned exactly like yours!

And it is interesting that we both reached a similar technique to dial in gamma. Although it seems you chose to start at the top end and work your way down. Whereas I started at the bottom. And you do note that either direction should work.

The reason I chose to start at the bottom end is that it is much more sensitive to changes than the low end.

Interestingly I achieved a result that looks much like yours too. It was a lot of work. You noted 2 hours. Mine took much longer, although now that I have the technique down I am thinking I could do it in 2-3 hours.

Another trick I use is to save often (for instance exit and save changes after I do a few points, then come back and do some more, then save, etc and also copy these to another preset). This way if I mess up I do not have to start all over.

One possibly difference in our findings is that from the translated version I read it seems you were finding that it changed points both above and below the point you were working on? So if you were working on 60 it made changes to 50 and 70? I did not find that.

I found that it would change the level I was on, and one step BELOW. So for instance if I made changes on 10, it would impact readings on 5 and 10, but not 15. And if I made changes to 15, it would impact 10 and 15, but not 5 or 20.

So first I calibrated 5% using the 5% gamma setting to get it close but not perfect. Then I used the 10% gamma setting to fine tune 5% calibration.

Then I used 15% gamma setting to calibrate 10% level. Then 20% gamma setting to calibrate 15% level. Then 30% gamma setting to calibrate 20% level, and so forth.

The result was nearly perfect, except for the high end. At 90 and 95% my 2.2 target gamma falls off to more like 2.1 and 2.0. I concluded there was no way to get this 90-95% range flat, without then messing up 70-80%. So I settled for a perfectly linear 2.2 gamma from 5-80% with the fall off at the top end.

I am still wondering why the gamma changes so much after some bulb aging, compared to the new bulb. As you pointed out, its not just that the gamma becomes too low. But rather it has an inverted "Z"-like shape, with the low end having gamma way to high, the middle about on target, and the high end falling off significantly.

I don't mind that much to make this adjustment once. But I haven't remeasured since I made these changes months ago, and have since put another 100-200 hours on the bulb. I certainly hope that it hasn't shifted again! It seems to me that perhaps it would keep shifting.

Giving the complexity and time involved in this gamma calibration, I certainly would not want to have to repeat this every few hundred hours. I am not saying it is necessary, but rather I am questioning if it is. Have you put a few hundred hours on the bulb since you last calibrated and remeasured to see if it held nearly constant?

The spreadsheet looks amazing! Unfortunately I cannot really understand it in French. Any chance you could make an English version of it? It looks like it would be a huge help in the calibration process. I'm sure doing all this with a calculator wasn't helping the cause!
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post #977 of 1634 Old 08-21-2009, 10:02 PM
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I have also noticed the Z shape of the gamma curve on my unit which has about 250 hours on the bulb. I am glad you have seen the same as I was wondering if my unit had a problem

Perhaps I am not trying to get as flat a curve as you guys but I achieved a result of DE less than .7 across the scale in about a half an hour.

I used the latest version of CalMan and the attached custom layout. The absolute colour balance chart makes the task very easy. I first adjusted 80 IRE and 30IRE with a few iterations and then used the custom Gamma control

The absolute colour balance chart showed that the gamma was falling below about 50 IRE so I went from 5% to 50% putting in 4 clicks at 5% reducing up the scale as i got to 50

I then started back from 5% and did fine adjustment. I did not find too much interaction using this technique

The good part about the Absolute colour balance chart is it allows one to see colour as well as gamma errors at the same time so that the appropriate colour can be changed

 

Jvc 750.pdf 57.8759765625k . file
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post #978 of 1634 Old 08-22-2009, 05:23 AM
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I haven't sat down with my i1Pro in a long time. I have not had the time.

I have a lot of hours on my RS20 now, almost 1,300. I wonder how it measures?

I suspect that the gamma is too low on the high end because bright scenes look a little washed out lately.

I have some time today because the family is doing something without me. If I have the energy, I'll break out the equipment and report back.

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post #979 of 1634 Old 08-22-2009, 07:54 AM
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Quote:
Originally Posted by Lawguy View Post

I haven't sat down with my i1Pro in a long time. I have not had the time.

I have a lot of hours on my RS20 now, almost 1,300. I wonder how it measures?

I suspect that the gamma is too low on the high end because bright scenes look a little washed out lately.

I have some time today because the family is doing something without me. If I have the energy, I'll break out the equipment and report back.

I think you will likely see the same thing when you measure gamma. This is what leDahu measured at 160 hours on an HD750:



This is similar to what I and others have measured. I think its worth nothing that this is not a new phenomenon with the HD750 - I remember experiencing something like this with the RS1 (which I did nothing about because it didn't have tools to correct it nor do I have a scaler which such tools) and others have discussed this with the RS2 as well.

Quote:


If I have the energy...

Energy level 1 is needed to measure so you may want to start there to satisfy your curiosity. Though energy level 5 (mixed with a whole lot of patience) is required to correct it.

Actually though I am now thinking it can be done in about 2 hours time with the knowledge posted here and at leDahu's french post about how the controls interact and techniques to control things.

Let us know what you find and if you correct it, how it goes.
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post #980 of 1634 Old 08-22-2009, 09:20 AM
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After a few hours of frustrating experimentation, I came up with a system like the one described above for adjust gamma. I actually did a combination of both methods, iterating up and down; when going up, I adjusted the setting below my target, when going down, above. I adjusted to a 2.4 gamma curve, with 2.3 for 5 and 10 IRE to bring out a little shadow detail.
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post #981 of 1634 Old 08-22-2009, 11:43 AM
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Quote:
Originally Posted by lovingdvd View Post

I think you will likely see the same thing when you measure gamma. This is what leDahu measured at 160 hours on an HD750:



I am not surprised that the gamma would lower at the top end as the bulb ages. What does surprise me is that red holds up better than green or blue. That runs counter to what one would expect from a UHP bulb.

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post #982 of 1634 Old 08-22-2009, 01:34 PM
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Quote:
Originally Posted by TomHuffman View Post
What does surprise me is that red holds up better than green or blue. That runs counter to what one would expect from a UHP bulb.
Tom,
You should forget that point.
There is an 'accident' on the red channel.
And from the very beginning.
See attached file.

What is the theory behind 'gamma would lower at the top end as the bulb ages' ?

 

ref.zip 2.28125k . file
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post #983 of 1634 Old 08-22-2009, 01:48 PM
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Quote:
Originally Posted by lovingdvd View Post

I think you will likely see the same thing when you measure gamma. This is what leDahu measured at 160 hours on an HD750:

Yes. It looked the same. The good news is that my colors were still almost spot on after greyscale adjustments.

I find the gamma controls pretty easy to use. I have a little more work to do but after a half hour I have a reasonably flat 2.3 gamma. I just try to visualize what my curve looks like and where it needs to be corrected. In this case, I saw that the high end needed the most work so I just made the most adjustments at 100 and decreased them as I went down. You can see on the JVC how other points are affected so I just kind of "use the force" and back it up with my probe.

Affable Nitwit
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post #984 of 1634 Old 08-22-2009, 01:51 PM
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Gamma tweaking.
English version


I do prefer to start from the top end because this area is critical and very sensitive.

New version 1.2 available here

 

gamma HD750_eng.zip 17.4140625k . file

 

special gamma procedure.txt 2.0625k . file
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post #985 of 1634 Old 08-22-2009, 02:15 PM
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Quote:
Originally Posted by leDahu View Post

Gamma tweaking.
English version


I will translate the 'special procedure' soon.
In the meantime you can follow lovingdvd one.

I do prefer to start from the top end because this area is critical and very sensitive.

Wow leDahu - this looks incredibly useful! I bet this will cut my calibration time considerably. Thank you so much for not only writing this but then in translating it to English.

I am having a bit of trouble understanding some of the instructions. Lets follow your numbers as a working example. Take "line 7 - new gamma table". You have a 43.8 in there. Does this mean that ideally you would have 44 (closest to 43.8 that can be used) entered into the W value at 5%?

I think so, but became a little confused because I see your 55 as the value for 10% and that seems very low (my value calibrated for a 2.2 gamma is 102). But perhaps this is because your gamma reading is at 2.0 for 10%? Maybe you can "talk us through" a hypothetical example of calibrating a couple % levels, referencing what is in the spreadsheet as the numbers in the example?

Also I was wondering about your comment in the spreadsheet about repeating this for green, red and blue as necessary. When I did my calibration I FIRST used the R/G/B in the gamma to make the grayscale tweaks. Then when I did my gamma tweaks I used only W, not touching RGB. Can you elaborate on what you are meaning in the spreadsheet about that and how that factors into the gamma calibration?

Thanks again!
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post #986 of 1634 Old 08-22-2009, 04:19 PM
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leDahu - also I meant to ask you something else... What you do as far as these target numbers go? Just get as close as you can? For instance say your spreadsheet says to use 260. The controls may only allow setting at 252 or 270 and so forth - so you just go with whatever is closest? Too bad the RS20 doesn't just accept whatever value you set. Things would be sooo much easier...
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post #987 of 1634 Old 08-23-2009, 04:17 AM
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Thanks, LeDahu!

Great procedure.

Having now watched some material, after touching up my gamma, it shows that the drift that I experienced had a noticable impact on the picture quality, particularly on the high end.

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post #988 of 1634 Old 08-23-2009, 04:59 AM
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Originally Posted by lovingdvd View Post

The reason I chose to start at the bottom end is that it is much more sensitive to changes than the low end.

Yes, but the current concern is at the top end.
Therefore one should correct this area first.
Second, at the top end -95- the gradation stepping is very low (about 2 notches for 0.1 gamma variation) whereas at 5 IRE it is high (about 6 for the same gamma variation). So endind up the job at the bottom end is easier and the compromise has less impact.

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Another trick I use is to save often (for instance exit and save changes after I do a few points, then come back and do some more, then save, etc and also copy these to another preset). This way if I mess up I do not have to start all over.

I abandoned this: the procedure is reliable enough.
I just keep track of the values.
I used to run the full grayscale and correct everything in one go.
Working point after point is possible but switching between HCFR, Excel and the JVC is long and source of mistakes
At the curve end it's different

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One possibly difference in our findings is that from the translated version I read it seems you were finding that it changed points both above and below the point you were working on? So if you were working on 60 it made changes to 50 and 70? I did not find that.

Yes it is.
That is why it is possible to apply the same procedure downward and upward.
In some occasions it happens that one next point does not move probably because the JVC does not need to change it.
JVC tries always to smooth the curve.
It also happens that one next point moves in the opposite direction!
This is puzzling.

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The result was nearly perfect, except for the high end. At 90 and 95% my 2.2 target gamma falls off to more like 2.1 and 2.0. I concluded there was no way to get this 90-95% range flat, without then messing up 70-80%. So I settled for a perfectly linear 2.2 gamma from 5-80% with the fall off at the top end.

It is not easy. Even when proceeding from the top end.
I envisage another approach...

Also, the low sensitivity and fluctuation readinds of the probes in the low range does not help.

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I am still wondering why the gamma changes so much after some bulb aging, compared to the new bulb. As you pointed out, its not just that the gamma becomes too low. But rather it has an inverted "Z"-like shape, with the low end having gamma way to high, the middle about on target, and the high end falling off significantly.

Looking around I notice that there is no rule with ageing.
Some show the trend very early and others later.
The shape is identical

On another hand it seems that the 3 panels shift about the same way in time

It looks like a kind of non-linearity problem at the top end.
The luminance curve seems to be bent as from 90 IRE.
I did an experiment. With the HCFR probe one can get the low level sensor reading. I edited the data and increased the values at 100 IRE by 1.7%.
As a result the gamma curve straightened up nicely.

Also, I reversed the gamma tables and found that they are not designed for a linear gamma at both ends. That's why I'm using the tables as reference in my spreadsheet. Since I changed my mind.
Might be done in order to compensate the native panel behaviour.

I can't imagine that the bulb alone is responsible for that.

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I don't mind that much to make this adjustment once. But I haven't remeasured since I made these changes months ago, and have since put another 100-200 hours on the bulb. I certainly hope that it hasn't shifted again! It seems to me that perhaps it would keep shifting.
Giving the complexity and time involved in this gamma calibration, I certainly would not want to have to repeat this every few hundred hours. I am not saying it is necessary, but rather I am questioning if it is. Have you put a few hundred hours on the bulb since you last calibrated and remeasured to see if it held nearly constant?

I'm almost certain that a bulb change will not recover the initial gamma performances, and that the shift has a limit even if it takes more or less time to be achieved. And that the limit value is nearly the same for all the units. Don't ask me why

As Tom who insisted many times, I agree that an accurate grayscale calibration including gamma is THE key factor. Mainly for 3D perception and tonic images.
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post #989 of 1634 Old 08-23-2009, 05:06 AM
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Originally Posted by Lawguy View Post

Thanks, LeDahu!

Great procedure.

Having now watched some material, after touching up my gamma, it shows that the drift that I experienced had a noticable impact on the picture quality, particularly on the high end.

You're wellcome,

For making comparisons would you please edit your gamma graph at 1300 hours or the values at different IRE
thanks
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Originally Posted by leDahu View Post

You're wellcome,

For making comparisons would you please edit your gamma graph at 1300 hours or the values at different IRE
thanks

No problem.

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