Video Bias Lighting (SMPTE Recommended Practice- CIE D65/6500K White Light Only) - Page 61 - AVS Forum
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post #1801 of 1810 Old 03-24-2009, 06:15 AM
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Thanks for the reply, Beach, looks like the veracity of your information is being questioned!!
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post #1802 of 1810 Old 03-24-2009, 08:07 AM
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Originally Posted by rstand View Post

Thanks for the reply, Beach, looks like the veracity of your information is being questioned!!

Corwin is the real troll who refuses to accept any scientific fact except for those associated with a company in question as can be seen from his past posts. If a Company says it about their product, its true in eyes.

He is a classic example of what went wrong in DC and Wall Street because the lemmings followed blindly.

Yet, as he does not believe that the bias light he purchased is not D65, he continues to make up responses that results are a results of photoshop and even conveniently overlooks posts concerning the same:

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Originally Posted by GeorgeAB View Post

Sample to sample swings in color from our various lamps over the years have ranged about +/- 500K. Several independent readings from customers, in several nations, have reported better results than yours. I have seen readings similar to yours in some random samples. The exception has been the lamp we use in our Ideal-Lume Pro model. It's much more precise and consistent.

What instrument did you use, with what methodology, and under what ambient conditions? If you can find any tolerances stated in the technical literature for bias lighting, I would be happy to have the information. The closest I've come to anything is from the companion document, SMPTE RP167-A.14, which only states tolerances for SMPTE C primaries being +/- 0.005 x/y. Our Pro model performs within those tolerances from D65.

As was noted earlier, I had a regular IL which measured between 5800-5900K that had been on for roughly 1500 hours.

A brand new IL Standard was tested and the results where very spot on the D65. However, within 100 hours it had fallen 100K and in less than 500 hours it was well below 6000K.

I have now seen and recorded the same results on 4 different IL purchased at random times over the past 12 months.

JRCorwin is apparently mad that someone got something that was more accurate than he did for a cheaper price.

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Originally Posted by jrcorwin View Post

He didn't pay a higher price. He spent $20. He paid less for an inferior product. Basically, you get what you pay for. Another $40 for the Ideal-Lume would be a wise choice and investment.

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post #1803 of 1810 Old 03-24-2009, 08:38 AM
 
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Originally Posted by BeachComber View Post

Corwin is the real troll who refuses to accept any scientific fact except for those associated with a company in question as can be seen from his past posts. If a Company says it about their product, its true in eyes.

He is a classic example of what went wrong in DC and Wall Street because the lemmings followed blindly.

Yet, as he does not believe that the bias light he purchased is not D65, he continues to make up responses that results are a results of photoshop and even conveniently overlooks posts concerning the same:



As was noted earlier, I had a regular IL which measured between 5800-5900K that had been on for roughly 1500 hours.

A brand new IL Standard was tested and the results where very spot on the D65. However, within 100 hours it had fallen 100K and in less than 500 hours it was well below 6000K.

I have now seen and recorded the same results on 4 different IL purchased at random times over the past 12 months.


Yet again, what scientific facts have you offered? You have offered no facts...none...zilch. You have offered mere theory. Just some random screen caps which have not been verified and tests which which were conducted under unknown conditions/circumstances. It's likely that your testing ability and lack of knowledge on the issue are to blame for your test results.

We know who supports the Ideal-Lume claims:

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Professional client list: the National Institute for Standards and Technologies(NIST); the Imaging Science Foundation(ISF); Joe Kane Productions; Display Mate Technologies; CNET Labs; Stewart Filmscreen; the Metropolitan Museum or Art; Industrial Light and Magic(ILM); THX, Ltd.; Deluxe; E-Film; Universal Studios; CinRam; Electronic Arts(EA); Image Entertainment; Radical Games; Factor5; High Moon Studios; Zombie Studios; Deluxe Digital Studios; Microsoft Corp; Audyssey Laboratories.

Who supports your claims?

Your "facts" have been proven to be false before. Flaking LED's?

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Originally Posted by BeachComber View Post

JRCorwin is apparently mad that someone got something that was more accurate than he did for a cheaper price.

According to whom exactly? Some random person on a message board with test results that have not been verified. Keep trying...
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post #1804 of 1810 Old 03-24-2009, 08:45 AM
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Originally Posted by jrcorwin View Post

Yet again, what scientific facts have you offered? You have offered no facts...none...zilch. You have offered mere theory. Just some random screen caps which have not been verified and tests which which were conducted under unknown conditions/circumstances.

We know who supports the Ideal-Lume claims:

Who supports your claims?

As noted above, GeorgeAB admitted he had seen similar results.

Furthermore, those listed above support the $300 PRO IL, not the $40 version that you and others are buying.

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Originally Posted by jrcorwin View Post


Your "facts" have been proven to be false before. Flaking LED's?

According to whom exactly? Some random person on a message board with test results that have not been verified. Keep trying...

I guess you think that ghbliss and Spectracal are just random people and businesses on message boards?
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post #1805 of 1810 Old 03-24-2009, 08:50 AM
 
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Originally Posted by BeachComber View Post

As noted above, GeorgeAB admitted he had seen similar results.

Furthermore, those listed above support the $300 PRO IL, not the $40 version that you and others are buying.



I guess you think that ghbliss and Spectracal are just random people on message boards?

...deflecting the attention away from your own claims I see. Predictable. You tend to make wild claims, yet lack the proper information to back them up. Reminds of the flaking LED's issue again.

Note: I never mentioned a particular model. I didn't realize I would have to point out something to you that is so simple.
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post #1806 of 1810 Old 03-24-2009, 11:04 AM
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I guess you think that ghibliss and Spectracal are just random people on message boards?...deflecting the attention away from your own claims I see. Predictable. You tend to make wild claims, yet lack the proper information to back them up. Reminds of the flaking LED's issue again.

Note: I never mentioned a particular model. I didn't realize I would have to point out something to you that is so simple.

jrcorwin,

What specifically do you contend to be a "Wild Claim" from the post of beachcomber? He is using a high bandwidth spectroradiometer as well as a NIST traceable White Reflectance standard to measure the lamps with. This happens to be the proper methodology to use and provides accurate repeatable results. The data he has provided the people viewing this thread has been completely above board and is the only independent scientific analysis submitted regarding the accuracy or lack thereof of a variety of lamps being used for display back-lighting applications.

Beachcomber has been kind enough to take it upon himself at considerable cost to purchase a wide variety of lamps to test and provide everyone with his findings. All of the lamps were tested in the same manner using the same high end reference test equipment with all of the data displayed for everyone to see. The majority of the lamp manufacturers do not even provide this type of data so I fail to see precisely what it is that you are questioning regarding the validity of the data.

Who do you feel is more impartial to perform independent testing of a product such as this that you would trust? Most manufacturers lack the very tools needed to perform the very tests that beachcomber has provided us with. He has been impartial throughout the testing and provided strightforward factual documentation which I find highly credible. Your comments seem to be quite harsh to say the very least since you have not provided one iota of factual data regarding the entire back lighting subject. Your pointed comments and complete lack of understanding of the spectral data plots which have been provided show that you are unwilling to take accept the information constructively and use the forum as a learning tool as many users do.

Unless you can show a single reason why the information provided is not credible then I would respectfully request that you refrain from commenting as you have nothing constructive to offer the members of the forum following this thread!
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post #1807 of 1810 Old 03-24-2009, 11:45 AM
 
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Originally Posted by ghibliss View Post

jrcorwin



jrcorwin,

What specifically do you contend to be a "Wild Claim" from the post of beachcomber? He is using a high bandwidth spectroradiometer as well as a NIST traceable White Reflectance standard to measure the lamps with. This happens to be the proper methodology to use and provides accurate repeatable results.

I don't know that and neither do you. The validity of his tests were verified by....no one.

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Originally Posted by ghibliss View Post

The data he has provided the people viewing this thread has been completely above board and is the only independent scientific analysis submitted regarding the accuracy or lack thereof of a variety of lamps being used for display back-lighting applications.

The data has been used merely to attack the integrity of one and only one person. Rather than attempting to assist other members, he has chosen to attack one in particular at every available opportunity.

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Originally Posted by ghibliss View Post

Beachcomber has been kind enough to take it upon himself at considerable cost to purchase a wide variety of lamps to test and provide everyone with his findings. All of the lamps were tested in the same manner using the same high end reference test equipment with all of the data displayed for everyone to see.

Again, the validity of this is unknown.

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Originally Posted by ghibliss View Post

Unless you can show a single reason why the information provided is not credible then I would respectfully request that you refrain from commenting as you have nothing constructive to offer the members of the forum following this thread!

BeachComber has a history of making wild claims without providing credible information to back those claims up. Outside of this topic, the recent LED flaking topic comes to mind...

To bring this full circle. This is the comment that he has chosen to use against me:

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Originally Posted by jrcorwin View Post

He didn't pay a higher price. He spent $20. He paid less for an inferior product. Basically, you get what you pay for. Another $40 for the Ideal-Lume would be a wise choice and investment.

You'll notice that my comment about the other product being inferior...had absolutely nothing to do with 6500K. I didn't even mention it. My opinion all along has been that the Ideal-Lume products are superior for more than one reason. Two of the main reasons being build quality and versatility.

I have stated this opinion many times. BeachComber has spouted off several times about how I refuse to accept scientific fact...which is false. Show me actual scientific fact or proof which disproves the opinion I just stated and I will gladly accept it. Show me why I am not able to have my own opinion on this matter rather than accepting BeachComber's opinion as an absolute truth.

You should also know that this is based on an argument from more than two months ago. I have attempted to bury the hatchet with him several times and find some sort of common ground. He has outright refused to do so...wouldn't even consider it. He has clung to this ridiculous claim that I refuse to accept scientific fact and that is false.
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post #1808 of 1810 Old 03-24-2009, 07:00 PM
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Quote:
Originally Posted by ghibliss View Post
jrcorwin



jrcorwin,

Quote:


What specifically do you contend to be a "Wild Claim" from the post of beachcomber? He is using a high bandwidth spectroradiometer as well as a NIST traceable White Reflectance standard to measure the lamps with. This happens to be the proper methodology to use and provides accurate repeatable results.
I don't know that and neither do you. The validity of his tests were verified by....no one.


As a point of reference I can personally attest to the accuracy of the instrument which beachcomber tested the backlight lamps with as my company manufactured and calibrated the piece individually which is NIST certified. The reference instruments used in the calibration process are all NIST traceable instruments as well!

If you have followed the course of this thread you may have viewed comparative data collected by beachcomber that included a spectral distribution chart showing the performance of each of the lamps which was quite revealing as to how they each perform in real life. More then one document has been posted outlining what the ideal spectral response of the lamps should be so determining which lamp lies closest to the reference plot should have been quite easy for even a lay person to deduce.

Quote:


You'll notice that my comment about the other product being inferior...had absolutely nothing to do with 6500K. I didn't even mention it. My opinion all along has been that the Ideal-Lume products are superior for more than one reason. Two of the main reasons being build quality and versatility.

I have stated this opinion many times. BeachComber has spouted off several times about how I refuse to accept scientific fact...which is false. Show me actual scientific fact or proof which disproves the opinion I just stated and I will gladly accept it. Show me why I am not able to have my own opinion on this matter rather than accepting BeachComber's opinion as an absolute truth.

You should also know that this is based on an argument from more than two months ago. I have attempted to bury the hatchet with him several times and find some sort of common ground. He has outright refused to do so...wouldn't even consider it. He has clung to this ridiculous claim that I refuse to accept scientific fact and that is false.

You state that you feel that Ideal Lume products are superior due to build quality and versatility! Ideal Lume is a turn key solution which provides a good option for a number of users to turn to. The actual performance of the lamps being sold which Beachcomber tested are sold in most cases as a "lamp only" requiring the user to supply their own fixture, ballast etc. Beachcombers conducted tests strictly on lamps where I find it very difficult for you to make a claim as to how much better one lamp is over the other without performing extensive testing.

It seems that you will not believe the test results unless Price Waterhouse or some other accredited independent firm oversees all testing as well as the handling of the measurement data. Please specify exactly what is required for you to find any test data to be accurate and reliable. The data provided seems to be acceptable to the majority that are viewing this thread.

Quote:


He has clung to this ridiculous claim that I refuse to accept scientific fact and that is false.

It would appear that beachcomber is correct that you are unwilling to accept scientific fact as his testing data is quite conclusive and quite scientific as well. Very few users on this forum have a White reflectance standard which to measure the light from the lamps properly with let alone a high spectral bandwith and high resolution spectroradiometer.
LL
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post #1809 of 1810 Old 03-24-2009, 07:41 PM
 
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Originally Posted by ghibliss View Post

jrcorwin
Quote:
Originally Posted by ghibliss View Post
jrcorwin



jrcorwin,




As a point of reference I can personally attest to the accuracy of the instrument which beachcomber tested the backlight lamps with as my company manufactured and calibrated the piece individually which is NIST certified. The reference instruments used in the calibration process are all NIST traceable instruments as well!

If you have followed the course of this thread you may have viewed comparative data collected by beachcomber that included a spectral distribution chart showing the performance of each of the lamps which was quite revealing as to how they each perform in real life. More then one document has been posted outlining what the ideal spectral response of the lamps should be so determining which lamp lies closest to the reference plot should have been quite easy for even a lay person to deduce.



You state that you feel that Ideal Lume products are superior due to build quality and versatility! Ideal Lume is a turn key solution which provides a good option for a number of users to turn to. The actual performance of the lamps being sold which Beachcomber tested are sold in most cases as a "lamp only" requiring the user to supply their own fixture, ballast etc. Beachcombers conducted tests strictly on lamps where I find it very difficult for you to make a claim as to how much better one lamp is over the other without performing extensive testing.

It seems that you will not believe the test results unless Price Waterhouse or some other accredited independent firm oversees all testing as well as the handling of the measurement data. Please specify exactly what is required for you to find any test data to be accurate and reliable. The data provided seems to be acceptable to the majority that are viewing this thread.



It would appear that beachcomber is correct that you are unwilling to accept scientific fact as his testing data is quite conclusive and quite scientific as well. Very few users on this forum have a White reflectance standard which to measure the light from the lamps properly with let alone a high spectral bandwith and high resolution spectroradiometer.

You can say it as many times as you wish, but it won't make it true. You have no way of knowing if his test results are valid. You do not know for a fact if those instruments were used and/or used properly. You are simply taking his word for it and nothing more. I do not question the accuracy of your product. I question the manner in which it was used...if it was even used at all. No one was there to validate these results. I have been give absolutely no reason why I should trust these results.

My opinion about the ideal-lume was posted before his claims were made...not after. My opinion has nothing to do with his "tests" or claims.

His results are conclusive only if you trust the manner in which the tests were conducted. Based on his conduct within this thread and others...I have no reason to. Again, he has made other claims as well. Claims which were not based on any evidence and he quickly slipped away once he was proven to be wrong without ever acknowledging it. It's a simple pattern of behavior. You must keep in mind that when I stated my opinion...I mentioned nothing about the 6500K standard. That was BeachComber's assumption and he decided to attack without taking the time to review the situation. Again, a pattern.

Yes, I believe that the Ideal-Lume is superior based on build quality, versitility, and other such factors. You point out that he tested lamps only. I'm well aware of this. I stated my opinion independent from his claims. My opinion had/has nothing to do with his claims. My opinion was not only about the lamps, but the entire product being offered. You would have been aware of this had you been involved in the conversation. You were not and seem to be here because he cannot defend himself. I am more than welcome to my own opinions...as are you and BeachComber as well. The problem arises whenever he attacks me for having an opinion at all rather than proclaiming his opinion to be absolute fact.

You're defending someone who has done the following: Sought me out in other threads regarding very different topics...having nothing to do with bias lighting...only for the purpose of attacking me for not agreeing with his opinion. He has done this more than once. In this situations he does not attempt to discuss the topic at hand, but instead focuses on attacking me. I am the one who has attempted to offer an olive branch serveral times and I have been turned down each and every time.

The bottom line is this, I believe that we should all be free to have our own opinions and be comfortable with our very own buying decisions. BeachComber seems to believe that his opinion is the only one which matters and any purchase he does not agree with is rubbish. That is the behavior you are defending.
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post #1810 of 1810 Old 03-24-2009, 08:51 PM
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Originally Posted by rstand View Post

Thanks for the reply, Beach, looks like the veracity of your information is being questioned!!

Well, I guess we'll see.

Interesting how G. Alan Brown takes the word of a THX Graduate in Denmark with a $500 meter - yet JRCorwin disputes the word of one in the USA with $10k worth of far superior equipment who only works with Broadcast Operations and has measured light temp in many News Studios.

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Originally Posted by GeorgeAB View Post

Please define "close," and where do you see any statement in the ad that claims any color temperature? Are you guessing? Over recent years, every white LED product I have purchased and tested has measured anywhere from 7500K to 16,000K. These were all claiming to be 6500K or within 500K of that color temperature.

The only exception has been the Ikea white Dioder product, which measured 5200K. This was reported to me by a THX calibrator in Denmark. Ikea does not make any color temperature claim in their online ad. His reading of an Ideal-Lume Panelight came in at 6540K.

I'm growing weary of spending money and time on uncovering repeated marketing hype, uninformed guesswork, and outright lies about so-called 6500K white LED products. If anyone wants to order these, test them with reliable instruments and report back on your findings, I'll take an interest. Until that happens, I'll assume they are no where near the right color, likely way too blue, especially since they don't even claim to be correct.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"

As can be seen from the fL output, the Orangetree product puts out much less light than any of the others because of LEDs spaced every 2 inches. This is good in that it gets you much closer to 10 IRE on a set, but the question can become does it put out enough to provide that in some instances.
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