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Raw & Post Processing, Printing => Colour Management => Topic started by: Frans Waterlander on June 20, 2013, 02:36:40 pm

Title: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 20, 2013, 02:36:40 pm
Some people say that SoLux bulbs fail to meet their CCT spec by up to 1000K and some say they meet specs. If you have test results one way or the other, I'd like to hear from you, because I'd like to set the record straight. I have no connection to SoLux, other than using their bulbs in my digital darkroom and being satisfied with their performance.

My own measurements and information supplied by SoLux and the Intertek test lab indicate that SoLux bulbs meet their color temp spec within +/- 200K. SoLux maintains that in all cases where they got an opportunity to review the test set up when out of spec results were reported, they showed incorrect test setups related to light contamination from the backs of the bulbs or otherwise and/or incorrectly powering the bulbs. After corrections were made the bulbs tested within spec.

If you tested out of spec, did you work with Phillip Bradfield or Kevin McGuire at SoLux to resolve the issue and what was the result?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 20, 2013, 05:25:07 pm
(http://www.digitaldog.net/files/Solux4700K.jpg)

The above as I mentioned at PhotoNet is to be expected (the numbers don't mean much, they are correlated). This CCT4700K lamp, inserted within a Solux lamp housing by their design fails as it's off by CCT 451K. So what?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: xpatUSA on June 20, 2013, 06:20:28 pm
Solux's website is a bit puzzling. Apparently their PAR lamp "reproduces the full color spectrum of natural daylight at 3500K!" (my emphasis).

Honest, see here: https://www.solux.net/cgi-bin/tlistore/soluxparbulbs.html

At least 2000K off, right from the git-go  ;)

Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 20, 2013, 06:38:44 pm
So what? If you measure a product to not meet specs and you publish those results, decency dictates to work with the seller. And doing that before publishing your results would be even better.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 20, 2013, 06:58:47 pm
So what? If you measure a product to not meet specs and you publish those results, decency dictates to work with the seller.

No it doesn't. I'm not buying their values because they are CCT. Just as I don't buy a spec that says the light is D50: there's only one device that can produce that and it's really far away plus D50 is a number of measurements made across the planet to boot.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Schewe on June 20, 2013, 08:00:35 pm
Apparently their PAR lamp "reproduces the full color spectrum of natural daylight at 3500K!"

That means that the PAR lamp puts out a full spectrum (spectral power distribution or SPD) of daylight with a color temp of 3500ºK. Yes, that's 2000ºK less than 5500ºK, but the spec says 3500ºK. They also have 12v lamps that range from 3500ºK to 4100ºK, 4700ºK and 5000ºK.

Back to the OP a couple of hundred degrees difference is negligible when used as a viewing light because your eyes will compensate (white adaptation). A couple hundred degrees would be more relevant when talking about a light designed to shooting film or digital. But it's really the evenness of the SPD that matters there...plus, it's not hard to white balance a few hundred K.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Jack Varney on June 20, 2013, 10:06:26 pm
When you tire of specs just try them and compare them to other lamps. They work for me.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 20, 2013, 10:09:14 pm
When you tire of specs just try them and compare them to other lamps. They work for me.

Exactly! They have a lovely spectrum and light quality. The numbers are pretty meaningless (hence the 5000K units which are 4700K, driven hotter to burn out faster and cost you more).
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Schewe on June 20, 2013, 10:45:32 pm
The numbers are pretty meaningless (hence the 5000K units which are 4700K, driven hotter to burn out faster and cost you more).

Well, the numbers have meaning but they are relative...I have a GTI light box which I've re-lamped with D65 bulbs which are kinda cool (but match my displays) and I've got a Solux task lamp with 4700ºK bulbs which are a bit warm. Using the two I can evaluate near daylight and near tungsten and compare the prints under both. The advantage of the Solux is that they have a better, less spiky SPD. I also have a 3500ºK bulb I can pop in if I need a eval closer to tungsten (I rarely use it).
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 20, 2013, 11:05:01 pm
OK Andrew,

Let me get this straight: SoLux says the 4700K bulb should have a CCT of 4700K +/- 200K. You measure a CCT of 4249K, declare that they fail to meet their published specifications, publish your results without talking to SoLux and apparently are not planning to do so, and you say so what? This, to me, is unbelievable. This, what looks like a devil-may-care attitude, would never fly in my career in the electronics industry in R&D, marketing and quality engineering.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Tim Lookingbill on June 21, 2013, 02:22:13 am
OK Andrew,

Let me get this straight: SoLux says the 4700K bulb should have a CCT of 4700K +/- 200K. You measure a CCT of 4249K, declare that they fail to meet their published specifications, publish your results without talking to SoLux and apparently are not planning to do so, and you say so what? This, to me, is unbelievable. This, what looks like a devil-may-care attitude, would never fly in my career in the electronics industry in R&D, marketing and quality engineering.

You have a career in electronics?! OH JOY!

Could you R&D and design decent MR16 circuitry into a task lamp whose 110v>12v power converter won't crap out after 40 hours of use? I mean could ya'?! REALLY?! Could ya?! That would really help a small group of photographers out who bought a Solux bulb but can't find reliable lamps to drive it.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 09:13:18 am
Let me get this straight: SoLux says the 4700K bulb should have a CCT of 4700K +/- 200K. You measure a CCT of 4249K, declare that they fail to meet their published specifications, publish your results without talking to SoLux and apparently are not planning to do so, and you say so what?

I do. Not just I as you know.

At least two other's from the ColorSync list, one a respected color scientist (Robin Myers who wrote SpectraShop) with a $13,000 spectroradiometer and i1Pro who's data correlated well with mine and others. LuLa audience: This is all known to Franz and I'll copy and paste the same data from the CS list that Franz saw below. When presented this data, Franz said they (and presumably now I) did the measurements wrong. Besides what the marketing department at Solux has placed in their spec sheet, the only other person to get a value that's within what Solux provides is Franz, using a 10 year old Minolta Color meter!

To answer your question Franz, I think you are confusing marketing spec's with science here. It is not up to us to disprove Solux's numbers although we have done so to a degree (at least three independent end users reported the numbers don't jive with the spec's). It's up to Solux to provide an exact process used and for us to then correlate or not. They have not done this! They have the ability to post here, PhotoNet where you started all this, and more appropriately on the ColorSync list. They didn't in 2009 after Robin and other's posted their findings! Why don't you find out what instrument they used, the software used, and the exact testing process used to get their numbers? 

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This, what looks like a devil-may-care attitude, would never fly in my career in the electronics industry in R&D, marketing and quality engineering.

It is you sir that has the devil may care attitude. You don't have the equipment appropriately to measure the SPD and produce the CCT values. You haven't provided any testing methodology Solux used to get their values but you've now posted about this in three forums and when others using at least the correct instrumentation provide values that don't jive with Solux, you have the nerve to tell us we are doing the measurements wrong! You blindly accept the marketing driven spec sheet of a company who's products everyone so far agree's is a good product and who all dismiss the values. It's a shocking attitude from someone who says he's got a bkgnd in the electronics industry. Worse, far worse is this is all due to your article, hosted on the Solux site that states we should all be using Solux 5000K bulbs and calibrate our displays to 5000K, after which we'll get a match. Anyone else here on LuLa find that approach doesn't work?

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Subject: Re: Solux Bulb color temperature
From: Robin Myers
Date: Tue, 17 Feb 2009
Here are the CCT results from measuring a Solux 4700K bulb, and two Solux 5000K bulbs (one with clear sides, one with black sides). The measurements were made 1 m from the front of the fixture to the measuring devices aperture.

i1 Pro with Ambient filter

Solux 4700 50W 36-degree 4304K +-4K
Solux 5000 35 W 36-degree Clear 3974K +- 3K
Solux 5000 35 W 36-degree Black 4428K +-7K
PR-655 with CR-655 Cosine Corrector

Solux 4700 50W 36-degree 4431K +-2K
Solux 5000 35 W 36-degree Clear 4025K +- 4K
Solux 5000 35 W 36-degree Black 4528K +-2K

With only one sample each of the 5000K bulbs, it was not possible to double-check the 5000K Clear bulb, but it is apparent that the 5000K bulb is not right. I suspect it is a mismarked lower Kelvin bulb or a bad bulb.
Otherwise, the i1 Pro and the PR-655 agree. There were two different setups, at two different locations but the light fixture was the same and the bulbs were the same for both sets of tests. The CCT was calculated with SpectraShop 3 (to be released later this week, hopefully) and the CCT results of 5 to 6 measurements of each bulb were averaged.
The calculated CCTs do not agree with the expectation based on the manufacturer's marketing.
In comparing the emission spectrums, the i1 Pro and PR-655 agree fairly well. Both of them have a general shape similar to the D50 curve, but much smoother. There are several small peaks in the D50 spectrum absent from the measured Solux spectra. The manufacturer has claimed a spectral shape similar to D50 and it is a reasonable approximation.
In Ken Fleisher's original post, he reported a CCT of 4450K for the Solux 4700K bulbs and the results above agree with the lower than claimed CCT value (if you believe the "4700 Kelvin" on the bulb's box means CCT).

Robin Myers

And

Quote
Subject: RE: Solux Bulb color temperature
From: "Tim Vitale" <email@hidden>
Date: Tue, 17 Feb 2009 11:21:24 -0800
I have four Solux 4700 K 36deg floods that are about 1-2 years old
with 100-300 hours (or so) on them. The only variation can be hours
of use. I will be ordering a new batch quite soon. If you are still
interested get back to me in 7-10 days and I'll report the newest
findings.
# 1 = 4363 K
# 2 = 4550 K
# 3 = 4307 K
# 4 = 4456 K
They were measured with an i1 Rev D (UV incl) in Emissive-Light mode,
using Robin Myers SpectraShop.
As Robin said earlier, I have never found a bulb to be the actual
stated CCT. All except one.

I just rebuilt my light bleaching set-up and purchased a $120, 250 W,
Metal Halide "Hostile - Blue" lamp (Eye Lighting, Japan) that outputs
6530 K +/- 35, with 16500 Lux, about 20" from the bulbs; less than 1
hour old. As one would expect, it is a bit spiky, but not as bad as
normal Metal Halide lamps. They label it 6500K in the PDF;
http://www.eyehortilux.com/blue.html; PDF <EQS-N-52-78-57799[1].pdf>.
Tim Vitale

Title: Re: Do SoLux bulbs meet color temp specs?
Post by: xpatUSA on June 21, 2013, 12:25:22 pm
That means that the PAR lamp puts out a full spectrum (spectral power distribution or SPD) of daylight with a color temp of 3500ºK. Yes, that's 2000ºK less than 5500ºK, but the spec says 3500ºK.

I suppose that daylight, in it's broadest sense, exists between sun-up and sun-down.

However, a brief Google provides hundreds, if not thousands, of statements that "daylight" is normally taken as between 5000K and 7500K.

However, Solux does explain how a CCT of 3500K can be considered as 'daylight' when occurring indoors between 194 and 2,153 lux.

Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 12:27:56 pm
However, Solux does explain how a CCT of 3500K can be considered as 'daylight' when occurring indoors between 194 and 2,153 lux.

But will Franz accept that especially considering the source?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: xpatUSA on June 21, 2013, 12:42:21 pm
But will Franz accept that especially considering the source?

I imagine he should, provided that the CCT is what Solux says it and is within Solux's stated tolerances.

As far I can see, Frans' gripe is not about what constitutes 'daylight' which appears to be whatever anybody says it is ;-)

Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 21, 2013, 01:49:49 pm
Andrew wrote: "Why don't you find out what instrument they used, the software used, and the exact testing process used to get their numbers?"

Come again? I suggested, several times, that you work with SoLux directly as you know what your test setup and method are and SoLux knows theirs. And yes, I think you have an obligation to at least try to resolve this issue since you and others are so eager to publish results that claim the products don't meet published specifications. That's a big deal in my book.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 02:00:06 pm
Andrew wrote: "Why don't you find out what instrument they used, the software used, and the exact testing process used to get their numbers?"
Come again? I suggested, several times, that you work with SoLux directly as you know what your test setup and method are and SoLux knows theirs. And yes, I think you have an obligation to at least try to resolve this issue since you and others are so eager to publish results that claim the products don't meet published specifications. That's a big deal in my book.

Franz, I don't care, and only you dismiss other's data that correlates and disproves Solux marketing. Only you thus far have measured data that correlates somewhat closely with them, using a pretty piss poor product to do so. You asked a question here yourself: Do SoLux bulbs meet color temp specs? They do not. Multiple people have told you this. At PhotoNet, you suggested we measured the Solux incorrectly didn't you? Since you don't have the proper equipment anyway, and since you don't know how Solux did their measurements, how as an 'engineer' can you suggest Robin, Tim and I all did this incorrectly? We are very secure in our findings. IF you or Solux don't agree, and you've said that in print, it is up to you to prove the data collected is incorrect and you haven't done this. On the other hand, several of us, using Spectrophotometer's that range from a few thousands dollars to one over $13K all have data which suggests YOU and Solux are the one's off here. But none of us care, only you have come to no less than three sites to suggest the values Solux uses are correct and worse, that we should all be using their 5000K bulbs and then calibrating our differing displays using differing instruments to 5000K which doesn't wash.

I'd be happy to work with Solux if they want to pay me to do so. Otherwise, based on the data I and other's have collected, I have no reason to go any further. You on the other hand don't seem to be satisfied until someone, somewhere tells you they came up with the same data you did, and maybe with something like a 10 year old Minolta color meter, they will. You'll probably not find them here or on the CS list, folks here are a bit more sophisticated in terms of the equipment and testing methodology they used to come to conclusions.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 02:03:23 pm
And yes, I think you have an obligation to at least try to resolve this issue since you and others are so eager to publish results that claim the products don't meet published specifications.

And YOU have an obligation to prove at least three of us who all produced similar results are wrong as you stated at PhotoNet! You haven't done this and I don't think you can. You are the one who asked about the differences, not myself, or Solux. The obligation is entirely on you!
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: xpatUSA on June 21, 2013, 02:07:35 pm

You have a career in electronics?! OH JOY!

Could you R&D and design decent MR16 circuitry into a task lamp whose 110v>12v power converter won't crap out after 40 hours of use? I mean could ya'?! REALLY?! Could ya?! That would really help a small group of photographers out who bought a Solux bulb but can't find reliable lamps to drive it.

No need to candy-coat it, Tim, let's really pound on the noob til he goes away . . .
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 02:10:49 pm
No need to candy-coat it, Tim, let's really pound on the noob til he goes away . . .

Tim's over on PhotoNet so he's aware of the various issues with Franz if you will. If you really want to know the various rabbit holes we've been down, there's this:

http://photo.net/digital-darkroom-forum/00bjDL

When that got as far as it did, he started this post there (and here and on the ColorSync list):

http://photo.net/digital-darkroom-forum/00bkvN
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: xpatUSA on June 21, 2013, 02:26:50 pm
Tim's over on PhotoNet so he's aware of the various issues with Franz if you will. If you really want to know the various rabbit holes we've been down, there's this:

http://photo.net/digital-darkroom-forum/00bjDL

When that got as far as it did, he started this post there (and here and on the ColorSync list):

http://photo.net/digital-darkroom-forum/00bkvN

Point taken, Andrew. The links are quite revealing and one can understand Tim's frustration a little better.

Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 21, 2013, 02:35:26 pm
Andrew,

Observation: your insults and personal attacks are unprofessional, as are Tim's.

Question: since you claim the SoLux bulbs are out of spec, what is the accuracy of your setup and, if you happen to know it, of the other people's setups you refer to? Can't claim a spec isn't met if you don't know the accuracy of the measuring equipment.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 02:54:50 pm
Observation: your insults and personal attacks are unprofessional, as are Tim's.
No personal insults or attacks, both of us don't agree with you and further, you have no means to back up your side of the argument! So to you, that's an insult?

Quote
Question: since you claim the SoLux bulbs are out of spec, what is the accuracy of your setup and, if you happen to know it, of the other people's setups you refer to? Can't claim a spec isn't met if you don't know the accuracy of the measuring equipment.
Here we go, you have to digress and take us farther down a rabbit hole than backup your own data. So here's the deal Franz, three of us, with three different Spectrophotometer's and differing software are all providing very close data points. Robin's $13,000 spectroradiometer correlated very well with his $1500 i1Pro. So just looking at his data, he did exactly what I suggested you NEVER did when you supposedly measured your displays and took at face value the dE report the software provided. He used a reference grade instrument which I'll bet you dollars to doughnuts he has certified by Photo Research on a regular basis. My i1Pro-2 is less than a year old, it has a self calibration process using a white tile so if something where off, it should pop an error. Same with the PR and older i1Pro Spectrophotometer.

But let's present your question back to you: what is the accuracy of your 10 year old Minolta Color Meter you are sure produced a value that got within 50 values of Solux? What instrument and accuracy did Solux use? You must know or how could you accept their data and further tell three of us, our data is either wrong or we did the measurements worng?  I don't expect an answer, I expect more questions to move us into another area to dismiss your poor methodology.

What's good for the goose is good for the gander! Who else besides you have data the correlates with your findings? You've asked in three different forums and you're not hearing the answer you want, so we're either wrong or insulting.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 03:00:36 pm
Can't claim a spec isn't met if you don't know the accuracy of the measuring equipment.
That's exactly what you've done from day one! Care to explain that?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 21, 2013, 03:23:06 pm
Andrew,

That's what I mean by insults and personal attacks (and your previous posts on other forums are chockful of them). Asking what the accuracy is of your measurements is not digression or going down a rabbit hole. It's pretty basic; unless you have the answer, you simply don't know if the SoLux bulbs meet specs or not.

So what about my "piss poor" Minolta color temperature meter? I looked it up and now realize that it has a spec for repeatability, but not for accuracy. Repeatability is specced as 2 mireds, which translates into +/- 44K for the 4700K measurements I did 10 years ago. My apologies for assuming that the number of +/- about 50K that I had in my head was for accuracy, it clearly is not. So, I can't claim my measurements then were within any accuracy, just repeatability.

I don't know what SoLux uses, but I've asked them. And, I would have never claimed their products don't meet specs and publish that data without talking to them first. But that's just me.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 03:41:54 pm
That's what I mean by insults and personal attacks (and your previous posts on other forums are chockful of them). Asking what the accuracy is of your measurements is not digression or going down a rabbit hole. It's pretty basic; unless you have the answer, you simply don't know if the SoLux bulbs meet specs or not.
I answered that and further illustrated that multiple devices corrected rather well. The data provided dismisses your measurements and puts Solux's into question as well. You choose to side with sloppy methodology and a process by Solux you clearly don't know anything about*!

Quote
So what about my "piss poor" Minolta color temperature meter? I looked it up and now realize that it has a spec for repeatability, but not for accuracy.
Ah, so you're putting the same faith into a written spec from Minolta as you do with Solux and that makes it all correct in your mind?

Quote
So, I can't claim my measurements then were within any accuracy, just repeatability.
Again, you're putting the same faith into a written spec about repeatability from Minolta as you do with Solux?

Quote
*I don't know what SoLux uses, but I've asked them. And, I would have never claimed their products don't meet specs and publish that data without talking to them first. But that's just me.
Yet our data is due to incorrect measurements (your exact words): Next, measuring SoLux CCT numbers. There are a lot of wrong ways to measure them and I'm pretty sure the two gentlemen you refer to are doing it wrong.

In actually, you have no idea if they did it wrong did you? Admit it, it's clear.

The more you write, the more easily we can dismiss your POV! Stop while you're way behind here (and at PhotoNet). You have a belief system that's not based on science. You've accepted data you can't check yourself. You've dismissed the work of people who do have the proper equipment and understanding which is pretty shocking! Maybe you can find someone with a old Minolta Color Meter on DP Review who will produce the same meaningless numbers you got and you'll feel better. IF that's insult or an attack, it's based on your inability to accept the scientific method and accept a concept solely on faith. Further you wrote:

Quote
Calibrators have a certain accuracy and when you know that you know what the possible errors in the CCT measurements are. I don't have this information at my fingertips, but for the sake of argument let's say it's +/- 5%. That would translate into +/- 250K for a 5000K calibration. That's not "all over the place" in my book. But since I don't know right now, I'll find out and report back.


You clearly didn't find out nor report back. You made up a very convenient fudge factor to make a point. Very telling! Move on Franz. Your arms are a tad too short to box with dog <g> (grin to impress upon you not to take the licking too personally).
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 03:51:30 pm
This you?

http://www.thereflector.com/people/article_fb08739a-d293-11e0-9ce9-001cc4c03286.html

http://www.amazon.com/The-Obama-Doctrine-Socialism-Corruption/dp/1463641133/ref=sr_1_1?ie=UTF8&qid=1371844309&sr=8-1&keywords=Frans+Waterlander
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 21, 2013, 04:19:13 pm
Andrew,

Just told you that the Minolta didn't have an accuracy spec, so the measurements I took were meaningless. Told you I mistook repeatability for accuracy. The least you could do is gracefully accepting my apology instead of rambling on.

You very well know why I didn't report back on the issue of monitor color temp measurement accuracy, but I'll say it anyway for everybody here to see it: your increasingly hostile attitude, insults and personal attacks on the photo.net forum, which you are now doing here as well.

Back to the issue of accuracy of measuring CCT of SoLux bulbs. The question of how accurate your and the others' measurements are remains unanswered and, I'll repeat it, without that you cant' know whether or not the bulbs are within spec. I again suggest you work directly with SoLux for a resolution.

I've asked SoLux about their measurements and will report on what I learn.

Yes, that's me. Is that an issue for you?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 04:46:29 pm
Just told you that the Minolta didn't have an accuracy spec, so the measurements I took were meaningless.
I told you that a week ago on PhotoNet.

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The least you could do is gracefully accepting my apology instead of rambling on.
When you apologize to Tim and Robin, I'll follow back. Set the example!

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You very well know why I didn't report back on the issue of monitor color temp measurement accuracy, but I'll say it anyway for everybody here to see it: your increasingly hostile attitude, insults and personal attacks on the photo.net forum, which you are now doing here as well.
We've been over this. You don't like being corrected and I spent like 36 posts alone on the original PhotoNet site trying to first help you understand your errors, then go down repeated digressions you yourself designed. Further, how is my so called increasingly hostile attitude, insults and personal attacks stop you from backing up your arguments? Doesn't. Sounds like another excuse.

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Back to the issue of accuracy of measuring CCT of SoLux bulbs. The question of how accurate your and the others' measurements are remains unanswered and, I'll repeat it, without that you cant' know whether or not the bulbs are within spec. I again suggest you work directly with SoLux for a resolution.
And I'll repeat there's no reason to work with Solux, the burden of proof is on their end. At one point it was on your end but you've got no means to do so while often dismissing the work of people who can.

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I've asked SoLux about their measurements and will report on what I learn.
And so if they tell you everything is fine, you'll accept or reject that based on what science? You of all people should know the old saying: Trust but verify!

The same fellow is quoted as say: "Reports that say something hasn't happened are interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns — the ones we don't know we don't know." In your case, based on your writings here and on PhotoNet, I believe you fall into that last camp, you don't know what you don't know. But you sure are tenacious when questioned! Sorry about expecting you to hold up to the peer review.

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Yes, that's me. Is that an issue for you?
No issue, it simply provides transparency about you and gives me further data points on how your mind works.

I'm also somewhat surprised you didn't introduce your new LuLa friends to your new article hosted on the Solux site*, the reason you started all this on PhotoNet. Is that an issue for you?

* http://solux.net/ies_files/Digital%20Darkroom%20Lighting%202013.pdf
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 21, 2013, 05:55:01 pm
Andrew,

I apologize to you, Robin and Tim for saying your measurements must have been wrong, based solely on Intertek ETL Semko's  test report http://www.solux.net/ies_files/IntertekLetter.pdf , SoLux's assurances that their bulbs meet specs and, as it appears now, my erroneous measurements.

However, I can't agree with your statement "And I'll repeat there's no reason to work with Solux, the burden of proof is on their end." Tell us, do you or do you not know the accuracy of your measurements? If you do, then tell us what it is and how the bulbs do or do not meet specs. If you don't, it seems to me, the burden of proof is on you.

I don't want to pick nits, particularly political ones, but trust but verify is from a different person than the one you then quoted next. And once you find out how my mind works, could you please enlighten me as well?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Schewe on June 21, 2013, 06:14:16 pm
Worse, far worse is this is all due to your article, hosted on the Solux site that states we should all be using Solux 5000K bulbs and calibrate our displays to 5000K, after which we'll get a match. Anyone else here on LuLa find that approach doesn't work?

Well, it could work...but it's only one approach...the other approach is to use D65 for the display and the viewing environment. I re-lamped my GTI box with D65 lamps. I use the digital dimmer (has a tiny impact on white balance but not much) to match up the luminance of the display and the lightbox. I get a darn close match when soft proofing. Yes, the ISO spec form proofing calls for D50/5000ºK and yes, that can work. But I've found driving a display down to D50 is less accurate because most displays native white point is close to D65. Depending on your display that can cause banding in the display unless your display has 10bit DACs for internal calibration.

I like the guys at Solux...got to know Phil pretty well because of the Epson Print Academy...but the circumstances surrounding a technical specification needs to be fully explained. Without Solux disclosing EXACTLY how they are making measurements and what tools/software they are using, the specs can't be independently confirmed.

BTW, haven't bothered to read the PhotoNet threads, but I will say that Andrew has exhibited unusual restraints in this thread. Perhaps my skin is a bit thicker than most folks, but I think the OP needs to chill out.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 06:56:38 pm
However, I can't agree with your statement "And I'll repeat there's no reason to work with Solux, the burden of proof is on their end."
It's up to them to verify what they promise. And further to tell us if they don't agree with our findings, where we slipped up (as I tried to do with you and the Minolta). Further, I don't care if a CCT 4700K Solux measures CCT 4500K or 5100K. I told you why (the numbers don't help us anyway, CCT is a range of colors).

The entire reason we got sucked into this issue is due to your article that has a premise:
1. Use Solux 5000K bulbs because they produce 5000K and that's close(est) to daylight. That's not so even IF they measured CCT 5000K.
2. Calibrate your display (no matter the backlight technology) to 5000K. I tried to illustrate that for a visual match, you may need a different value. Again, the numbers don't matter. The correct value to calibrate a display is whatever number produces a match! YMMV. You didn't like that concept despite one of the earliest posts from a user saying doing as you suggested produced a worse result than what he was doing previous to reading your article.

So there are the major disagreements I have. From there, we (I) was sucked into this Solux number rabbit hole, how their numbers (and yours) were correct. I think you're seeing your numbers were probably not correct, mostly due to the incorrect equipment used.

I then found two people who reported on the ColorSync list that:
1. The numbers they measured didn't match what Solux reports.
2. They used different instruments designed to measure spectral color and those measurements were pretty close to agreement. Certainly closer together than what Solux and you reported. But lets' forget what you reported, it's not data we can depend on and use.

You with me so far?

I used a third and differing device but one that reads ambient light and provides spectral data. It's using a newer protocol called XRGA. We can go there but in a nutshell, it is an attempt to better match data from differing devices from differing manufacturers. It is newer than what Robin and Tim were using in 2009. Yet now, for the 3rd time, my data, Tim's data and Robin's data are while not exactly the same (and that's not to be expected), fairly close but far from what Solux reports.

I told you how one can and should gauge accuracy. NOT by reading the spec sheets. I could report what X-rite says both the i1Pro and i1Pro-2 are in terms of actual measurement accuracy. I will not do that because I don't blindly accept these kinds of metrics and neither should you. But Robin used a VERY expensive and VERY precise lab grade spectroradiometer from Photo Research (http://www.photoresearch.com/current/pr655.asp). That's going to be our reference grade instrument to compare the other, far less expensive and far less precise (in terms of specification) devices. It correlated extremely well with a device made by another company that cost a faction of it's cost.

So we have three different parties with four different spectroradiometer devices, all pretty close and all way off from what Solux is reporting. I would kill for a PR-655 but to be honest, even if I had an extra $13K sitting around, I don't need anything like this.

I told you about the analogy of using your foot to measure a room. You assume it's exactly 12 inches. We take a $1 ruler and find out it's 11.3 inches. Your measurements will be incorrect not accurate but by how much and how much accuracy do we need? Now we take a $30 ruler that's supposed to be far more accurate and it states your foot isn't 11.3 but rather 11.298. We then take a measuring device that measures distance from NASA that cost $75,000 and it reports your foot is really 11.198877. If you need to measure that room to buy carpeting, any of the measuring devices expect your foot will do the job. We're not plotting how many mm the earth is to the moon at this moment! One could say, that $1 ruler isn't accurate. And compared to the NASA device, that would be correct.

The PR-665 is far more accurate than the i1Pro. But the i1Pro is fine for the task of measuring the Solux. We are not arguing if the one Solux bulb is 5000.1K or 5000.38590K, or even 4998K. The three of us are using measuring devices that show far, far more than 50K you originally said was 'good enough' to what Solux promises. No one would see the difference.

Quote
Tell us, do you or do you not know the accuracy of your measurements?
I know my measurements and those of the others are within the values that put into question the values Solux says they should be. I do not have a PR-665 or a higher grade unit. I have a lower grade unit (a ColorMunki). I suspect the two will produce results that are well within your 50K fudge factor by a large degree.

The best tests done were those done by Robin that you quickly dismissed because he did use a reference grade lab device to see if it and the lower grade, less expensive, prosumer device correlated and as you saw, (with the 4700K bulb) 127K between the two! Tim's data using the i1Pro was in worst case, 152K from Robin's and in best case, 59K! My one measurement is a difference of 55K and I'm using a different device (i1Pro vs. i1Pro-2). YET in just my example, the differences are 451K from Solux. Now I don't care if Solux CCT 4700K bulbs are 500K from what they state but you sure do. I don't know if the 4700K bulb I buy next year to replace one that burned out will be closer or father off, we haven't even gone into their process control. We haven't take a dozen or more of the same bulb, new out of the box to see how they might match or not match.

So do I think my device and measurements are 'accurate'? Not NASA accurate by far. But far closer than the idea of using that 11.3 inch foot as a 12 inch yardstick if you will. Three independent people produced data that's pretty close. Very close if you factor in just the differences in two identical X-rite devices, the age of the bulbs, how close or far from the illuminate we measured, other factors. I suspect we could correlate our three data sets far closer than they are but this is all a bit 'quick and clean' but again, far, far closer than what Solux reports.

Could all three devices be equally wrong, broken, misused? Or perhaps, the burden of proof is now on Solux, the three independent parties are 'close enough'?

Understood?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 07:04:19 pm
Well, it could work
Absolutely it could but it's not an absolute! That's what I was hoping Franz understood. Then we moved into this silly number game and what Solux claims and he blindly accepts.

Quote
I re-lamped my GTI box with D65 lamps.
Franz will now rip you one for using any kind of Fluorescent bulb. We've been down that path on PhotoNet. That perhaps thousands of print and pre-press shops use them, and people like you and I have to deal with that reality isn't going to wash for Franz.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 21, 2013, 07:32:38 pm
Andrew,

I don't recommend to use Solux 5000K bulbs because they are closest to daylight. If you want to match the color temp of the monitor and lighting, like I do, then you want to select a CCT that is high enough to be acceptable to as many people as possible; even a 5000K monitor is too reddish for some people, but that's the upper limit for SoLux bulbs.

Your main point is that three people measure results that are tightly grouped, but way different from SoLux, ergo, SoLux must be wrong. You apparently don't know how accurate your or the others' equipment is, but you still conclude that SoLux must be wrong. Tight grouping is no substitute for accuracy. As it stands, you cannot claim that SoLux is wrong. And instead of arguing how you are right, in spite of having no accuracy information for your measurements, you could have worked with SoLux, read the test report I referred to, and gotten way more mileage out of our efforts.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 08:05:32 pm
Your main point is that three people measure results that are tightly grouped, but way different from SoLux, ergo, SoLux must be wrong.
I NEVER wrote that anywhere here or on the PhotoNet site. You sir were the one who said we were wrong. Talk about the pot calling the kettle black. Then you crawl in the last post with your tail between your legs with an apology to Robin and Tim and admit as I've suggested from day one, your mythology is shoddy at best! So now you're going to resort to lying and making up shit? Find WHERE I said "Solux is wrong". Nowhere. I said several of us have data which correlates well and doesn't match what Solux is specifying.

Are you so desperate you have to now put words in my mouth? You think the ergo lets you off the hook? You are so hopeless you have once again taken us down the deepest rabbit hole by implying I'm saying the Solux data is wrong and I never said that.

Quote
You apparently don't know how accurate your or the others' equipment is, but you still conclude that SoLux must be wrong.
What didn't you understand, as a so called former electrical engineer that I wrote about the devices and methodology three independent people found that correlate and produce vastly differing values than Solux? English is your 2nd language but man, can't you read posts a few times and attempt to understand what is being said to you? I told you I can provide accuracy data sheets, just like the one's you believe as facts from Solux, for every device we used. Would that make the data correlation three of us found then make you accept that data? I think not.

My efforts have never been about proving Solux wrong because for the 5th or sixth time, I don't care what they say their bulbs are rated at. My efforts from day one was to prove YOU wrong and I've done that so many times, it's funny! You continue to try to wear me down with your digressions, now you've come to the point you have to flat out lie?

How about this: why don't you, as a retired engineer with presumably time on your hands, buy a PR-655, even a i1Pro and test the lights yourself? Then you can present your finding to us and Solux? Why is the burden of proof not acceptable with three of us, one an actual color scientist, yet you, who used some piss poor device and incorrectly, not up to the same standards? You are a piece of work.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 08:15:46 pm
Franz has conveniently ignored a very interesting article I was given prior to release to the CIE. He said he'd get back to us after I arranged a copy for him well over a week ago. It pretty much puts a huge disqualification on this flat earth theories that all displays should be calibrated to "5000K". Here's what I wrote on Photonet:

Quote
I just read a fascinating article by Abhijit Sarkar's recent submission to CIE regarding his work on Standard Observer. I don't think it's out for public consumption yet but in the piece, there's mention of an experiment where users were asked to match via a display using differing back light an image they are viewing in a booth. Two displays were both calibrated using the same product to 5200K. Both displays had quite different SPDs as one used CCFL, the other LED and the spectrum of the two are vastly different. They saw colors on one display being much warmer than the other, the results of the differences of the match they made was between 3 and 13dE (76), the average for all users was a dE of 8! Mostly in the aStar. All viewers were checked for color blindness and scored high in the FM100 hue test.

As I said, like many of the educational material I tried to get Franz to examine, when it puts holes in this ideas, he either dismisses it, ignores it or tells us it's wrong. That's what got us into this silly argument about Solux values in the first place. It worked (to a degree) to sidetrack Franz from answering a piece, about to be published by the CIE, that pokes lots of big fat holes in his paper!

Anyone else want to read Franz's article and comment? It will make for a wild ride towards any topic that doesn't center on this article, the crumb trail is for all to see on PhotoNet but don't go there without copious aspirin!

Franz, you get past page 2? That's all you need to read to see your ideas about color management need a lot of peer review!
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Frans Waterlander on June 21, 2013, 08:37:11 pm
Andrew,

You just said: "So now you're going to resort to lying and making up shit? Find WHERE I said "Solux is wrong". Nowhere. I said several of us have data which correlates well and doesn't match what Solux is specifying." and "by implying I'm saying the Solux data is wrong and I never said that.": So here is what you said in the first post on this thread: "This CCT4700K lamp, inserted within a Solux lamp housing by their design fails as it's off by CCT 451K."

"I told you I can provide accuracy data sheets, just like the one's you believe as facts from Solux, for every device we used. Would that make the data correlation three of us found then make you accept that data?": OK, bring 'em on and explain how your and the others' measurements show that SoLux is wrong, oops, that SoLux fails. "I think not.": Show me SoLux fails in your measurements and then show that your measurements are valid; I have no problem with that whatsoever as I want to resolve this issue and the chips will fall where they may.

Although English is indeed my second language (or is it fourth after Dutch, French and German?), it looks to me like your use of the English language is getting more and more unprofessional, some would even say rude.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 09:17:49 pm
You just said: "So now you're going to resort to lying and making up shit? Find WHERE I said "Solux is wrong". Nowhere. I said several of us have data which correlates well and doesn't match what Solux is specifying." and "by implying I'm saying the Solux data is wrong and I never said that.": So here is what you said in the first post on this thread: "This CCT4700K lamp, inserted within a Solux lamp housing by their design fails as it's off by CCT 451K."

I'm not implying anything. I'm providing you facts which you don't like, I'm providing you measured data from three sources. More of your semantic designed digressions.

Quote
OK, bring 'em on and explain how your and the others' measurements show that SoLux is wrong, oops, that SoLux fails. "I think not.": Show me SoLux fails in your measurements and then show that your measurements are valid; I have no problem with that whatsoever as I want to resolve this issue and the chips will fall where they may.
Here's the data for the three devices. HOW in any way will that change the data we provided? Answer: it will not. Yet the 2nd digression you demand I go through in two posts in the last few hours to keep you from answer the questions presented to you (again, how's that CIE article coming)?

Where's YOUR data, or Solux's data their measurements are correct? Oh I forget, you don't have the means to provide data. Oh I forget, you did provide data which was meaningless. Where's the spec for accuracy of the device you used? Oh that's right, there IS NONE. It doesn't provide spectral data. Only took you a week to get that into your head.

i1Pro Hardware Specifications
SPECTRAL ENGINE
i1® technology with built-in wavelengths check
Spectral analyzer: Holographic diffraction grating with 128-pixel diode array
Spectral Range: 380 - 730 nm
Physical sampling interval: 3.5 nm
Optical resolution: 10 nm
Spectral reporting: 380 ... 730 nm in 10 nm steps
Measurement Frequency in scanning mode: 200 measurements per second

OPTICS
Measurement geometry: 45°/0° ring illumination optics, ISO 13655:2009
Measurement aperture: 4.5 mm (0.18”) diameter (effective measurement aperture during scanning is depending on the patch size and measurement speed)
Illumination Spot Size: 3.5 mm (0.14”)
Light source: Gas filled tungsten (illuminant type A) and UV LED

REFLECTANCE MEASUREMENT
Data Format: Spectral Reflectance [dimensionless]

Measurement Conditions:
UV included - ISO 13655:2009 measurement condition M0
D50 - ISO 13655:2009 measurement condition M1
UV excluded Filter - ISO 13655:2009 measurement condition M2
OBC: Optical Brightener Compensation (OBC) with i1Profiler software
Calibration: Manual on external ceramic white reference
Measurement Background: white, ISO 13655:2009; for measurements on backup board
Minimal Media Thickness: 3 mm (0.12”) on backup board
Minimal Patch Size in Scanning Mode: 7 x 10 mm (0.28” x 0.39”) (Width x Height) with sensor ruler 10 x 10 mm (0.39” x 0.39”) (Width x Height) without sensor ruler
Inter-instrument agreement: 0.4 ∆E94* average, 1.0 ∆E94* max. (deviation from X-Rite manufacturing standard at a temperature of 23ºC (73.4ºF) on 12 BCRA tiles (D50, 2º))
Short-term repeatability: 0.1 ∆E94* on white (D50,2°, mean of 10 measurements every 3 seconds on white)

EMISSIVE MEASUREMENT
Data format: Spectral radiance (mW/nm/m2 /sr); Luminance Y (cd/m2)
Measurement range: 0.2 - 1200 cd/m2 on a typical LCD-Monitor
Short-term repeatability: x,y: +/- 0.002 typical (5000°K, 80 cd/m2)

AMBIENT LIGHT MEASUREMENT
Data Format: spectral irradiance [mW/nm/m2], illuminance [lux]
Type: Cosine-corrected diffuse light measurement head
---------------------
PR-655
Detector    128 detector array
Spectroradiometer Wavelength Range    380 to 780 nm
Optics    Pritchard optical system.
Digital Resolution    16 bits
Spectral Resolution    3.12 nm / pixel
Spectral bandwidth    8 nm (5 nm optional)
Spectral Accuracy    ± 1 nm
Luminance Range    0.2 - 30,000 fL †
Luminance accuracy (Against NIST luminance standard)    ± 2% *
Luminance repeatability    ≤ 1% *
Color Accuracy (for Illuminant A)    ±0.0015 in CIE 1931 x,y *
Measurement Capabilities    Luminance, Illuminance, luminous intensity, chromaticity, correlated color temperature, dominant wavelength.
Measurement Time    3 ms to 6000ms (6 secs)
AutoSync Range    20 to 400 Hz.
Battery    Rechargeable Lithium-Ion. (≥ 12 hours continuous operation)
Weight    3.75 lbs (1.7 kg)
Operating Temperature    34° to 95° F (1° to 35° C)
-------------------
i1Pro
Spectral analyzer: Holographic diffraction grating with 128-pixel diode array
Optical resolution: 10nm
Physical sampling interval: 3.5nm
Spectral data: Range: 380 ... 730 nm in 10nm steps
Measurement aperture: 4.5mm diameter
Interface: USB 1.1
Physical dimensions: Length 151mm, width 66mm, height 67mm (6 x 2.6 x 2.6 inches)
Weight: 185g (6.5oz)
Accessories included: Calibration plate, USB cable, monitor holder, positioning target, scanning ruler, and light measurement head

Measurement geometry: 45°/0° ring illumination optics, DIN 5033
Light source: Gas filled tungsten (Type A)
Physical filters: No or UV cut (Filters not exchangeable)
Inter-instrument agreement: Average DE*94 0.4, max. DE*94 1.0 (Deviation from X-Rite manufacturing standard at 23°C for single measurement mode on 12 BCRA tiles (D50,2°)
Short-term repeatability: DE*94 <= 0.1 (D50,2°), with respect to the mean CIELab value of 10 measurements every 3 seconds on white

Data format: Spectral radiance (mW/nm/m2 /sr); Luminance Y (cd/m2)
Measurement range: 0.2 ... 300 cd/m2
Short-term repeatability: x,y: +/- 0.002 typical (CRT 5000°K, 80 cd/m2)
Type: Cosine-corrected diffuse light measurement head
Diameter: 6.0 mm

Quote
Although English is indeed my second language (or is it fourth after Dutch, French and German?), it looks to me like your use of the English language is getting more and more unprofessional, some would even say rude.
Yes, I'm rude and unprofessional. You've said that several times, I totally agree. In no way does that let you off the hook for your misunderstanding of colorimetry. It doesn't let you off the hook for using poor methodology. It doesn't let you off the hook in ignoring the CIE article that pokes holes in your concepts of display calibration. It doesn’t let you off the hook for saying our data is wrong.

What's the next rabbit hole you want to take us down as an attempt to ignore the mistakes you've made in print?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Schewe on June 21, 2013, 09:20:38 pm
...it looks to me like your use of the English language is getting more and more unprofessional, some would even say rude.

You need to learn American (clue, it ain't English). Andrew has not yet gotten "rude" with you (and I have a passing familiarity with "rude"). When he gets "rude", I'll let you know...really, so far Andrew has been if not pleasant, at least civil.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 21, 2013, 09:22:22 pm
So here is what you said in the first post on this thread: "This CCT4700K lamp, inserted within a Solux lamp housing by their design fails as it's off by CCT 451K."

WRONG again Franz! If you pay a bit more attention, you'll see the "Fail" is what BabelColor shows in it's UI which I posted here and on PhotoNet.

(http://www.digitaldog.net/files/Solux4700K.jpg)

See that red Fail indicator? Just above the Calibrate button?

Of course, totally my fault for not putting a big fat red outline around that part of the UI. OK, next digression.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Tim Lookingbill on June 21, 2013, 10:18:38 pm
Quote
Point taken, Andrew. The links are quite revealing and one can understand Tim's frustration a little better.

Thought Andrew would've gone farther back on those Photo.net links. No problem I'll provide additional links below that show Frans is not a noob.

An every 3 or so year "Pop-In" chit chatter? Yes.

And some of what he says IS insightful and informative as I told him so concerning his updated pdf listing available and affordable IPS monitors which of course he didn't take kindly to what I found online about the "Panel Lottery" going on in the display industry for both TV's and computer displays. He just dismissed my findings as here say. Not very helpful on that one.

These several years old Photo.net threads have some pretty good discussions on the Solux and how color temp appearance affects perception.

This one I started showing why it's not a good idea to calibrate your display to 5000K...

http://photo.net/digital-darkroom-forum/00UbBI

And these have Frans participation...

http://photo.net/digital-darkroom-forum/00ULME

http://photo.net/digital-darkroom-forum/00Rr6Y
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 24, 2013, 09:15:00 am
Franz has conveniently ignored a very interesting article I was given prior to release to the CIE. He said he'd get back to us after I arranged a copy for him well over a week ago. It pretty much puts a huge disqualification on this flat earth theories that all displays should be calibrated to "5000K".

I got an email from the author of the paper I referenced above for publication to the CIE (Commission Internationale de L’Éclairage) The paper is up for public viewing at:

http://www.abhijitsarkar.com/documents/Papers/SarkarBlonde_2013_Colorimetric-observer-categories_CIECentenaryConference.pdf

It dismisses a lot of Franz's idea, the reason he hasn't replied back here after having had access to that paper for 10 days.

It's pretty complex towards the end but the first few pages are fascinating in terms of how differing users reacted to editing an image on differing display technologies using differing backlight technology.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: JRSmit on June 25, 2013, 07:15:46 am
I do. Not just I as you know.

At least two other's from the ColorSync list, one a respected color scientist (Robin Myers who wrote SpectraShop) with a $13,000 spectroradiometer and i1Pro who's data correlated well with mine and others. LuLa audience: This is all known to Franz and I'll copy and paste the same data from the CS list that Franz saw below. When presented this data, Franz said they (and presumably now I) did the measurements wrong. Besides what the marketing department at Solux has placed in their spec sheet, the only other person to get a value that's within what Solux provides is Franz, using a 10 year old Minolta Color meter!

To answer your question Franz, I think you are confusing marketing spec's with science here. It is not up to us to disprove Solux's numbers although we have done so to a degree (at least three independent end users reported the numbers don't jive with the spec's). It's up to Solux to provide an exact process used and for us to then correlate or not. They have not done this! They have the ability to post here, PhotoNet where you started all this, and more appropriately on the ColorSync list. They didn't in 2009 after Robin and other's posted their findings! Why don't you find out what instrument they used, the software used, and the exact testing process used to get their numbers? 

It is you sir that has the devil may care attitude. You don't have the equipment appropriately to measure the SPD and produce the CCT values. You haven't provided any testing methodology Solux used to get their values but you've now posted about this in three forums and when others using at least the correct instrumentation provide values that don't jive with Solux, you have the nerve to tell us we are doing the measurements wrong! You blindly accept the marketing driven spec sheet of a company who's products everyone so far agree's is a good product and who all dismiss the values. It's a shocking attitude from someone who says he's got a bkgnd in the electronics industry. Worse, far worse is this is all due to your article, hosted on the Solux site that states we should all be using Solux 5000K bulbs and calibrate our displays to 5000K, after which we'll get a match. Anyone else here on LuLa find that approach doesn't work?

And

Tim,

Here in The Netherlands the fittings and transofrmers of solux are not available(happily so if reading the issues it gives). None of the normal 12-V halogen transformers of power supplies are actually 12-volt, most of them are 11.5-volt. That is on the supply output, not on the lamp sprocket. So, what i did is use a readilly available electronic power supply that has some regulation of the output voltage in a rang of 11.5- 13.6 volts. Its only drawback is that it cannot provide the peak current at startup of the solux bulbs(or any mr-16 halogen bulb), so i need a 150W power supply to feed 2 50w bulbs, or switch each bulb on to go to 3 bulbs on one supply. It works great and reliable, i can set it to 12-volt on the lamp sprocket.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Tim Lookingbill on June 25, 2013, 08:29:49 pm
Quote
Tim,

Here in The Netherlands the fittings and transofrmers of solux are not available(happily so if reading the issues it gives). None of the normal 12-V halogen transformers of power supplies are actually 12-volt, most of them are 11.5-volt. That is on the supply output, not on the lamp sprocket. So, what i did is use a readilly available electronic power supply that has some regulation of the output voltage in a rang of 11.5- 13.6 volts. Its only drawback is that it cannot provide the peak current at startup of the solux bulbs(or any mr-16 halogen bulb), so i need a 150W power supply to feed 2 50w bulbs, or switch each bulb on to go to 3 bulbs on one supply. It works great and reliable, i can set it to 12-volt on the lamp sprocket.

JR, you really must like those Solux bulbs to go to those lengths setting up a 150W power supply that way. I'm glad it's working out for you. Unfortunately I'm not interested getting into electronics rigging just to drive one halogen bulb.

I'm pretty happy with my GE/Philips T8 flotube arrangement. They're a lot more cool to the touch than the Solux when the Eiko task lamp worked.

It's around 100 degrees right now here in Texas. I'll get by without the Solux. This is all a hobby for me anyway.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 25, 2013, 08:33:56 pm
I'm pretty happy with my GE/Philips T8 flotube arrangement.

If Franz finds out you're using Fluorescent's, you're in big trouble! <g>

Where did that boy go anyway? Working on that rebuttal to the CIE article? Out of digressions? Just when I was starting to have some fun.

Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Tim Lookingbill on June 25, 2013, 08:47:45 pm
If Franz finds out you're using Fluorescent's, you're in big trouble!

I think that was made evident in those several years old Photo.net discussions I linked to, Andrew. I have no trouble at all with my flotubes.

I just wish Frans would add something new to the discussion if he's that knowledgeable about the subject of color science and the lights that affect human perception.

I have to say after reading that CIE pdf more thoroughly, I couldn't find any new information that was helpful or useful in the field.

So I take it that doctorate thesis is based on (1) color analyzer's perception of a 5200K calibrated display's representation of a gray VW automobile image in comparison to a hard copy viewed under a 5000K GTI viewing booth? Where the result of which caused that one color analyzer to edit the image on the display as green to get a match?

I hope the CIE doesn't take that as evidence to change their entire color perception model to accommodate that one person's perception of 5000K rendering of neutral on a display vs a GTI viewing booth.

Or was there something else I missed in that article?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 25, 2013, 08:50:31 pm
Or was there something else I missed in that article?

Nope. It dismissed Franz's idea that despite the backlight of a display and it's SPD, everyone should calibrate to 5000K (or match the display WP value to whatever the print viewing conditions are).
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Tim Lookingbill on June 25, 2013, 09:04:05 pm
So what is the purpose of submitting such an article to CIE (now that I'm relieved that CIE isn't going to change their color perception model on account of it)?

Was the author just technically proving what I tried to illustrate in my years old "Don't Calibrate Your Display To 5000K" Photo.net thread I linked to?
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 25, 2013, 09:12:14 pm
So what is the purpose of submitting such an article to CIE (now that I'm relieved that CIE isn't going to change their color perception model on account of it)?
Was the author just technically proving what I tried to illustrate in my years old "Don't Calibrate Your Display To 5000K" Photo.net thread I linked to?

I couldn't possibly answer those questions but maybe he can:

http://www.abhijitsarkar.com/index.htm

There's contact info at the bottom.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: Tim Lookingbill on June 25, 2013, 10:12:21 pm
Thanks for the link, Andrew. Wonder if he's got the time for a discussion on the subject.

Wonder if 5000K lit content viewed on a 5000K display would act more like the effect of double profiling (warm color temp on top of warm color temp).

My LED HDtv's color temp as to be set so blue (7000-8000K) just to keep broadcast content skin tones from looking greenish brown on a lot of old movies, cable news & HSN studio lit channels. Confusing since I've been told these HDtv sets (and I thought the content as well) was encoded to HD 709 color space at 6500K.

I have to use Warm2 setting on the HDtv to get it to calibrate to 6700K on my Mac Mini using the Xrite CM. If I leave it that way for tv viewing I get the too yellowish greenish brown skin tones. Everything looks dingy and dull.

I wish I could figure out why too blue tv display makes tv content appear more vibrant and/or correct looking. The only guess I can come up with is that tv content isn't 6500K but a much warmer looking 5000K due to the lighting of the original content, but that doesn't answer why it looks correct on my 6500K computer on YouTube feeds of the same content. The content should look dingy and dull as it does calibrating the HDtv to 6700K.

Below is a photo I took of my HDtv I eyeball calibrated using Samsung's Warm1 WB setting (Standard is too blue and registers at around 8000K according to Xrite). In addition I applied a separate tweak to Gain/Offset WB to make content (skin tone) more correct looking and white shirt appear more of an eggshell off white on top of the Warm 1 WB setting. At this setting it'll read around 7400K color temp.

Note the eggshell white shirt has a very blue bias sampling the RGB readouts but yet doesn't look blue at all on my 6500K computer display.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on June 25, 2013, 10:20:35 pm
He seems very open and responsive in the few recent email conversations I've had.
Title: Re: Do SoLux bulbs meet color temp specs?
Post by: digitaldog on July 01, 2013, 12:43:09 pm
From the ColorSync list today (Franz had to ask there as well):

Quote
I remember I measured it with Eye One Display 2 long ago and felt a bit disappointed
(I didn't know what to expect then). It read 4400-4500K, I had got the 4700K ones.
Nipat

Now there's at least a fourth person to conform the same findings!