Do SoLux bulbs meet color temp specs?

Discussion in 'Digital Darkroom' started by frans_waterlander, Jun 19, 2013.

  1. 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 your tested out of spec, did you work with Phillip Bradfield or Kevin McGuire at SoLux to resolve the issue and what was the result?
     
  2. My result is that Phillip and Kevin won't provide me a reliable task lamp whose 120v>12v power brick converter won't fail after 40 hours of use so I can operate my one 4700K Solux bulb. It's been sitting in my junk drawer for about 2 years now.
    I'ld say that's a more important issue over your hair splitting over CCT accuracy.
    I'ld really like Phillip and Kevin to hook up a precision "anger and derision" analyzer to check my level of "pisstitude" within a micro-miff.
     
  3. Thanks Tim, that was very helpful.
     
  4. Actually that mirrors my experience too Tim. The lamp failed and the connection melted after a couple of days. Spare bulb was taking up space in a drawer someplace.
     
  5. Thanks Tim, that was very helpful.​
    Not to me it wasn't.
    The only help I and probably Barry and Ellis Vener want is for Phillip and Kevin to give us a replacement task lamp with a lifetime warranty so we can use their beautiful light bulb.
     
  6. Completely agree with Barry and Tim. I've had nothing but trouble with their lights. The bulbs last about a second and/or the actual light dies. I gave up and now use a daylight balanced fluorescent which works just fine, is cheap and lasts for ever.
     
  7. My experience is that the Solux bulbs are great, but their fixtures are crap. I had to send all the fixtures I got from them back. But as long as you use the bulbs in a decent fixture (eg Halo), they perform admirably.
    I've actually got nine Solux bulbs around the house, six in the kitchen. Color is great -- canned sunlight, perfectly smooth fields, and all the six bulbs in the kitchen continue to match over time. So if they are drifting, they are all drifting in the same direction.
     
  8. As promised in last thread on the subject:
    Solux CCT4700K bulbs, measured using XRGA protocol within BableColor CT&A using i1Pro-2 Spectrophotometer. OFF 451K.
    [​IMG]
     
  9. Andrew,
    Have you worked with Phillip Bradfield or Kevin McGuire at SoLux to resolve the issue and what was the result?
     
  10. Have you worked with Phillip Bradfield or Kevin McGuire at SoLux to resolve the issue and what was the result?​
    There's nothing to resolve! My data matches what multiple other's expect perhaps you and Solux have found. It's up to them to prove we are wrong, including Danny Pascale and his fine software above. Further, we've been down this path about the numbers being pretty meaningless since they are correlated and the results here are expected. The only problem is those who misunderstand colorimetry, or use the incorrect devices to measure color, or those that expect spot on perfect values. The bulbs ARE wonderful! The spectrum is lovely. Get past this notion that they should have some value that matches a number printed on the box.
    There is only one device that can produce D50, it is 93 million miles from here!
    IF you had the proper tools to measure the bulbs, if you had the same instrument as I do, using or another using the new XGRA standard, our results would be practically identical using the same bulb in the same housing.
     
  11. As I suggested earlier, take up the subject directly with SoLux, as they can best address the issue. I'm not their spokesperson or have the best possible information to address this issue.
     
  12. As I suggested earlier, take up the subject directly with SoLux, as they can best address the issue.​
    Again, there is no issue to take up. The numbers don't have to match. YMMV. The number will likely also change over the life of the bulb. If you didn't put such credence in those values, like the rest of us, you'd ignore the numbers printed on the box. You'd buy the bulbs because they are the best in terms of viewing images with a non spiky spectrum, you'd set whatever value in the display calibration software that produces a match and ignore that the two are different.
    You want actual daylight? Go outside. And again, who cares what the numbers are? Even D50 is a group of color values taken with expensive Spectrophotometer's, all over the patent and averaged, massaged if you will to produce a standard description of an illuminant**.
    You ever hear of the Standard Observer? It wasn't just one super human guy with perfect vision.
    **The series of D-illuminants was adopted by the CIE in 1971 based on 622
    measurements from the early 1960s: 249 at Rochester, NY (Kodak); 274 at
    Enfield, England (Thorn Electrical Industries); and 99 at Ottawa, Canada
    (National Research Council). Each of these labs contributed spectral
    measurements taken with different kinds of instruments measuring at
    different spectral intervals over slightly different ranges.
     
  13. Since we're on the subject of color perception affected by white balance I noticed my Samsung HDtv I just got several weeks ago looks more neutral when it's color balanced with a slightly bluish bias over my LG27's 6500K color temp.
    The Samsung calibrated off my Mac Mini has to be set to Warm2 WB just to get a 6700K color temp reading according to Xrite Colormunki Display calibration. Viewing programs from 7 feet away on the Samsung in my living room left in Warm2 setting makes colors dingy and whites/grays NOT neutral looking.
    It appears distance and its accompanying surround effect play a big role in color perception because sitting about a foot and a half from my LG27" looks neutral at 6500K calibration.
    Maybe I should've participated in that CIE Standard Observer color perception test.
     
  14. I'm not their spokesperson or have the best possible information to address this issue.​
    The most accurate statement you've made thus far!
     
  15. Maybe I should've participated in that CIE Standard Observer color perception test.​
    In case you missed the other post, start by reading this (at least the first few pages):
    http://www.abhijitsarkar.com/documents/Papers/SarkarBlonde_2013_Colorimetric-observer-categories_CIECentenaryConference.pdf
     
  16. Thanks, Andrew.
    Wow! that is a very comprehensive study and analysis on human color perception...AND THEY INCLUDED A PHOTO!
    Just one?! Come on!
    The green VW Jetta image was the result a contributor over on a 2009 AVSforum thread I read several days ago was complaining about when they paid a calibration technician $400 to calibrate their very expensive HDtv. All the experts were telling the guy that's what it was suppose to look like for all sorts of reasons I now can't recall.
    I think if their is now a contention on whether to side on red or green neutrality I'ld have to say I prefer the red. Green just makes skin tones look like crap without a matrice based profile to correct for it. I don't know if HDtv includes a color management matrice based implementation in expensive calibrations like that but still I REALLY don't like the look of green permeating throughout my display.
     
  17. I love SoLux bulbs but their transformers are crap. I have a whole set of their work lights that are in a junk case in my attic
    because of the transformer issue. Bradfeild is not interested in dealing with the issue with me.

    The opinion about the quality of the transformer is that of a very good electronics repair shop up the street from me.

    On the other hand everyone I know who uses their bulbs in tracklight mounts loves them and they stay trouble free.

    For judging print accuracy and quality I now use a GTi Soft-View D5000 viewing station and also diffuse daylight.
     
  18. For judging print accuracy and quality I now use a GTi Soft-View D5000 viewing station​
    And Franz didn't rip you a new one for using Fluorescent's? Looks like he's left here with his tail between his legs. Finally. I was so wanting him to explain that CIE article I had sent to him and which he promised to comment on.
    FWIW, I too use the GTI booth (I tried to explain to Franz I sometimes have to work with others using the same product). I was just on site last week at a huge print shop evaluating output from their presses and sure enough, multiple GTI's all over the joint. They run cool. The tubes last a long time. Solux bulbs are lovely but not prefect. What is pretty darn close to prefect is daylight as you point out.
     
  19. For judging print accuracy and quality I now use a GTi Soft-View D5000 viewing station​
    Despite Franz's hatred of Fluorescent booth's, and since he asked I measure my GTI booth, here's the report (passes brightness and CCT with flying colors). Note it does fail for MI or Metamerism Index (far right area) due to the spectrum. According to the BableColor manual:
    ISO 23603 / CIE S 012/E : Standard method of assessing the spectral quality of daylight simulators for visual appraisal and measurement of colour
    [​IMG]
     
  20. I'd like to set the record straight​
    Been set straight based on all the posts here, on LuLa and the ColorSync list (plus based on your disappearance), the answer is NO they (Solux) don't met the spec's. The GTI bulbs do.
     

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