Pages: 1 [2]   Go Down

Author Topic: Measuring color temperature of a light source  (Read 2485 times)

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 14236
    • http://www.digitaldog.net/
Re: Measuring color temperature of a light source
« Reply #20 on: March 29, 2018, 09:56:55 PM »

How did this thread get so nasty so fast?
Trolls not here to aid the OP. The paper trail is kind of obvious!
Logged
Andrew Rodney
Author “Color Management for Photographers"

Tim Lookingbill

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 2429
Re: Measuring color temperature of a light source
« Reply #21 on: March 29, 2018, 10:02:12 PM »

How did this thread get so nasty so fast?  It started out about some esoteric color management, but will probably get closed. :o  Cue the funeral music:
https://www.youtube.com/watch?v=xt9SN7Y-z-A


Kent in SD

It's not going to get closed. I can assure you. Don't worry about it. Use the information provided and move on. Myself and from what I've seen from others posting have moved on as well.

Andrew Rodney does provide good information and he is knowledgeable in this field, but he does get over zealous when others offer "see something, say something" information or what I call knowledge derived from practical application. Some of us don't like get into color science theory because none of us including Andrew are color scientists. We're all looking for practical application of this technology. Not interested in the politics on which company is the best at applying this technology because there's no way to prove any of it to apply to our workflow.
Logged

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 14236
    • http://www.digitaldog.net/
Re: Measuring color temperature of a light source
« Reply #22 on: March 29, 2018, 10:08:59 PM »

It's not going to get closed. I can assure you. Don't worry about it
Once again, the master of assumption.
You now a moderator here Tim?
Quote
Some of us don't like get into color science theory because none of us including Andrew are color scientists.
Some of us here are actual photographers and understand color science without being color scientists. Some are not; they enter posts without having much understanding of a topic, with an agenda to troll and without any regard to the OP, on a topic about products these people don't understand. Or perhaps even own!
Tim, stating the benefits of the Ignore button will likely continue; it is rude to silence a fool, and cruelty to let him go on.
Logged
Andrew Rodney
Author “Color Management for Photographers"

Tim Lookingbill

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 2429
Re: Measuring color temperature of a light source
« Reply #23 on: March 29, 2018, 10:20:27 PM »

Better get used to reading that kind of input from Andrew by others who post what he doesn't like or agree with. It's a big time waster which is why I'm not going to post in this thread any more.

You could just PM Andrew and you can have him help you on a personal basis?
Logged

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 14236
    • http://www.digitaldog.net/
Re: Measuring color temperature of a light source
« Reply #24 on: March 29, 2018, 10:33:50 PM »

Better get used to reading that kind of input from Andrew by others who post what he doesn't like or agree with. It's a big time waster which is why I'm not going to post in this thread any more.

You could just PM Andrew and you can have him help you on a personal basis?
Either someone here can’t figure out how the ignore button actually works or his “advice” to others, OT as well, is again misinformed.
« Last Edit: March 30, 2018, 09:25:19 AM by andrewrodney »
Logged
Andrew Rodney
Author “Color Management for Photographers"

rxchaos

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 89
Re: Measuring color temperature of a light source
« Reply #25 on: March 30, 2018, 04:03:14 PM »

In i1Profiler set for printer profiling choose the Lighting icon at the bottom, click on the Ambient Light down arrow, and select Measure.  Follow the instructions, I've attached a screen print of a household LED light example.

Richard Southworth

Thank you.  That was easy. I just wanted to be able generate the icc profile using the settings specific for my lightsource.
Logged

Doug Gray

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1381
Re: Measuring color temperature of a light source
« Reply #26 on: March 30, 2018, 04:10:52 PM »

Thank you.  That was easy. I just wanted to be able generate the icc profile using the settings specific for my lightsource.

Make sure you save it after measuring. Then you can just select it from the pulldown custom illuminant menu when you make new profiles for the GTI. No need to measure each time.
Logged

rasworth

  • Full Member
  • ***
  • Offline Offline
  • Posts: 185
Re: Measuring color temperature of a light source
« Reply #27 on: March 30, 2018, 04:28:47 PM »

rxchaos,

Don't be surprised if you get some strange results profiling with "spiky" illuminants such as the one I used in the example.  I tried it with one of my measurement sets - first had a program crash, on the second try the profile generation completed, but using the profile in softproofing revealed ugly color artifacts.  I suspect a relatively smooth illuminant spectrum is required for useful output.

Richard Southworth
Logged

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 14236
    • http://www.digitaldog.net/
Re: Measuring color temperature of a light source
« Reply #28 on: March 30, 2018, 05:22:31 PM »

Make sure you save it after measuring. Then you can just select it from the pulldown custom illuminant menu when you make new profiles for the GTI. No need to measure each time.
Or just drag and drop the ICC profile onto the Lighting Workflow. It, like nearly all settings in all workflows are saved within the profile and can be extracted by drag and drop.
Maybe DP can tell us if the same is true of the product he recommends.
Of course, you want this check box ON:
Logged
Andrew Rodney
Author “Color Management for Photographers"

Doug Gray

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1381
Re: Measuring color temperature of a light source
« Reply #29 on: March 30, 2018, 06:33:42 PM »

rxchaos,

Don't be surprised if you get some strange results profiling with "spiky" illuminants such as the one I used in the example.  I tried it with one of my measurement sets - first had a program crash, on the second try the profile generation completed, but using the profile in softproofing revealed ugly color artifacts.  I suspect a relatively smooth illuminant spectrum is required for useful output.

Richard Southworth

I've posted before some of the strange, profile artifacts I1P sometimes produces. Especially in Perc. Intent. And this was with the default, D50.  I've also had program crashes when using other illuminants, not just measured ones.  In the case of measured ones I wound up tweaking small values in near insignificant portions of the spectrum. Small amounts that would make no more than .1 dE difference anywhere and was able to get it to work.

From this I suspect I1P has a problem with ill conditioned matrixes causing crashes or bad numerical results.  It's not often but it happens every now and then. There are more robust analytic processes but they tend to be slower.
Logged
Pages: 1 [2]   Go Up