What Illumination choice??

[George in Georgia]

I'm approaching my third refill on my Pro 100 using Precision Colors inks, so its about time to try some of PC's profiles. My question is which of the illumination choices, Standard D50, Tungsten, or Florescent would be a reasonable choice for general use? I find the Florescent option puzzling, since there are a variety of florescent tubes - coo white, warm white, etc.

I'm making less mess of myself and my work surface with each refill, so I won't have multicolored hands too much longer.

 

[The Hat]

I don’t know about your prints or profile but I reckon your hands will look much better with the warm white ..

 

[3dogs]

x 10

 

[Lucas28]

The warmth of the light is measured in Kelvin.

Tungsten: color temperature is 2900 Kelvin. The light is yellowish. Halogen light is a bit cooler, 3200 K.

Standard D50: color temperature is 5000 K. This is the normal daylight outdoor. The light is supposed to be white, but looks bluish compared to tungsten.

Florescent: color temperature is 3900 K but differs with the brand of the tube. As you stated there is a variety of florescent tubes, but most common is the 3900 K variant. The light is between tungsten and daylight, but there is higher green portion in this light. Better not use this option.

The standard D50 is the most used setting and I assume it's preferable to watch your proof prints. Watch them by the window for the best light.

 

[Grandad35]

I've never seen where the "White balance" is involved with a printer profile. Assuming that you are shooting jpeg images, the white balance options (as explained by @Lukas28) must be set in the camera when you take the shot. Unless you are shooting RAW images, I don't know of a way to adjust the white balance after the image is taken. Google for "white balance" - there are lots of links that discuss the subject. Are you getting the "rendering intents" (which must be set with a profile) confused with the white balance?

 

[George in Georgia]

No, I don't think I'm confused about white balance. I went to RAW almost exclusively shortly after getting my first DSLR, a Pentax K 10, enjoying the extra "latitude" afforded.. No, I'm referring to the three different ICC profiles that PC furnishes for each paper, one for D50, one for tungsten illumination, one for fluorescent illumination.

 

[Grandad35]

No, I don't think I'm confused about white balance. I went to RAW almost exclusively shortly after getting my first DSLR, a Pentax K 10, enjoying the extra "latitude" afforded.. No, I'm referring to the three different ICC profiles that PC furnishes for each paper, one for D50, one for tungsten illumination, one for fluorescent illumination.

@mikling,

I have never seen profiles tuned to the viewing illumination, and I wasn't aware that you were offering such profiles. It has always been my understanding that prints must be viewed under standard lighting conditions to judge the color.

My I1 spectro illuminates its targets with its built-in light source, and there is no way to illuminate the test charts with any other light source to generate a profile tuned to different lighting. Do you have a software package that tweaks a profile to simulate other light sources, or does your spectro have a feature that allows you to adjust the temperature of its internal light source? I can see that profiling software could tweak the colors measured by the spectro to simulate the color shift that might be expected with different lighting, but (as George stated), how would you know the spectrum of the user's lighting and how would you correct for metamerism?

 

[mikling]

Yes, the most normally used file is the D50 as the standard. If you happen to be in a situation where the light source is nowehere close to daylight, you can try and see if the other illumination choices may help.
The other illumination choices are industry standard BUT as correctly noted, might not be exactly what is encountered but might be better than a D50 choice in that particular situation.
The proper way to go about this is to use the spectro to measure the illumination characteristic and note the data. Having this data, the profile will then use this during the creation of the profile.
Further to this is to even measure the reflectance characteristics of this paper in that particular illumination situation and then incorporate that data as well so that the effect of OBA can then be incorporated into the calculations.
As noted the last two options require measurements in specific situations. One may look at this this way if we know that D50 is way way out, maybe a tungsten will bring it closer though we know it is still not correct.
Many many people view prints in non standard conditions or are not displayed in standard conditions so though the print is perfect in a light box it may look off in a different illumination situations.

I believe Colorbyte RIPS also provide for differing illumination scenarios as well.
http://www.colorbytesoftware.com/Ver9/theBest.shtml

"Light is not white. It comes in many shades, from the cool-white of D5000 to the warm-white of tungsten. Profiling to the wrong light source is the number one cause of those undesirable color shifts you may have noticed in your prints. Everyone else profiles for only one color of white — D5000 — the old, traditional lightbox standard. Imageprint includes 5 colors of white for every paper we profile, PLUS grayscale for the black and white enthusiast"

Well, I'm giving three for free and maybe those other two can help when the D50 doesn't cut it.

While we're at this, let's have some fun as well. Choose the other ones and see what results you get by comparing in the same light source.

XRite iProfile now does something similar as well. However, what they do is that they ask you do as an intermediate step is to print out some patches and compare it to references they have printed out in the given illumination situation. Choose the closest match by eye and note the choice. They then incorporate this choice into the final profile. So in effect, they obtain both the illumination spec and the oba in the comparison in the chosen light. So in the end you use your own eyes as an IT8! They use grey as we are very sensitive to those.

Argyll separates these two aspects into two measurable sets of data. That way apparently, they can calculate the correct compensation. How well this works in practice, I have not had time to delve fully into it as yet.

Argyll CMS is very powerful.

 

[3dogs]

Match with whatever light source you have in the place where you process. So if you process during the day with no additional light use the daylight option.

 

[Emulator]

Might I draw your attention to RogerB's contribution in post #1 of http://www.printerknowledge.com/thr...p-argyll-cms-profiling-on-your-computer.8570/

"This next batch file has been contributed by RogerB. (ArgProf#2.txt)
It has two additions:
a) An option to specify a different illuminant when generating the profile. If you use dye inks and you know that your prints will be viewed under tungsten illumination then selecting "A" as the illuminant should get rid of any red cast in B&W prints........................."