Illuminants

Sorry if this have been brought up before, but when I look at photos' EXIF on flickr, I see the following; Viewing Conditions Illuminant Type D50 and Measurement Illuminant D65. Should the numbers match? If so, what do I need to do to make them match? Please, would someone enlighten me.

What calibration device and software did you use on your monitor?

Spyder3Elite 4.0

Well that's where that data is coming from. When you calibrated your monitor you set the temperature to 6,500 Kelvin or D65. The Spyder sensor either detected, or was told, that the viewing environment was mostly 5,000K light.

You don't need to make the number match; the calibration should automatically compensate for the ambient lighting conditions.

I'm just curious... all of my devices are working properly. When I do an internet search, what I find are mathematic equations and charts that intimidate me. Is the viewing environment what the camera sensor thinks that it's looking at as far as white balance is concerned? My in-camera WB setting was "Daylight" which is pretty close to the D50 value.

Well, I'll confess my total ignorance, but I'm interested, because the things I saw when I searched didn't appear to "tie things together".

For example, what would you see if you used a totally un-calibrated system? I'm not so sure that calibration is the "key" here, I saw nothing about it in the stuff I read, but like I said, I plead ignorance!

The "viewing environment" is the room illumination that the calibration puck sees when looking back into the room, if you enabled that feature. It has nothing to do with the camera, any of its settings or the subject illumination.

Elie, I don't want to be argumentative here, but from my reading it appears that the "illuminative values" historically far pre-date our calibration values. They seem to reflect 1) The actual room illumination (your viewing lighting) and then your illumination from your monitor. Both of those are fundamental concerns. The interesting thing is that the two values presented in the Flickr Exif, D50 and D65, are "standard" values that attempt to approximate "daylight", one commonly used in the Americas (D50) and one commonly used in Europe (D65) but seemingly they get mixed up!

So my question remains, I don't have Flickr or a program that "reads" and "displays" these values, what do you get with no calibrator? Maybe nothing, maybe the "standard" values, or maybe one that is just "tweaked" by adjusting your monitor viewing temp but nothing showing what could be considered your "ambient" temp?

I don't know, that's why I'm asking!

Hi Tony,
I think we said the same thing - D50 is the room illumination that approximates sunlight and is the recommended viewing light for judging prints (and is assumed in soft proofing). D65 is the standard for the backlighting on monitors, which don't always achieve it but are generally close. Any monitor that I have calibrated to use its "native" illumination has measured out in the 6300K to 6600K range.
I also have never seen these items in an Exif or understand how or why they got there since the Exif is supposed to relate solely to camera properties, without regard for what might have happened to the file after it exited from the camera. It is like including in the specs sheet for a new car that the driver has blonde hair and the car will be driven on four lane highways.

Heh, well I've seen "metadata" appear in viewers that reflect software "work" (like PS and Lightroom work) but nothing reflecting calibrators, so I think something else is going on here...?

After further research, I agree with these points:

tzalman wrote in post #16317791
• D50 is the room illumination [ScatterCr edit: print viewing booth or gallery display] that approximates sunlight and is the recommended viewing light for judging prints (and is assumed in soft proofing)
• D65 is the standard for the backlighting on monitors
• Exif is supposed to relate solely to camera properties

From what I conclude, the D50 Viewing Conditions Illuminant Type value is important if I choose to display prints in the most flattering light to accurately reflect the colors.