Originally posted by K1N8 Just curious, does any other vendor display kelvin values in camera?
Yes the Sony seems to, as shown in the video above that I linked.
Originally posted by photoptimist Color temperature is a one-axis color balancing system that only works with some light sources.
MWB is a two axis color balancing system -- adjusting the color on both a blue-amber axis and a magenta-cyan axis. Thus Pentax doesn't give the temperature of MWB because it would be inaccurate.
Originally posted by stevebrot Yes, this is true. Doing manual WB actually generates correction factors that are not readily or reliably back-calculated to Kelvin degrees.
Steve
Wait up tho... I get the whole 'approximation' and all that, but the Sony camera seen in the video I linked above seems to have no problem to giving a Kelvin approximation for MWB, and I'm certain when we take that RAW file snapped of a scene with MWB then LR will display the WB temp used at the time the shot was taken (after calibration), so really... from my perspective this is a cop out by Pentax. You can find the values of Kelvins for the presets for WB in a camera (Daylight, Tungsten etc), and of course we get to manually dial it in, but for some reason using a MWB that info is just hidden?! I really have to stop the shoot, eject the SD card from the camera, copy image across to PC, open the file in LR, see what WB temp it actually is... put SD card back in camera and then select an approximate gel to use for my flash... LOL! If you ask me it's another 'lets forget about flash stuff entirely' Pentax issue.
Originally posted by AstroDave If they do, they are probably incorrect, unless the light source is a "black body," as noted by photoptimist and Steve above.
Look at this frame from the Wikipedia article on black-body radiation (
Black-body radiation - Wikipedia)
Black-body radiation - Wikipedia
Note the "planckian locus." It's just a line through color space, whereas a light source might well fall anywhere in there (such as a non-"warm" LED that would have relatively a lot more blue emission).
It might be inaccurate, but it might be in the ball park close enough to allow someone to select an approximate gel to use for the scene (gels after all are approximation stuff themselves. You might not have a 3000k gel but you have a 3200k gel so you use that etc.