mired shifts

From: Kyja Kristjansson (email suppressed)
Date: Fri Mar 16 2007 - 17:41:51 PDT

hi hi,

I am wondering if somebody can clarify an exact formula for mired shifts in
color temp. I understand how to calculate mireds from the Kelvin value
(1,000,000/K), but I am confused about mired shifts. I came across a source
that states the following:

"subtract the mired value of the desired color from that of the source"

Is that right? Am I reading it incorrectly? (source - desired)??

Because then the source goes on to give the following example:
Source = 5000K or 200mireds. Desired = 3200K or 312mireds...
312 (desired) -200 (source) = 112 mireds, which would be an 85 orange

I found another formula that gives the following:

-[(Mired Value of Source Light) - (Mired Value of Desired Light)]

Which would make quote above accurate, right?

or is it simply:

(Mired Value of Desired Light) - (Mired Value of Source Light)

This should be fairly straight forward... and I'm quite sure that at this
point I'm making it more difficult than it needs to be. Any clarification
would be MUCH appreciated.


Kyja Kristjansson-Nelson
Assistant Professor, Film
Communication Studies, Film Studies & Theatre Arts Dept.
Minnesota State University Moorhead
1104  7th Avenue South
Moorhead, MN, 56563
email suppressed
For info on FrameWorks, contact Pip Chodorov at <email suppressed>.