Well- I sought confirmation from several angles and it seems things are straightened out.
I used Mr. Bill's data to cross check results ...
My lowest values were obtained when the complementary color to that indicated by Mr Bill, was set.
According to the comments about RGB and CMY being sort of interchangable, perhaps this is a non-issue.
I just came across an old Macbeth user's manual for a reflection unit - they note that the colored dots on the turret are the same color as the sample to be read, "for convenience." Also, they confirm that the actual filter is the complement - that is, the cyan-dot turret position is used for a cyan test-patch, but it uses a red filter, etc. This is essentially what I said in a previous post.
One might wonder why "for convenience," well, at one time it was common for process control strips (paper process) to have separate cyan, magenta, and yellow test patches. So the color code helps the neophyte take the readings properly. Still, when it's time to plot results on a chart, it's traditional to translate back to red, green, and blue (see Kodak's Z-manuals, for process control, for confirmation of this).
So, just to confirm, even though Macbeth unit has cyan, magenta, and yellow on the turret, it is still taking the readings commonly referred to as red, green, and blue. And it should be acceptable to say it either way, ie, "I just measured the cyan dye density" is the same thing as "I just took a red-filter reading." But if you're talking about process control charts, it's always about the "red plot" (or green, or blue) never cyan.
By the way, I took a close look at your readings. I had thought you could need to use the Macbeth card as your calibration tool - had you done so, then the white patch would necessarily read whatever you made it "calibrate" to. Since your yellow reading (ie, blue-filter) is so high, I presume that you calibrated the machine in another manner, then took readings of the card. IF this is correct, AND IF your white patch truly is yellowish, then everything seems to be normal.
Also, I re-read my chart with another instrument, which can translate into density values for the different status systems. Status E and T both have recognizeable color signatures, which your machine does not show. Therefore, I'm pretty confident that yours is a status A, which is what you want for reading color prints.
My Light is quite yellowish... is this normal?
Are they generally useable till they die?
Or, are they supposed to be used for some % of their entire life?
In my experience, they have a very long life (much longer than a transmission densitometer), then will just go dead. But I don't think there should be a yellowish appearance. You might want to have a look inside, if you're handy with these things.
So hopefully you have a good working machine to play with. I'm off for a long weekend, but will check back here Mon or Tues to see if anything new.
