paulgarstki
New member
Anyone know what color temperature is assumed for the flourescent color matrix? Flouresc. lights have several different "standard" temperatures, like cool white, warm white, daylight, etc.
--Paul
--Paul
flourescent color balance?
- Thread starter paulgarstki
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Barry_Green
Moderator
Re: flourescent color balance?
I don't believe the fluorescent matrix has anything to do with color temperature, it would work with daylight or tungsten or custom color temperatures. The matrix is how it rearranges colors, but you have to have the white balance set properly for it to know what the starting colors are.
I don't believe the fluorescent matrix has anything to do with color temperature, it would work with daylight or tungsten or custom color temperatures. The matrix is how it rearranges colors, but you have to have the white balance set properly for it to know what the starting colors are.
paulgarstki
New member
Re: flourescent color balance?
Okay, color temperature is an elusive concept when dealing with flourescents. I probably should have written, "which PHOSPHOR is assumed" for the flourescent matrix.
Adam Wilt claims "Fluorescent [matrix] boosts the reds compared to normal, giving richer flesh tones under red-deficient fluorescent lighting." John Beale, in the notes to his DVX100A comparison charts, writes, "In the matrix settings, the "fluorescent" setting appears to mostly affect the red and yellow colors making them more saturated relative to the normal setting."
Such compensation would seem to be pointless unless you had a specific deficiency -- meaning a specific or at least typical phosphor -- in mind, no? White balance can only take you so far before the colors get skewed at the more extreme ends of the curves. As Walt Graff said (regarding using white balance to compensate for the green spike characteristic of some flourescent phosphors), "That could work well too in some instances but the unevenness of color spectrum might make other colors look slightly different."
So that's my point. I know I could white balance in flourescent light -- but I could do that with any matrix. If I knew what environment the FLOUR matrix was designed for, I have a better starting point. (And oddly, the red-yellow region that Wilt and Beale identify would seem to compensate for blue-cyan, instead of the typically flourescent green...)
I guess I'll have to stoop to actually doing tests...
Okay, color temperature is an elusive concept when dealing with flourescents. I probably should have written, "which PHOSPHOR is assumed" for the flourescent matrix.
Adam Wilt claims "Fluorescent [matrix] boosts the reds compared to normal, giving richer flesh tones under red-deficient fluorescent lighting." John Beale, in the notes to his DVX100A comparison charts, writes, "In the matrix settings, the "fluorescent" setting appears to mostly affect the red and yellow colors making them more saturated relative to the normal setting."
Such compensation would seem to be pointless unless you had a specific deficiency -- meaning a specific or at least typical phosphor -- in mind, no? White balance can only take you so far before the colors get skewed at the more extreme ends of the curves. As Walt Graff said (regarding using white balance to compensate for the green spike characteristic of some flourescent phosphors), "That could work well too in some instances but the unevenness of color spectrum might make other colors look slightly different."
So that's my point. I know I could white balance in flourescent light -- but I could do that with any matrix. If I knew what environment the FLOUR matrix was designed for, I have a better starting point. (And oddly, the red-yellow region that Wilt and Beale identify would seem to compensate for blue-cyan, instead of the typically flourescent green...)
I guess I'll have to stoop to actually doing tests...
Barry_Green
Moderator
Re: flourescent color balance?
Testing is of course the only solution. But it is still my understanding that the FLUOR matrix is not related to color temperature, but to compensate for the deficiencies in the color spectrum. It should work equally well whether you are shooting under "warm white" lights (2700k or so) or "cool white" (6500k or so).
Color Meters report readings on two different axes: red/blue (which is compensated for by white balancing, or using #80-series filters) and also on the purple/green axis, which is where you'll find the spectrum problems in fluorescents. You'll get a CC reading of +21M or so on your color meter, showing that you need to add 21 units of magenta to the light source, which is probably around a half or full minusgreen.
So white balance can try to compensate for the deficiencies, but I believe the FLUO matrix is ther to "go the extra mile", to compensate for what white balance can't.
Testing is of course the only solution. But it is still my understanding that the FLUOR matrix is not related to color temperature, but to compensate for the deficiencies in the color spectrum. It should work equally well whether you are shooting under "warm white" lights (2700k or so) or "cool white" (6500k or so).
Color Meters report readings on two different axes: red/blue (which is compensated for by white balancing, or using #80-series filters) and also on the purple/green axis, which is where you'll find the spectrum problems in fluorescents. You'll get a CC reading of +21M or so on your color meter, showing that you need to add 21 units of magenta to the light source, which is probably around a half or full minusgreen.
So white balance can try to compensate for the deficiencies, but I believe the FLUO matrix is ther to "go the extra mile", to compensate for what white balance can't.
paulgarstki
New member
Re: flourescent color balance?
Thanks, I think you're right. My guess is that the matrix compensates for the blue spike below around 450 nm. My past as a filmmaker makes me want to see the curves for everything before I start...
Thanks, I think you're right. My guess is that the matrix compensates for the blue spike below around 450 nm. My past as a filmmaker makes me want to see the curves for everything before I start...
Barry_Green
Moderator
Re: flourescent color balance?
Don't take my word for it, that's just the way I understand it, but that doesn't make it right. Testing is the only way to know.
Don't take my word for it, that's just the way I understand it, but that doesn't make it right. Testing is the only way to know.
Re: flourescent color balance?
These warm-card things that are out now...a special add-on pack(for about $25-30)offers a white-balance card that has what might be 1/4 or 1/2 green gel overlayed on top of the white card. A white balance with this greenish laminated white card gives some pleasing results under any flourescent fixtures...I believe Barry's got the key here: color temperature means virtually nothing with lights that are not full spectrum. The very green flours have a color compensation(CC) shift that requires white balance help. A nice test might be the DVX flour setting vs. a white balance through 1/4 or 1/2 plus green...
These warm-card things that are out now...a special add-on pack(for about $25-30)offers a white-balance card that has what might be 1/4 or 1/2 green gel overlayed on top of the white card. A white balance with this greenish laminated white card gives some pleasing results under any flourescent fixtures...I believe Barry's got the key here: color temperature means virtually nothing with lights that are not full spectrum. The very green flours have a color compensation(CC) shift that requires white balance help. A nice test might be the DVX flour setting vs. a white balance through 1/4 or 1/2 plus green...