What's this color cast?

[sekhar]

I'm getting a weird color cast when aiming my camera (6D) directly at a CFL. If I aim to one side, the other side gets the cast; if I aim in center it's all white. Could someone explain this?

 

[KmH]

That's the electricity charge cycling through 60 hertz per second. Alternating current - Wikipedia, the free encyclopedia

Each shutter release is catching the light in a different portion of the cycle.

Strobed lighting is DC - http://en.wikipedia.org/wiki/Direct_Current

 

[sekhar]

Cool, thanks. Didn't realize they change color through the cycle.

 

[KmH]

That's a main reason why fluorescent lighting sucks so bad for doing any kind of photography at shutter speeds shorter than 1 second, or at shorter even fractions or multiples of 60 hz.

 

[bratkinson]

That's a main reason why fluorescent lighting sucks so bad for doing any kind of photography at shutter speeds shorter than 1 second, or at shorter even fractions or multiples of 60 hz.

I've been struggling with non-flash work at church under flourescent lights with oddball color casts from one shot to the next, perhaps 1 second apart. Even using a Whibal card and/or Xrite Color Checker wasn't giving consistent results! So I often used someones' white shirt in a picture to set white balance in Photoshop Elements and made minor tweaks from there if needed. Then the very next shot, same group of people, THAT wb setting was off by a mile! So it was back to the white shirt again.

I had long since forgotten film days where even with the right filters, flourescent shots still came out screwy. I should have known better! I'll have to start using the flash under flourescent to 'fix' the color issues. But then, I have to REMEMBER to do so!

 

[enzodm]

I'll have to start using the flash under flourescent to 'fix' the color issues. But then, I have to REMEMBER to do so!

two light sources with different color temperature might give you even more headache...

 

[amolitor]

The degree of the problem is likely to vary wildly with the exact model of bulb. Lights with more persistant phosphors will provide more consistent light.

 

[480sparky]

Add a dimmer to the equation, and things really get funky.

 

[KmH]

I'll have to start using the flash under flourescent to 'fix' the color issues. But then, I have to REMEMBER to do so!

two light sources with different color temperature might give you even more headache...

Using flash can mitigate that a great deal, particularly if the ambient light light source exposure causing the imbalance and is reduced at a ratio less than the strobed light.