Color Shifting at High Shutter Speed

[Bill Ward]

I was shooting at a 2000/sec and 3000/second shutter speed last week, and noticed an odd pulsing color shift. About every two-three seconds, the color balance would morph to a warmer look, hold for a few seconds, then slide back to normal.

This happened in a manual WB mode. I rebalanced, same issue. I went to autoWB, same issue. Took off shutter speed, problem goes away.

Any ideas why the high shutter rate triggered this, and how to fix it? This was indoors, by the way, with a mix of flourescent and daylight sources.

[Gints Klimanis]

Originally Posted by Bill Ward

Any ideas why the high shutter rate triggered this, and how to fix it? This was indoors, by the way, with a mix of flourescent and daylight sources.

I've seen this problem with my FX1, Z1U and now EX1. I don't have a great explanation for this other than the longer shutter speeds average out the color change over a fluorescent light's cycle. So, it's not just the shutter speed. A video camera isn't shooting a true 30p or 60i frames /second locked to the electrical supply frequency of 60 Hz. This means that the shorter shutter speeds are capturing a tiny time slice of the FL cycle, which isn't color balanced over the entire cycle. So, the solution is to use the pro, flicker free fluorescent lights or skip FLs altogether.

Another issue is to ensure that your white balance process uses at least 1/60 seconds of data. DSLRS can take an incorrect white balance this way. You just have to white balance with a shutter speed of 1/60 or slower. I'm not totally sure this is the case with any or all camcorders, but to be on the safe side, I do it anyway.