Saturday, March 6, 2010

Strobe Colour Temperature and Blue

Saw Alex Mustard's article "Strobes and Water Colour" after I asked the question "Warming Filter On Strobe, What does this do to the blues?" in the wetpixel forum.

Quote Alex Mustard:
"The root of this phenomenon is that the various underwater strobes on sale produce light at different colour temperatures and digital cameras have adjustable white balance that reacts to this.

When you take a picture illuminated by 5500 K or 4300 K light you will need a white balance close to this value to render neutral colours. This setting is applied to the whole image. In the real world this means that both strobe lit and non-strobe lit areas are affected, and therefore strobe choice can affect the background water colour."

So off I went to re-process some of my raw photos to see the effects for myself. I used twin Ikelite Substrobe DS125 and DS160, both balanced for 4800K (didn't know this until I started considering Alex's article). Camera used was Fujifilm S2Pro, lens Tokina AT-X 107 AF DX Fisheye AF 10-17mm f/3.5-4.5. Camera settings: ISO100, Manual Exposure 1/60s f/8, lens at 11mm, Strobe set on TTL.

See conversions of raw photos at different colour temperature below:



Interesting although subtle shift in the background blue. Which is better?

My take right now is the one given a white balance of 4800K is the "correct" foreground colour, while the blue in the background is probably that tiny bit more saturated than the actual scene. But then again the blue is the background is a function of what combination of shutter speed and aperture I use, so the "actual" blue is again never quite well defined.

I'd go for the 4800K shot.

No comments:

Post a Comment