Thursday, May 1, 2014

Healthy Vision - Day 121 #CY365 @ThisIsRobThomas

May's #CY365 theme is about vision. While today's cameras are quite remarkable at capturing what we see, their "vision" is not at all equal to our own eyes. Our eyes eye can actually perceive a greater dynamic range than is ordinarily possible with a camera. If we were to consider situations where our pupil opens and closes for varying light, our eyes can see over a range of nearly 24 f-stops while 8-12 f-stops is generally all one can expect from a digital camera. This is most evident in low light photography especially when bright highlights are present, such as a stage performance.

Tonight Cindy and I went to see Rob Thomas at the Durham Performing Arts Center. It was an intimate performance with just two musicians joining Rob Thomas on stage. The overall lighting was low but there was always a spotlight on the star. Even with spot metering enabled, my camera struggled to get the low light background exposed, resulting in an sharply overexposed star. Manual exposure or severe exposure composition is the only way to capture the scene and avoid blown-out highlights. Since the camera can only capture a limited dynamic range, much of the scene is underexposed. So every picture is a trade off, while our eyes make the adjustments consistently and our brains composite the image so we see much more. And yes, the show was amazing. Canon G15, 1/80 sec @ f/2.8, ISO 1600.

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