Wednesday, March 5, 2014
Day 52, Learning 52: Eye vs Camera
The human eye is an amazing thing. At the center of it focal area it equals a 52MP camera in terms of resolution (this lessens as it moves to peripheral vision); it has an astounding 24 f stops of dynamic range-- compared the 12-13 stops of a high end DSLR or mid-range medium format camera. It's ISO goes down to 1. It auto white-balances to perfection every time. It's roughly the equivalent of a 50mm lens. And, of course, it naturally captures images in 3D.
The dynamic range, in reality, is actually closer to 12-14 stops. The eye reaches 24 by quickly adjusting. At any given fraction of a second it only spans the lesser range.
When you're photographing them, it's best practice to keep them in the upper 2/3rds of the frame, focus on the nearer eye, and catch-lights (the tiny reflection of your light source) give them the appearance of "life." If the eyes appear dull, there's a Photoshop trick for giving them depth and bringing out the color range. Select just the eyes using with the Quick Select tool or some other; Feather the edge so it's not hard; copy into a new layer; then set the Blend Mode to "Color Dodge." They'll really pop. You can adjust the opacity to reduce the effect, and I sometimes apply a mask and hide the catch light because it sometimes turns too white.