Thursday, February 5, 2009

Beach, Sunrise

Still at Limantour. Back at the beach, the sun just making an appearance, the camera hand-held. I took this photo at the 12mm (24mm equivalent) position. I must say, the horizon line looks a little strange. Not straight, of course. But not nicely curved either. I think that this is what Wrotniak was referring to in his review of the 12-60 Olympus zoom lens:
Note how the straight edge has been distorted into a snake-like shape; this is a rare case where the first-order (really: quadratic) distortion has been quite well corrected at the expense of higher-order terms. I bet, a result of aspheric lens surfaces.
We may say, then, that at 12 mm the distortion is of mostly barrel type, very soon turning into pincushion; all the time well under control. While a set of prime lenses could deliver better, it would not be so easy in a 5× zoom, starting at a wide angle like this. I consider this a very good performance; for comparison, the Leica Vario-Elmar 14-50 mm F/3.8-5.6 shows about twice as much barrel distortion at 14 mm than this lens at 12 mm.
Got that?
Photo: Limantour Beach—Point Reyes, 2009

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