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Sunday, March 18, 2012

Song Sparrow, I think

I walked along Battle Creek west of Hermosa this afternoon, practicing with a new lens. I bought a Sigma 400mm mirror lens (short and fat with a big plastic disc in the center of the front glass) for $150 on eBay, and a 2x converter for $25, resulting in 800mm of magnification (roughly 24x if you compare it to binoculars or a scope).

These shots (the sparrow) were from a distance of around 90 feet, give or take 20 feet. 60%-70% of the frame is cropped out. I shot at 1/500-sec. or faster. The lens has a constant aperture of f5.6; the doubler reduces that to f11, so light could be a problem later than 4pm or when the sun goes behind a cloud. These were shot earlier, in bright sunlight or lightly hazed sunlight. The sparrow is in shadow, so I bumped the contrast a little in PhotoShop.

I'm pretty satisfied with the results. I always want more resolution (which usually translates to sharper photos), but this is much better than using a sharper 200mm lens with a doubler (making it 400mm) and then enlarging a smaller portion of the frame. I was using a monopod or freeholding the camera. I lost lots of frames to camera shake. I wonder how much sharper a $2000 600mm lens is, hmmm....

1 comment:

D.E. Bishop said...

Good photos. I love a long lens, though I don't have one now.

The shake with those bigger lenses is tricky. I always tried to prop my elbows against my body. That meant I had to adopt the most horrendous posture. Didn't always work, but holding the lens away from myself, arms free, almost never worked.

Tripods are good, but sometimes they take too long to set up. Monopods are good.