Chris Peterson wrote:
Remo wrote:I too was curious about the impossible smoke stream -- and I think you folks have solved it -- except that given the straps opaqueness near the station and the rapid narrowing of the strap until it appears both constant width and transparent at the extremity, I suspect that it is more than just the strap is out of focus, but also that it has some sort of movement (oscillation) over the time period of the photo.
It was a 1/500 second exposure. I doubt that there was any significant motion blur. The impression of transparency is probably because the strap is so close to the lens that it doesn't fully block more distant rays. Put an opaque strip (like a piece of tape) a few inches from a camera lens that has a larger aperture than the strip width, and you'll get this effect.
I understand optics. And part of my observation was based on the assumption of a slower shutter speed. Nonetheless, what was the f-stop? (Can't find either the speed, the f-stop or the lens anywhere).
Also, when compared to photo 2, the amount of blur of the strap is far greater in picture 1 when compared to the amount of blur of the background in picture 2 when the blur should be reciprocal. Also, the rapid opaque taper combined with the constant width and transparency at the extreme doesn't correlate. One would expect a sharper image from an object at the extreme, when based on the taper, the extreme was at least 3x farther away.
Notwithstanding, you might be correct; however, at present your explanation does not fully explains the phenomena.