s*****t
发帖数: 1994 | 1 11 Hour Star Trails
Credit & Copyright: Josch Hambsch
Explanation: Fix your camera to a tripod, lock the shutter open, and you can
make an image of star trails - graceful concentric arcs traced by the stars
as planet Earth rotates on its axis. Of course, the length of the star
trails will depend on the exposure time. While exposures lasting just five
minutes produce a significant arc, in about 12 hours a given star would
trace out half a circle. But in any long exposure, the background glow from | g****e
发帖数: 612 | 2 hehe,真牛呀
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【在 s*****t 的大作中提到】
: 11 Hour Star Trails
: Credit & Copyright: Josch Hambsch
: Explanation: Fix your camera to a tripod, lock the shutter open, and you can
: make an image of star trails - graceful concentric arcs traced by the stars
: as planet Earth rotates on its axis. Of course, the length of the star
: trails will depend on the exposure time. While exposures lasting just five
: minutes produce a significant arc, in about 12 hours a given star would
: trace out half a circle. But in any long exposure, the background glow from
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