by iamlucky13 » Wed Aug 08, 2007 5:14 pm
I think the steam acutally has moved in the picture. It looks streaked. Not to mention, you generally need at least 30 seconds exposure to get a good picture of the Milky Way. The very minor streaking of the stars also suggests this is the case.
I'm guessing the illumination comes from lights at the visitors center behind him. Notice the ground and trees are partially illuminated, too. It's also possible he used a flash or even a flashlight to briefly light up the plume. On a long exposure even subtle details are visible.
There are lens filters you can buy that create diffraction spikes on point light sources, and the brighter the source, the more defined the spikes. This seems most likely because even the moderately bright stars show a little bit of diffraction.
I think the steam acutally has moved in the picture. It looks streaked. Not to mention, you generally need at least 30 seconds exposure to get a good picture of the Milky Way. The very minor streaking of the stars also suggests this is the case.
I'm guessing the illumination comes from lights at the visitors center behind him. Notice the ground and trees are partially illuminated, too. It's also possible he used a flash or even a flashlight to briefly light up the plume. On a long exposure even subtle details are visible.
There are lens filters you can buy that create diffraction spikes on point light sources, and the brighter the source, the more defined the spikes. This seems most likely because even the moderately bright stars show a little bit of diffraction.