by Nitpicker » Tue Jan 26, 2016 7:52 am
Ahem, yes, I like to imagine that I would have spotted an ISS sequence transiting M101, as a fake.
So, I can well accept that an exposure time of 0.001 seconds, or less, is required to freeze the image of the ISS at this scale, even when low on the horizon and travelling with a reduced angular speed relative to the camera. (And note that the video frame rate does not need to relate to the exposure time, which can be much less than the interval between frames.)
But I imagine that with a big/fast enough scope, and a good enough camera, Saturn could still be exposed to a level comparable to the now infamous faked Saturn (which was presumably recorded around the time of its most recent opposition, based on the lack of ring shadow, as has already been mentioned). Is anyone capable of estimating the kind of scope and camera that might be required to expose Saturn nicely in 0.001 seconds?
I imagine that if one had the gear to expose Saturn nicely in 0.001 seconds, and if the highly variable magnitude of the transiting ISS just happened to be in the same ball park as the magnitude of Saturn, then there is no reason to suppose the task impossible.
I'll note that the other (real) video of the ISS transiting Saturn, posted here recently by Astrofan, appears to have been recorded with quite a small scope. It is a great video, though Saturn is a little underexposed.
Ahem, yes, I like to imagine that I would have spotted an ISS sequence transiting M101, as a fake. :oops:
So, I can well accept that an exposure time of 0.001 seconds, or less, is required to freeze the image of the ISS at this scale, even when low on the horizon and travelling with a reduced angular speed relative to the camera. (And note that the video frame rate does not need to relate to the exposure time, which can be much less than the interval between frames.)
But I imagine that with a big/fast enough scope, and a good enough camera, Saturn could still be exposed to a level comparable to the now infamous faked Saturn (which was presumably recorded around the time of its most recent opposition, based on the lack of ring shadow, as has already been mentioned). Is anyone capable of estimating the kind of scope and camera that might be required to expose Saturn nicely in 0.001 seconds?
I imagine that if one had the gear to expose Saturn nicely in 0.001 seconds, and if the highly variable magnitude of the transiting ISS just happened to be in the same ball park as the magnitude of Saturn, then there is no reason to suppose the task impossible.
I'll note that the other (real) video of the ISS transiting Saturn, posted here recently by Astrofan, appears to have been recorded with quite a small scope. It is a great video, though Saturn is a little underexposed.