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Originally Posted by solissydney
If, i could create an artificial shadow on part of the Moon would making the inclusion of a few stars close to the Moon much easier than just taking care with the exposures.
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I can think of two issues with trying to image stars close to a bright moon: (1) exposing for the stars will grossly overexpose the moon and lead to major sensor blooming on a DSLR, and (2) the glare from the moon will drastically brighten the surrounding sky like light pollution.
Without creating a "real" shadow on the moon as Wavytone suggests, I think you'd only really be able to control #1 and not #2.
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I have tried creating a shadow by placing a small black piece of cardboard close to the lens, and also further away, even a couple of meters away. It needs to be in focus in order to be sharp and that I have been unable to achieve.
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Think of it like in normal photography... if you're focused at (effectively) optical infinity, a piece of cardboard close to the lens - or even just a couple of meters away - is sooo far away from the focal plane that you won't be within the depth of field.
If you want a sharp edge, you'd probably either need to use an object further away (e.g. edge of a mountain in the distance), or use an occulting disk very close to (or even directly on) the sensor.
I wonder if using a narrowband filter like Ha would help? You'd drastically cut down on moon glare while still letting a lot of star light through.
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Originally Posted by Wavytone
Between 100% full and fully eclipsed the change in brightness easily exceeds the dynamic range of digital cameras.
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Going by my exposure values for the Jun 2011 lunar eclipse, the difference in brightness from full moon to total eclipse was over 15 stops...
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Short of using a real photo
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Here's a great example.