Oron,
Just an idea, but I keep thinking about the background. Will changing the apreture be enough to make the effect? will it be smooth enough? what about the way the light hits the hills in the background?
What if you do this in time lapse? really utilizing the sunset and sunrise. I don't know what lens and aspect ratio you're planning on shooting at , but the Judean desert is such an amazing place, with incredible sunsets/sunrises, why not let it show for what it is?
As I said, just an idea... not necesserily very realistic. Anyway, good luck and let us know how it came out.
P.S. assuming you don't have the money to do tests, I would consider at least testing with stills (be it 35mm or digital) and smaller units, to see if this is what you're looking for.