Day-to-Night photos of NYC from Stephen Wilkes

Following the light paintings and effects by Lichtfaktor, we found some more fresh photography perspectives.
This time, it is Stephen Wilkes' "Day to Night" exhibit in New York's ClampArt gallery (see at Fstoppers).

His idea is to blend day and night views (of NYC, of course) into a single image.  ClampArt describes it as a
"merge of classic street photography and cityscape styles".  Here is the Flatiron Building, my personal favorite:

In order to achieve the effect, Wilkes photographs a scene for a minimum of 10 hours!  Coney Island, below:

Some of the others in this series (see his site, or the gallery) appear to be night photos with unusual lighting --
I prefer the three images linked here because they have a more impactful (to me) difference across the frame.
(Below:  New York Public Library, with Rockefeller Center and part of the skyline in background)

I can't imagine the post-processing involved with producing these, but the result is worth it.  Also would love to see the big physical prints in person.  Exhibit is open through October 29, 2012, for those in or around the Big Apple.