I think the most "wow" thing to most persons who saw the new Portuguese Siderale Scafusia was how the back actually changes color as the time changes. This is something that really cannot be seen, let alone understood, from a static two-dimensional image.
On the back of the watch, as you know there is a star chart the changes with the time of day. During the day it is blue, but at twilight it changes from blue to grey, and then at night it is is grey.
While the above image is too small, on the back there are four red pointers. Two two smaller ones closer to the time show sunrise and sunset (since night varies each day during the year). Slightly larger inner red pointers show the time, since you can see different stars at different positions depending on the time.
Now, we made a quick amateur movie of the change from blue to grey and then back to blue again. I held the watch while Thomas Gaeumann, head of research and development at IWC, twisted the crown, changing the time. Look carefully and you'll see the changes in color --amazing!
People asked how this could be accomplished, and it's basically two concentric polarized crystals that, when overlap, change color. These invisible crystal dials move as the time changes, and are triggered by sunrise and sunset.
A word of warning --the movie linked below is 30 seconds and involves a lot of data. So --be patient, and then be amazed.
[click here for 30 second movie](http://gallery.me.com/kbereskin#100716)
