Windows XP was the most blissful iteration ... After all, it's arguably most famous for its signature "Bliss" wallpaper depicting a rolling green hill, deep blue sky and little fluffy clouds.

The photo you see above -- the default wallpaper for Windows XP -- is probably the most recognizable image in the world. What you probably didn't know is that it's a real photo, called Bliss ...

The original photo was taken with what's described as a "medium-format" camera. It's an analogue photo originally, captured on film. A full-resolution version of Bliss can be seen here , clocking ...