http://sploid.gizmodo.com/this-is-how-t ... 1483570573
Looks like fun. I hope it catches on. There are just so many cool astronomy photos in the first place, that this technique could really be helpful in getting even more kids interested in the universe.
The technique is simple: open the original image as a base layer. Duplicate the layer and make it out of focus with the Gaussian blur filter. Then add a mask to that layer and use a brush to selectively mask the parts of the image that you would like to keep in focus so it looks as if you were taking a macro photo of a tiny model of the Universe.