>Excuse me for this very uninformed question, but (D)SLR, as far as I can tell, is about using a prism to split light, to allow having a viewfinder. They have

>Excuse me for this very uninformed question, but (D)SLR, as far as I can tell, is about using a prism to split light, to allow having a viewfinder. They have a mirror that reflects light to the view finder. The mirror flips out of the way to let the light hit the sensor. What you describe are called mirror less and is the revolution the article is about. They've been around for a while now but the combination of sensor, battery, and screen improvements have finally reached the point where the disadvantages are mostly gone.