Ask the staff: electronic or optical viewfinder?: Digital Photography Review
What is an EVF? - 42 West, the Adorama Learning Center
Should I use the LCD or Viewfinder on my Digital Camera?
What is the Camera Viewfinder? (And How Does it Work?)
Amazon.com : 1.5X Camera Viewfinder, DSLR Fixed Focus Eyepiece Magnifier Viewfinder Eyecup Magnifying for Nikon, for Canon APS-C, for Sony, for Fujifilm, for Kodak, for Sigma, for Leika R, for Olympus :