CameraSim is a DSLR simulator that visually explains how camera settings affect a photo. It is a tool for photography newbies and the instructors who teach them.
Use the web app for free: http://camerasim.com/apps/camera-simulator/
The free online app lets you:
• Play with ISO, aperture and shutter speed with the original DSLR camera simulator.
• See what goes on inside a DSLR camera when you snap that photo.
• Work on composition technique and play with exposure
Want more? Go to http://camerasim.com