i have the deluxe model. on the finder where the intensity knob is, right in front of the screen. You'll notice that the top of the dial has a grove. if you unscrew it you'll find the battery. looks like a typical watch battery. i thought it was weird that the red dot finder would stop working like that but i cant think of anything else it could be but the battery.

How do you turn off the red dot finder when you arent using it? put the dial at 0?