Yes, we are an Authorized US dealer for all cameras we sell, and all them have full US warranties ;-) Other questions? Ask!
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You really can't stop light from bouncing off a mirror unless someone changes the laws of physics. Until then, do like most pbotographers do and change the angle you are shooting from to minimize the reflection or turn the flash off completely. Many indoor shots can be taken without flash if you are willing to wait for a longer exposure time.