NEX-6 - CRAPPED OUT - Shutter remains closed. REFUND imminent - TURN OFF BODY BEFORE SWAPPING LENSES

Photozopia wrote:

I'd suggest it's because the lens contacts are liable to short-circuit, or arc, if not removed cleanly. It may or may not have been in previous manuals - but common sense dictates that removal or disconnection of powered components (even those using micro-voltages & milliamps) is likely to cause sparking or surging across 'close' contact areas.

It's the principle that older car distributors worked on - sparks jump an air gap ... eventually eroding contacts. Or the little blue sparks occasionally seen inside switches or sockets when power flows - as it 'jumps' an opening/closing contact gap - i.e. as the contacts near each other.

It's not rocket science - electrical currents (or more accurately flow electrons) seek the easiest path to ground/continue flowing - a minor air gap, especially in moist/humid conditions, is often a better conductor than many users think possible.

Ask the thousands killed or maimed yearly by this phenomena. In the same way you are advised to switch off domestic power before removing plugs, disconnecting components, etc. then switching off any brand of camera whilst changing lenses is advisable ...