Olympus OMD EM-5 body + the 45mm as my only lens (is it possible?)

I would think that would have to a personal choice based on what and how you shoot.  But couldn't you just spend a day or two visiting some favourite subjects with any zoom-camera that can do the 45mm (90mm) and not change the zoom.  Then you'd just need to factor in the 45's added light and reduced DOF.

Personally I'd want at least a 17mm as well as the 45mm, and probably also the 12mm - but that's just me.

I've been pretty happy with the 12-50 - suits my needs - outdoors mostly.

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