Not having the willpower to say no to such things, I went ahead and purchased the Olympus 12-100 f4 lens. After looking closely at my use of lenses I came to the conclusion most of my images were taken between 12mm and 200mm and not really being a lover lens changes, the 12-100 f4 would be my ideal “travel” lens.
My last holiday was done with 2 Panasonic GM5 cameras paired with the Panasonic 12-32 f3.5-5.6 and the 35-100 f4.0-5.6. Both of those lenses were made for the GM series cameras. I didn’t feel then that I was lacking in focal length beyond the 35-100 and I managed to get all the images I was going for.
The 12-100 is a member of the Olympus Pro family as the weight and construction shows.
Weight: 561g
Size: 117mm x 78mm
Aperture: f4 – f22
MFD: 1.5cm @12mm, 27cm @100mm
Filter: 72mm
Price: €1300
Being an f4 lens, equivalent to f8 on a full frame camera, we can’t really class it as a “fast” lens. Lenses tent to sharpest when stopped down a couple of stops from wide open, which would take us to f8 (f16 equivalent). I tend to use f8 on M43 cameras a lot actually but a lot of M43 users would condemn stating diffraction would start to show it’s ugly head. I disagree with them on this point. But that is just my thoughts on things, you might have other ideas. I’m assuming at this stage that f5.6 will be the optimum aperture for this lens.
I’ve had the opportunity to use this lens now on a couple of occasions but I’m still holding out on calling a stellar performer or such things. I waited some time before I actually purchased this lens, waiting to read some reviews before doing so. Needless to say, all review I read were excellent and couldn’t really flaw the lens at all. I’m going to be using it on another couple of trips before I pass judgement as I’m not 100% convinced at this stage if my copy is stellar or not.
However, having looked through the following images, sharpness does seem to be there from f4 onwards. Micro contrast is good with pleasing colours. Something still bothers me though about the lens. The weight, the balance, or maybe I haven't got used to it yet, that's all. I haven't been able to find a bad review of this lens yet so I'm assuming at this pint that the problem mus lie with me.
Some images taken on an lovely spring day not too long ago. Actually since that day it's been terrible here in Germany. Cold, rainy and very cloudy. I hope there will be some sort of summer this year 
Judge for yourselves if this lens is a winner or not.
Bokeh @f4 and full zoom 100mm
DOF @20mm f8
Bokeh @f4
Bokeh @f4, 75mm
Olympus blue?
Vibrant and accurate colours
That blue again
Probably my best image of the day
What I do know right now is the lens is a bit of an all-rounder. It produced the goods on everything I asked it to do, and it did it well. I'll be updating this when I've had a little bit more use out of the lens. The weight doesn't bother me one bit, not that it's that heavy, but I find having a body like the E-M1 of G81 will help balance out the lens on the body.
