The background
Being a Nikon user for the last ten years I faithfully bought a Nikon V1 on sale early in 2013 to complement my full-frame D600 setup - just something to bring along on small trips and to used by non-technicals as well.
Quite surprisingly I started to use the V1 more and more, and the D600 less and less. D600 had superior image quality, but the V1 had "good-enough" IQ and a stunning fast AF - perfect for tracking small kids in motion. The V1 and its 18,5mm gave me some fantastic results, but I wasn't ready to let go of the full frame.
The push
During the autumn 2012 I started noticed the glowing reviews of the E-M1. The reviewers claimed it was good enough to replace a full frame for an enthusiast. The size and weather sealing was very attractive features, but it was finally kit lens that pushed me. A 24-80mm full frame equivalent f2.8 weather sealed lens at that size (and price) and another 80-300mm full frame equivalent f2.8 weather sealed lens on the road map!
The move
I'm not going to write a lengthy treatise about the obvious merits of the E-M1 - it is a superb camera. The size of the setup (camera and lens) is good. the weathersealing is promising and the kit lens is fantastic. I would rather like to dwell on the experience made after moving from Nikon fullframe camera (D600) and what prospective Nikonian should consider.
Image quality
The key issue for full-format user is the image quality - what will I lose? Many, if not all, of the reviews told that the IQ of the E-M1 were comparable to fullframe and hard to distinguish in real life. Well, there is a difference and I noticed it. Even in base ISO, but in particular at ISO 800 and above, the photos are more smudgy, in lack of a better word, compared to the D600 when pixel peeping. But so far the IQ, has been good enough in real-life and the sharpness of the E-M1 and the 12-40mm combo is stunning at times.
Megapixels
Moving from 24 to 16 megapixels was a major concern for me due to limited opportuniy for cropping. I often crop my keepers, subject isolation or changing orientation or aspect ratio (those who manage to do this in-camera - kudos to you). 24 megapixels is naturally more forgiving than 16 in terms of final image quality after cropping, especially if the final result ends enlarged on the wall. So far, not an issue for me.
Aspect ratio
I was also concerned about the 4:3 aspect ratio and after 4 months I'm still no comfortable with it, but I'm coping. Not a big issue, but for landscape orientation I do miss the 2:3 and I tend to crop a bit.
Controls
Olympus menu and controls was a concern, but not anymore. Direct access to most of required settings and lots of room for customisation, no problem at all.
Colours
The major grievance, and the one I did not expect is the colours. Every Olympus user seems to marvel about the Olympus colours, but I've a hard time in getting consistent correct colours. I import the raw file (orf) in Lightroom 5.3 (not RC) with camera neutral profile, but the colours are sometime off. This applies for especially for photographs taken indoors. The E-M1 seems to strives to automatically assign white-balance values compared to Nikons. Photos from one particular place indoors may results in various WB values. I've tried to assign auto and manual WB in Lightroom, but still the colour for some photos are off. The colours from Nikon D600 and V1 were seldom a problem, and when correcting WB in Lightroom it was resulted in correct colours. I don't know if this is in fact is a fault (user, software or hardware) or just an adjustment from Nikon colours and tonality. Anyway, I need to investigate this issue more.
Being a Nikon user for the last ten years I faithfully bought a Nikon V1 on sale early in 2013 to complement my full-frame D600 setup - just something to bring along on small trips and to used by non-technicals as well.
Quite surprisingly I started to use the V1 more and more, and the D600 less and less. D600 had superior image quality, but the V1 had "good-enough" IQ and a stunning fast AF - perfect for tracking small kids in motion. The V1 and its 18,5mm gave me some fantastic results, but I wasn't ready to let go of the full frame.
The push
During the autumn 2012 I started noticed the glowing reviews of the E-M1. The reviewers claimed it was good enough to replace a full frame for an enthusiast. The size and weather sealing was very attractive features, but it was finally kit lens that pushed me. A 24-80mm full frame equivalent f2.8 weather sealed lens at that size (and price) and another 80-300mm full frame equivalent f2.8 weather sealed lens on the road map!
The move
I'm not going to write a lengthy treatise about the obvious merits of the E-M1 - it is a superb camera. The size of the setup (camera and lens) is good. the weathersealing is promising and the kit lens is fantastic. I would rather like to dwell on the experience made after moving from Nikon fullframe camera (D600) and what prospective Nikonian should consider.
Image quality
The key issue for full-format user is the image quality - what will I lose? Many, if not all, of the reviews told that the IQ of the E-M1 were comparable to fullframe and hard to distinguish in real life. Well, there is a difference and I noticed it. Even in base ISO, but in particular at ISO 800 and above, the photos are more smudgy, in lack of a better word, compared to the D600 when pixel peeping. But so far the IQ, has been good enough in real-life and the sharpness of the E-M1 and the 12-40mm combo is stunning at times.
Megapixels
Moving from 24 to 16 megapixels was a major concern for me due to limited opportuniy for cropping. I often crop my keepers, subject isolation or changing orientation or aspect ratio (those who manage to do this in-camera - kudos to you). 24 megapixels is naturally more forgiving than 16 in terms of final image quality after cropping, especially if the final result ends enlarged on the wall. So far, not an issue for me.
Aspect ratio
I was also concerned about the 4:3 aspect ratio and after 4 months I'm still no comfortable with it, but I'm coping. Not a big issue, but for landscape orientation I do miss the 2:3 and I tend to crop a bit.
Controls
Olympus menu and controls was a concern, but not anymore. Direct access to most of required settings and lots of room for customisation, no problem at all.
Colours
The major grievance, and the one I did not expect is the colours. Every Olympus user seems to marvel about the Olympus colours, but I've a hard time in getting consistent correct colours. I import the raw file (orf) in Lightroom 5.3 (not RC) with camera neutral profile, but the colours are sometime off. This applies for especially for photographs taken indoors. The E-M1 seems to strives to automatically assign white-balance values compared to Nikons. Photos from one particular place indoors may results in various WB values. I've tried to assign auto and manual WB in Lightroom, but still the colour for some photos are off. The colours from Nikon D600 and V1 were seldom a problem, and when correcting WB in Lightroom it was resulted in correct colours. I don't know if this is in fact is a fault (user, software or hardware) or just an adjustment from Nikon colours and tonality. Anyway, I need to investigate this issue more.

