I ended up writing the below post on a forum in response to a DSLR owner, who for health reasons was considering a move to micro four thirds. The chap concerned, perfectly reasonably, had decided that he was going to make the move from a Nikon D800 setup to a E-M5. For reasons I’m not quite sure I even understand (!) I wrote a compare and contrast of the E-M5 and GH3 (I’ll admit pointing to why I prefer the GH3) in response to his query and afterward thought it wasn’t a bad write up of the differences between the cameras. As a consequence it is making its way here…
Note that this was written from a stills perspective, so no comments on video in my original comparison.
I saw your other posts that you were settled on the OM-D E-M5. It makes sense to me that someone with issues around weight of bodies and lenses might choose Micro Four Thirds and further that you might choose the E-M5 (the actual model name of what you know as the OM-D, which is the name of the line) which is one of the smaller bodies.
Just a word of caution, the HLD-6 grip that Olympus sell is great if you have medium to small hands, not so great if you have medium to large hands. Why?
Weight: The body of the E-M5 is relatively heavy (probably down to the IBIS) but small. It doesn’t act as much of a counterweight for the lens and if the rear of your fingers isn’t against the front of the grip it can become uncomfortable with larger lenses. I noticed this when doing an extended test of the Panasonic 35-100mm lens on the E-M5 and realised the depth of the grip wasn’t so comfortable for my hands.
Oddly enough it’s not just a weight, but a weight and size thing. The 35-100 is lighter than the Olympus 75 but is longer. The 75 is OK on the E-M5 (it feels balanced) whereas the 35-100 does not.
Ergonomics/Controls: That experience led me to the Panasonic Micro Four Thirds cameras and ultimately to the GH3, which is considerably more ergonomic. I’m now firmly of the opinion that the E-M5 is great with the smaller primes but less good with some of the larger lenses in my system. IBIS is fine but I would personally prefer to have a physical control to turn stabilisation on or off. I also prefer that the GH3 has more physical controls than the E-M5, which means that the experience is far closer to a DSLR than your average mirrorless camera (see this comparison here: http://j.mp/PLX99T and look at the rear and top views of each camera). Note that some people have an extreme reaction to the GH3 EVF (they say it’s blurry in use), my own unit has an EVF that is bright and very clear (and, for me, superior to the E-M5 EVF) since I adjusted the diopter when I got it.
In any event you might like to read this post which was essentially my first reaction to the GH3: http://wp.me/p2wMAg-iz
Tracking/Autofocus: It’s probably also worth me noting that AF tracking IS usable on the GH3 (whereas I don’t think it is on the E-M5). It’s comparable to something like a low end APS-C DSLR, not what you would be used to, but as I say, useable. I’m not sure I would use it for BIF but for tracking sports or cars etc it works.
Also worth noting that I think the single shot autofocus on the GH3 is faster (by a hair) than the E-M5 – to be honest, I think you’ll find both the GH3 and the E-M5 very fast to autofocus indeed (at least as fast as a DSLR, if not faster). Any difference in AF speed/abilities comes down to the development of the GH3 for video, which requires very fast data connections and processors in camera. I read somewhere that the GH3 is (in theory) twice as fast as the E-M5 because of its processing abilities, but it hasn’t worked out like that in real world use for me.
For the GH3 (multiply by 2 for the FF equivalent FOV) I use (all Panasonic lenses): 12-35mm F2.8, 35-100mm F2.8 and the 7-14mm F4. All three of those lenses are amongst the best lenses for the system. In particular the 7-14 is every bit the equal optically to the Zeiss 16-35 I used to have for my A900.
For the E-M5 (multiply by 2 for the FF equivalent FOV) I use (all Olympus lenses): 12mm F2, 17mm F1.8, 45mm F1.8 and 75mm F1.8.
Interchangeably I use the Panasonic/Leica 25mm F1.4, Panasonic 45mm F2.8 (should probably sell this one), Olympus 60mm F2.8 Macro (excellent), and I have both the Oly 75-300 Mk I and the Panny 100-300 (one of which I should sell). I also use both Voigtlander Noktons (F0.95) of which only the 17.5 is worth the price IMO. It’s a problem working out when to use it though because it’s really heavy – it handles better on the Gh3 but the IBIS on the E-M5 is realy helpful for low-light shots.
If you could only get a few lenses, get any of the 7-14, 12-35, 45, 60 and 75. The only telephoto zoom I really rate is the 35-100 but (while it is excellent) I haven’t listed it because it’s somewhat duplicative of the 75 and the 75 is off the scale good (take a look at these: http://wp.me/p2wMAg-6l ). The 75 gives some good results with the GH3 too (see the last 3 shots on this post:http://wp.me/p2wMAg-iK).
Lens Corrections: All lenses are interchangeable on either brand of camera but note that all lenses are electronically corrected for distortion. This data is embedded in the RAW files so there is no need to select lens profiles in Lightroom et al. Panasonic lenses are automatically corrected for CA on panasonic bodies (though not on Olympus bodies), though some correction of fringing in post may still be necessary on the worst shots.
My conclusions? If you can, try out both bodies in person before taking the plunge. If you are set on the E-M5 it is a nice camera (the same could equally be said of the GH3) but some people seem to have an affinity for one and not the other after using both… Don’t confine yourself to one brand of lenses, whichever camera you get.
I noticed in the above I didn’t really get into image quality. To be honest, what’s the point? It’s largely the same, with some difference in colours and exposure between both cameras (which can largely be replicated in RAW processing). I still think the GH3 gives me better image quality overall, but I suspect that comes down to more keepers (because the controls and ergonomics are much better for me) rather than a substantive difference (though part of me still wonders about my initial reaction, which is rarely wrong…). Further, I didn’t mention the silent electronic shutter of the GH3, but I mainly find that useful as a way of minimising camera shake at low shutter speeds – the GH3 shutter isn’t exactly loud anyway (similar to the E-M5’s). As I said above, this was from a stills perspective. I won’t go into video features in depth other than to observe that the GH3 has far, far superior video capabilities (it was designed from the ground up for video) whereas the E-M5 is very much a stills camera where video is an afterthought. What the E-M5 does have going for it is IBIS, bit it simply cannot compete with the range of file formats, bit rates and output sizes available from the GH3.
The outcome – the chap concerned told me he had had small hands, wanted to shoot primes and didn’t use tracking, thus his preference for the E-M5 (which makes perfect sense to me). He was headed to a camera shop this week to try out the E-M5, GH3 and Fuji X-E1 side by side to confirm his decision.