My thoughts on the Olympus E-M1 vs. the Panasonic GH4 Background I love buying/trying cameras more than shooting it seems these days. I’ve gone through countless systems in search of the perfect camera/system and as we all know, there is none. At this point it's more about what limitations you can tolerate. It’s about the same as trying to find the perfect camera bag. Out of all the systems I’ve tried (m4/3, APS-C, and FF) I tend to like the micro 4/3 system the most, since it offers the best mix between size, weight, and offers a ton of glass options. That’s not to say that the other systems aren’t good, but there’s always a compromise (Sony APS-C and FF has limited native AF options, Fuji is still working on getting their AF systems up to speed, etc). I shot with the E-P5/E-M5 for about 3 months prior to seeing and pre-ordering the E-M1 after seeing the infamous leak back in August. I received my order from Olympus in late September, then the 12-40 in October. Throughout my shooting the E-M1 I used a combination of the 12-40, 25 f/1.4, and the 45 f/2.8 macro. I bought/sold the 45 f/1.8, and rented the 12-35 f/2.8, the 35-100 f/2.8, and the 7-14 f/4 for a 2 week trip in Asia before the 12-40 was released. I subsequently sold the E-M1 in February as I was tantalized by the X-T1, and as they say the grass isn’t always greener on the other side and seeing that my main needs weren't being met, so I’m returning with the GH4, having had it about 4 days now. Right now I only have the 25 f/1.4 on the Panasonic since I sold all the lenses, but I have a 14-140 f/3.5-5.6 coming in this week, and have a pre-order for the 15 f/1.7 and going to be picking up the Nocticron when it’s on sale (missed the white box specials a few weeks ago). I don’t have the E-M1 anymore, so I can’t do direct comparisons and I’m going off of what I remember from the E-M1 after owning it for 5 months and having another go with a friend’s one a week and a half ago. Image Quality I haven’t had a chance to process any RAWs from the GH4 since I don’t think there’s a converter yet, but based on just initial JPEGs, it’s true, they’re very close to each other. It appears that m4/3 may have hit a limit of sorts, at least at the moment, where IQ seems to have topped out. If tests show that either camera has an advantage over the other, I sure can't see it. Which one I prefer: Tie Build Quality/Weather Sealing Both seem very well built, but if I had to give build quality to one, it would probably be the E-M1. Although there are a lot of reports of dials falling off and malfunctioning, it’s still too early in the GH4’s product cycle to see if it too has build issues. But if I had to trust one of the system’s weather sealing, it would be the E-M1. I took it out when I was shooting in Boston in the winter and it had no issues despite being hammered by snow (with the sealed 12-40). Which one I prefer: E-M1 Grip This is a hard one to pick. They both have pretty sizeable grips, more comfortable to hold that other smaller cameras. The E-M1 is a little shorter, so for me at least adding the RRS L-Plate was beneficial because I liked to use my tripod but having that extra 1/8” had room for my pinky. The GH4 grip height is perfect. The GH4 has a slightly beefier grip, so it’s comfortable and I would say if you have large hands you might prefer it, but I have small-medium hands so it’s a good fit, but a little too deep for me. I felt the E-M1 I could carry around without any strap, just holding by the grip. With the GH4 I made sure that I wrapped the neck strap around my wrist today in 2 hours at the NY Auto Show. The E-M1’s grip depth was just right. Which one I prefer: E-M1 Button Layout/Feel Both have great button layouts. The E-M1 especially is much improved over the E-M5. Both are highly customizable and I love that both have the lockable mode dial. I do really like the GH4’s WB/ISO/Exposure comp buttons at the top. Using that was much quicker for me at least that the E-M1’s 2x2 system. Also have a drive dial on the left side for single, continuous, self-timer, and time lapse is MUCH easier for me than having a HDR/Drive button on the left side of the E-M1. I do like that the touch screen on the GH4 is fully usable, even for menu selection, which the E-M1 you cannot use. Also having the on/off switch in a more natural position on the right makes for easy one handed use, having the on/off on the left on the E-M1 is not a huge problem for me as some people say, but it’s not optimal. Which one I prefer: GH4 Menus/Focus Peaking Some people hate the Olympus menus. I don't mind it so much, sure it's very deep and overwhelming at first. But it's not that old Sony NEX menu, that's for sure. And once you finally get everything customized to your needs, you rarely have to go back into them. But I prefer the GH4's. It's simple, laid out well, and best of all you can use the touch screen to navigate through them. Edit: Wanted to add my thoughts on focus peaking. Focus peaking is much better on the GH4, if only for the simple fact that activating peaking gets you the magnified view as well as having no slow down. I didn't like that using peaking on the E-M1 would bring the FPS down on the camera and slows it down. Which one I prefer: GH4 Viewfinder/LCD Screen The E-M1 has the better EVF, hands down. The GH4 isn’t the worst I’ve used, I would rank it 3 out of the EVF’s that I used (X-T1, E-M1, GH4). Much better than the GX7’s. Both are much improved in low light, lag it noticeable, but with each generation it seems to get better. I do like the fully articulated screen on the GH4, I wish more cameras had it. It’s odd though, there are times when I wish the screen would simply tilt when I was shooting at the NY Auto show today, and I kept on forgetting that I had to flip the screen out first. Shooting out in daylight, flipping the screen out made for harsh viewing, so in bright day light, I think I would’ve preferred a tilt screen. Which one I prefer: E-M1 (viewfinder), GH4 (screen) Auto focus Both are super fast, let’s get that out of the way. I don’t do a ton of high FPS continuous shooting yet, so I can’t really comment on that. I won’t say much about tracking either and I won’t pretend to. I don’t shoot BIF, so if you’re looking for advice on a birding camera, I’m sure that someone else will chime in. I’ve only used one lens that’s the same on both cameras, and the 25 f/1.4 is slightly faster on the GH4, but that’s to be expected due to the DFD. I would imagine that native Panasonic lenses would be better on the GH4. I’ll say this though, I didn’t have a problem with the speed of the E-M1, but I prefer the AF accuracy of the GH4. Whether or not you can attribute this to the DFD, I’m not sure. The E-M1 is super fast but I did have a higher share of misfocused shots with the E-M1, so much so that I preferred to use center AF, and recompose my shots. With the GH4, I use multi zone focus. My missed focus rate is much lower on the GH4. Which one I prefer: GH4 for accuracy. White Balance I tend to be a AWB kind of guy and fix issues in post if needed and the GH4 had some misses in this regard. I would say that shooting in the Javits Center under artificial lighting probably had something to do with it, but I had numerous shots in succession where one image would be very incorrectly metered. But again, that might be attributed to user error. I don’t recall such blatant misses with the E-M1. Which one I prefer: E-M1 Video It depends on what you’re looking for in terms of video. I’ll be forward and I prefer the GH4’s video. The ability to shoot in 4k is huge, but even in 1080, having full control over the shooting is great, and being able to shoot in various codecs and bit rates is fantastic as well. I do miss having IBIS and I’ll admit that shooting with the non-stabilized 25 f/1.4 did result in slightly shakier than wanted video, which I’m sure the 5-axis would’ve helped. The E-M1 has above average video, it’s just that GH4 has great video. The E-M1 has about a 7/10 in terms of video on my scale and trust me I’ve used some cameras where you can see that video is an afterthought (Ricoh GR, Fuji cameras) Which one I prefer: GH4 Why I choose the GH4 over the E-M1 So why did I choose the GH4 over the E-M1? First, I’ll admit I have GAS and want to try the greatest and latest things. I know and loved the E-M1. It gave me great images, I loved the way it felt in my hand, and some of the quirks stopped bothering me after a while. I could’ve easily went back to the E-M1 and had no issues. But when I read about the GH4 I was intrigued. When I saw that it was less than the $2,000 price point which I was expecting, I was intrigued even more. After seeing the Camera Store’s video and seeing how fast the AF appeared, I was sold. Right now in my photographic life the two priorities that I have are quick, accurate AF and great video ability. Both cameras have that. But I dealt with missed focus issues on the E-M1 and really liked the video but I felt that GH4 could improve on that with the DFD and the improved video and so far, so good. Both cameras are fantastic, whichever one you buy you'll have a more than capable camera for 99.9% of photographers. I have nothing bad to say about either, but I'm sure that some who use the E-M1 will tell me that I was doing something wrong, which I don't doubt that I probably was. Best thing to do is you're undecided to find somewhere to give them both a whirl. Last thoughts vs. the X-T1 Really quickly some thoughts about the Fuji X-T1 which is the camera that I sold to come back to the GH4 in comparison to both of these cameras. The X-T1 is a great piece of camera equipment. I see the reason why so many professionals use it, why there are so many more countless blogs and resources about it. The images that it spits out if fantastic. I have to force myself not to look at tomen.de and read all the blog articles about it because it makes me want to give the X system another go. But it’s not the right fit for me. First physics tells us that larger sensor will lead to larger glass. The 18-55 kit lens that I shot with is amazing first and foremost. The 35 f/1.4 which spent the most of the time on my camera is superb as well, but slower to focus. The 14 f/2.8 is by far the best UWA glass I’ve ever used. But even though the AF is much improved over the X-E1, it’s still too slow for MY needs. I could see if my main subjects were static subject such as landscape, architecture, or even the posing portrait, but for me it wasn’t up to speed (pun intended). The buttons were mushy, the video record button was in such an odd place (which after seeing the video that came out of it, I think I know the reason why it was placed in that place). And finally seeing early mockups of the fast glass that’s coming (16-55 f/2.8) for example, they look massive, and they should, they need to fill the same imaging circle as the large Nikon 17-55 f/2.8 and Canon 17-55 f/2.8 which balance nicely on a large DSLR body, but not so much on the smaller mirrorless bodies. Fuji is a great company that really listens to user feedback and it produces some of the best images that I've ever seen (though I'm sure the photographer had a little something to do with it).