When comparing Olympus OM-D E-M1 vs Fujifilm X-T1, the Slant community recommends Olympus OM-D E-M1 for most people. In the question“What are the best mirrorless cameras?” Olympus OM-D E-M1 is ranked 1st while Fujifilm X-T1 is ranked 5th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Amazing image stabilization
Pro Supports standard Four Thirds lenses
Built-in phase detection allows you to use standard Four Thirds lenses via an adaptor.
Pro Good electric viewfinder
The viewfinder is bright and sharp.
Pro Great focusing system
The focusing system is quick, it rarely if ever resorts to focus hunting and it's consistently accurate.
Pro In-body stabilization saves money on lenses
Since stabilization can be applied to any lense, you can save money by not having to spend it on stabilized lenses which are generally more expensive than non-stabilized lenses.
Pro Convenient in-camera RAW conversion
Pro Quick access to settings
The camera takes a "buttons and dials for everything" approach. It's also possible to change what some of the buttons do.
Pro Great image quality
E-M1 takes sharp 16MP images with tonal colors. There's little noise up until 1250 ISO and there's little smudging up until 6400 ISO.
Pro Continuous autofocus works well at a distance
Continuous autofocus is reasonably reliable using long lenses at a distance. It works slightly better with the subject coming closer/moving away from the camera than it does when the subject is moving from side to side.
Pro Can preview HDR images in viewfinder
HDR images can be composited in-camera and the output seen using the viewfinder.
Pro MFT lens mount allows for a wide variety of lenses to choose from
Micro Four Thirds system is a standard used by Panasonic, Olympus, Sigma and many others so you're not locked into a having to buy lenses from one manufacturer.
Pro Great image quality
Good colors, lots of detail and little noise up to 6400 ISO (though Fujifilm's 6400 ISO is closer to 4000 ISO in other cameras). The camera adjusts the white balance pretty accurately in all kinds of conditions.
Pro Great viewfinder
It has a huge viewfinder with a 0.77x equivalent magnification. The size of the viewfinder allows for additional functionality such as displaying an enlarged image next to the overall image and turning the image to portrait view when the camera is turned sideways.
Pro Good auto white balance
Pro Good in-camera RAW conversion
Pro Quiet shutter
Cons
Con Video quality could be better
The video is limited to 24MBit max bitrate.
Con Limited framerate options
Shooting in 1080p the camera is limited to 30fps, there are no slow-mo options or 24fps options.
Con Continuous autofocus is spotty at close range
Continuous autofocus is sometimes seen hunting with wide angle lenses at short range.
Con Power switch placement can feel inconvenient
Con Somewhat unintutive RAW conversion interface
Con The depth of interface options can be overwhelming at first
Con Limited control over video
The camera will automatically adjust exposure. ISO and shutter speed is ignored. And so is exposure compensation past +/-2 EV. There's also no way to adjust aperture during recording, it has to be set before you start shooting.
Con Autofocus varies highly depending on lens used
X-T1 works amazingly well with internal focus lenses while being really slow with older X-system lenses.