It could be the 42.4-MP full-frame BSI CMOS sensor which delivers spectacular high-resolution, high-speed and high sensitivity. Reviewers compare its detail-gathering power as approaching that of a medium-frame camera. Gapless on-chip lens design and AR (anti-reflective) coating on the surface of the sensor’s glass seal combine to improve light collection efficiency, resulting in high sensitivity with low-noise performance and wide dynamic range. Some reviewers rank the a7R II as the best low-light camera (perhaps except for the Sony a7S). ISO ranges from 100 to 25600, expandable to ISO 50 to 102400. There is also no optical low pass filter on the camera, delivering the highest possible resolution and clarity.
It could be the 399 focal-plane phase-detection AF points delivering the world’s widest AF coverage on a full-frame sensor and that work together with 25 contrast AF points to achieve fast focus response in both bright and low light. An advanced motion-detection algorithm combines with this Fast Hybrid AF system to achieve up to 5 fps continuous shooting with AF tracking.
It could be the built-in impressive 5-axis sensor-based image stabilization system that corrects camera shake along five axes during shooting, including angular shake (pitch and yaw) that tends to occur with a telephoto lens, shift shake (X and Y axes) which becomes noticeable as magnification increases, and rotational shake (roll) that often affects video recording. This camera shake compensation system is equivalent to shooting at a shutter speed approximately 4.5 steps faster. Effects of the stabilization can be previewed via live-view on the LCD or OLED viewfinder of the camera.
It could be the upgraded XGA OLED Tru-Finder with a double-sided aspherical lens that delivers the world’s highest viewfinder magnification of 0.78x for crystal clear image preview and playback across the entire display area. ZEISS® T* Coating is also utilized to reduce unwanted reflections that interfere with the shooting experience.
It could be the ability to view your image in real-time live-view with exposure compensation, white balance and other effects applied.
It could be the highly durable reduced-vibration shutter with a cycle durability of approximately 500,000 shots. Or, the fact that you can select a Silent Shooting mode which employs an all-electronic shutter in order to shoot silently, without any sensor vibration or movement.
It could be the 4K quality (QFHD 3840×2160) video recording in either Super 35mm crop mode or full-frame mode. Advanced XAVC S7 codec records at a high bit rate of 100 Mbps during 4K recording and 50 Mbps during Full HD shooting. A variety of functions support a professional video workflow including Picture Profile, S-Log2 Gamma and S-Gamut, 120fps high frame rate movie shooting in HD (720p), time code and clean HDMI output.
It could be the built-in Wi-Fi® and NFC or the availability of PlayMemories Mobile™ app and PlayMemories Camera Apps™ which add a range of creative capabilities to the camera (e.g., a new “Angle Shift add-on” app for time-lapse photography allows users to easily add pan, tilt and zoom to time-lapse images without any additional shooting equipment or PC software required).
It could be the growing number of premium grade lenses and accessories. The α7R II is compatible with Sony’s growing lineup of α -mount lenses, which now totals 63 different models including 12 native ‘FE’ full frame lenses. By early 2016, Sony will add an additional 8 new lenses to its FE full frame lineup, bringing the FE total to 20 lenses and the overall α -mount assortment to 70 different models.
It could be the size factor, including the weather-sealed magnesium alloy body.
I am sure other photographers can add their own list of features that helped them decide to finally make the jump from DSLR to mirrorless, but whatever the reason(s), many pro photographers decided the Sony a7R II and its system of lenses and accessories gave them more advantages than their current DSLR system.
The Sony a7R II is by no means a perfect camera, with its confusing menu structure, low battery life, lack of Touch AF, and relatively slow continuous AF for sports photography–but Sony has shown a tremendous desire and capability for continuous improvement and surprising innovation in its cameras, so the story is not finished yet. Many pro photographers will still hold on to their DSLRs for a while longer. I bet it won’t be for too long (though I know a couple who are still holding on to their film SLR).
You can buy the Sony α7R II at B&H:
– Sony Alpha a7R II Mirrorless Digital Camera (Body Only)