Both camera features advance AF technologies inside and fullframe sensor, take a look at the specification comparison review of your fav machine and see the core difference between them…
Sony Alpha 7 vs. Nikon D750 Specification Comparison Table.
Sensor: Sony A7 comes with 24.3 megapixels Exmor CMOS sensor that is capable to captures high-resolution, low-noise images with rich tonal gradation and low-light sensitivity. on the other hand NikonD750 comes with a 24.3MP FX-format CMOS sensor that ensures better quality images. There is not much difference between the sensors of both the camera.
AF System: Both the camera features the same contrast detect + phase detect (hybrid) focusing method to acquire fast and precise focus over subjects. The phase detect method provides quick response focusing while contrast detect method fine-tunes the focused area. While working together both these methods result in dramatically high focusing.
AF points: Sony A7 offers a total of 117 AF points whereas NikonD750 offers a total of 51 AF points among which we can select 9, 21, 51 points.
ISO: With a better ISO range, NikonD750 helps the user while taking shots in different lightning situations. The ISO flexibility allows user to control the amount of light entering the lens barrel. NikonD750 provides excellent images in low lightning conditions as well as in bright conditions too.
Shutter speed: The shutter speed of Sony alpha 7 is far better than that of NikonD750. With better shutter speed Sony alpha7 is capable to produce sharp images of even the fastest moving objects. It is ideal for sports photography.
Top shooting speed: NikonD750 can take up to 8 shots continuously is a second. Whereas Sony A7 can take 5 shots in a second.
Video: With Sony A7 we can capture full HD 1920 X 1080p videos @60fps 1440 x 1080p videos @30fps and 640 x 480p videos @30fps
And Nikon D750 we can record full HD 1080p videos at multiple frame rates up to 60fps. It provides full manual control over shutter speed aperture and ISO settings during recording the video.
Display: The tiltable 3.0″ Xtra Fine LCD Display of Sony a7 offers a 1,229K-dot resolution and provides ease to photographer to shoot from both high and low angles by swinging up 84° and down 45°. Whereas Nikon D750 offers 3.2″ 1,229k-dot LCD monitor which has a tilting design to make it easy for the photographer while shooting at high or low angles angles.
viewfinder: Sony a7 features an electronic viewfinder that helps the photographer to monitor the subject while shooting in a bright lightning condition. While Nikon D750 has an advanced optical viewfinder which provides better clarity when compared to the electronic type viewfinder.
Connectivity: Both the cameras feature in built WI-FI that allows them to connect to smartphones and tablets running on the iOS and Android platformfor. Image sharing as well as remote control feature can be accessed by the smartphone over the camera. However Sony a7 also features NFC (Near Field Communication) which creates wireless connection between two devices by simply tapping the two devices. Wireless connectivity is more easy and beneficial with Sony a7.
Battery: Nikon D750 has an excellent battery life and it can take up to 1230 shots in one battery cycle. While Sony a7 can take up to 340 shots in one battery cycle.
Dimensions: Sony A7 is has a small body in comparison to that of Nikon D750
Weight: Sony A7 weighs less than Nikon D750.
Verdict: We have no doubt that Sony A7 has advance AF system and better connectivity option than of Nikon D750, but the Nikon D750 offers more ISO range and continuous shooting speed than Sony A7 and above all the lens support of Nikon D750 is fabulous and a wide range of lenses are available to choose from.