see also:

• Sony NEX E-mount camera system
• Sony NEX FX full frame mirrorless cameras
  • Sony a9 full frame mirrorless camera
  • Sony a7R III full frame mirrorless camera
  • Sony a7S II full frame mirrorless camera
  • Sony a7 II full frame mirrorless camera
• Sony FE E-mount full frame lenses
• tips on how to use the Sony a7 series cameras
• Sony website

• announced Feb 2018
• boasts most of the Sony a9 full frame mirrorless camera speed, as well as features from both the Sony a9 full frame mirrorless camera and Sony a7R III full frame mirrorless camera
• feels and looks like the Sony a7R III full frame mirrorless camera
• faster sensor readout and thus almost twice the AF speed and accuracy compared to the Sony a7 II full frame mirrorless camera and the much improved Eye AF of the Sony a9 full frame mirrorless camera which works even in C-AF mode or when using Sony A mount lenses, plus the addition of:
  • a multi-selector or ‘joystick’ for moving focusing points quickly
  • touch focusing capability
  • AF availability in Focus Magnifier mode
  • ‘AF On’ button
• the Eye AF and low light capabilities with sensor based IS make it high on the list as an ideal wedding photography camera - the Sony 85mm f/1.4 lens is looking like it may be very popular for this camera

• new 24.2mp full frame back-illuminated Exmor R CMOS sensor for enhanced color and IQ and low light capabilities (said to be 1.5EV better than the Sony a7 II full frame mirrorless camera and with improved dynamic range of 15EV at ISO 100)
• 5-axis 5EV sensor based image stabiliser
• 425 contrast AF points that work with a 693-point focal-plane phase-detection AF system inherited from the Sony a9 full frame mirrorless camera, covering 93% of the frame
• ISO to 204,000
• 14 bit RAW format even in silent and continuous shooting modes
• 10 fps with continuous, accurate AF/AE tracking for up to 177 Standard JPEG images, 89 compressed RAW images or 40 uncompressed RAW images in eitehr mechanical or silent, electronic shutter mode
• 8 fps in live view mode with minimal lag in the viewfinder or LCD screen
• 2.3mdots EVF
• dual card slots but only one slot for UHS-II type SD memory cards.
• 4K video
  • uses full pixel readout without pixel binning to collect about 2.4x the amount of data required for 4K movies, and then oversamples it to produce high quality 4K footage with exceptional detail and depth
  • HLG (Hybrid Log-Gamma) picture profile
  • S-Log2 and S-Log3 are available for increased color grading flexibility
  • Zebra functionality, Gamma Display assist and proxy recording
• Full HD at 120 fps at up to 100 Mbps with AF tracking
• much improved battery life of 710 shots per charge BUT uses Sony’s Z series battery NP-FZ100 that have approximately 2.2 times the capacity of the W series battery NP-FW50 utilized in the α7 II
• WiFi
• SuperSpeed USB (USB 3.1 Gen 1) USB Type-C Terminal
• $US1999

• my blog post - a7III vs a7II vs a7RIII vs a9
• https://www.dpreview.com/articles/3389926460/sony-a7-iii-dynamic-range-and-high-iso-improve-over-its-predecessor
  • due to the dual-gain architecture, there are two 'ISO-invariant' ranges: ISO 100-500, and ISO 640-51,200.
    • “ This means that if your midtone exposure demands ISO 400 but you're worried about clipping highlights, you're better off keeping your exposure settings the same but dialing the camera back to ISO 100 and then selectively brightening the Raw later. This affords you 2 EV extra highlight headroom, with no extra noise in shadows or midtones. ”
    • “If on the other hand your midtone exposure demands ISO 6400, you're better off keeping the same shutter speed and aperture and dialing the ISO down to ISO 640, affording you 3.3 EV extra highlight headroom at no noise cost”
  • similar high ISO noise as the a7RIII and much better than the a7II
  • uncompressed RAW gives similar dynamic range as the a7II from ISO 100-600 but thanks to the dual-gain design, the a7III has 1.6EV more dynamic range at ISO's at ISO 640 and above - such that you probably should avoid shooting at ISO 500-600 on the a7III - just use the base of 640 instead for better results
  • uncompressed RAW gives a 1EV more dynamic range than with the a9
  • compressed RAW in continuous burst drops from 14bit to 12bit sensor readout, and this results in around 1.4EV less dynamic range than with uncompressed RAW at base ISO (1.0EV less at ISO 640, and 0.4EV less at higher than 3200)