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Sony a7 III full frame mirrorless 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


  • slightly stretches video when shooting 4K full frame - see
  • video REC button cannot be programmed, and only works in Movie Mode
  • no battery charger included - that's an optional extra at over $100!
  • no longer can use PlayMemories apps and no Multiple Exposure built in
  • silent electronic shutter only goes to 1/8000th sec, not 1/32,000th sec
  • formatting memory cards is slow
  • electronic front curtain can cause banding when using flash
  • using the awesome Eye AF tracking requires some tweaking:

firmware updates

  • v2.10
    • released Dec 2018 addressed the bugs introduced with v 2.0
  • v2.0
    • released Dec 2018
    • unlocks all autofocus modes (eg. subject-tracking Lock-on AF modes, Zone and Expand Flexible Spot) for adapted lenses adapted with the Sony LA-EA3 mount adapter and these seem to work with Canon EF lenses on either the Sigma or Metabones adapter
    • new 'Aperture Drive in AF'which allows AF to be acquired with aperture at f/2 instead of at selected slower aperture which allows faster AF
    • general improvements to operation and to flash exposures near flickering light sources
    • version 2.0 is buggy and causes issues and has been withdrawn 1)


    • 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)
    • seems the star eating issue is now gone with this model at last
    • similar noise as the Nikon D750 at ISO 800-6400, and much better than the Canon 6D II, and good but not great ISO invariance (the Nikon D750 was much better here)
    • when using LENR Raw images are recorded with only 12-bit depth, not 14-bit, and using LENR seemed to marginally add some noise and did not remove all hot pixels and does not remove the amp glow
    • the Bright Monitoring function is hard to find in the menu (Camera Settings 2 page, Still Image–Custom Key, custom button) -this allows the live view image to be so bright you can actually see the Milky Way live on screen making framing much easier
    • showed some slight edge-of-frame shadowing from the mask in front of the sensor, as well as a weak purple amp glow
    • lacks any internal intervalometer or ability to add one via an app - must be used with an external Intervalometer via the multi USB port
    • no Bulb Timer
    • no Multiple Exposure modes for in-camera stacking of exposures in a Brighten mode (for star trails) or Averaging mode (for noise smoothing)
    • buttons are not illuminated
    • red sensitivity for recording H-Alpha-emitting nebulas was poor.
    • lacks the “light-frame” buffer offered by full-frame Canons that allows shooting several frames in quick succession even with LENR turned on
    • video shutter speeds can be as slow as 1/4-second, allowing real-time bright aurora shooting at reasonable ISO speeds of ISO 6400-12,800 when using f/1.4-f/2 apertures
    • 400-frame time-lapses used about 40% of the battery capacity, similar to the other DSLRs
    • dark shadows in underexposed nightscapes withstood shadow recovery better in the uncompressed files than in compressed RAW mode
    • good, though not great, for long-exposure deep-sky imaging (eg. nebulae) - the Canon 6D MkII is better than the Sony or Nikon D750 for this niche
    • Photons to Photos testing shows the a7III read noise is:
      • similar to the a7II up until ISO 500 but then is greatly improved from ISO 640 onwards when it beats all other Sony cameras except for the Sony a7S which does better than the a7III from ISO 1200 onwards
    • “The a7 III’s image quality more or less matches what we’ve come to expect from modern, well-performing full-frame sensors. There’s really not much difference between the a7 III, the a7R III, the a7R II, or the Nikon D850 for that matter”
    • Eye AF good enough to track someone running towards the camera with C-AF
    • menu system still confusing
    • AF regions in EVF can be difficult to see
photo/sonya7iii.txt · Last modified: 2018/12/20 19:49 by gary1