Introduction
Specs
advantages over the Sony a7II
compared to the Canon EOS R
- advantages of the Sony a7III
- advantages of the Canon R
issues
firmware updates
Reviews

Sony a7 III full frame mirrorless camera

Introduction

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

Specs

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
650g
$US1999

advantages over the Sony a7II

better image quality and processing speed
- newly developed Exmor R CMOS sensor with BSI (Back-Illuminated) technology to give 1EV more dynamic range (15 stops)
- has a front-end LSI chip which doubles the readout speed and increases the processing speed by 1.8x with help of a new BIONZ X image processor which should also should improve colour reproduction of skin tones (the dominant yellow tint in JPEGs is now gone) and nature/landscape images
- 40% faster startup time
- improved high ISO performance
- the star eater problem has been eradicated
Much better AF system
- similar to the Sony a9 full frame mirrorless camera
- 693 PDAF points covering 93% of image area instead of only 117 confined to mainly central region
- 425 CDAF points instead of only 25
- more sensitive in low light allows AF down to -3EV instead of only -1EV
- twice the focusing speed in low light and twice the tracking speed
- AF is now available in Focus Magnifier mode
- 4D focus mode
- Eye AF is much improved and now works in AF-S, AF-C and with A-mount lenses, unlike the A7 II with which you could only use it in AF-S and with native E-mount lenses
- new firmware upgrade gives AI-based “Real AF” human and animal eye tracking
Much improved shutter and burst performance
- now has an electronic/silent shutter option
- mechanical shutter burst mode increased from 5fps to 10fps with AF/AE tracking
- buffer is twice as large holding 40 uncompressed RAW files instead of only 20
- burst rates up to 8fps allows live view with blackouts (the A7II at 5fps did not have live view)
- continuous AF works in burst mode at apertures up to f/11 (limited to f/8 in the a7II)
- can now operate the main menu, FN menu and other parameters while the images are being written to the memory card (this is not possible on the a7II)
- Anti-Flicker option to address light sources of 100Hz to 120Hz toi reduce colour anomalies (but reduces burst rate and is not available in e-shutter or movie mode)
- minor improvement to image stabiliser now 5EV up from 4.5EV
Much better video
- 4K 24/25p without sensor crop with full pixel readout, capturing 6K then downscaling to 4K while at 30p there is 1.2x crop (no 4K in the a7II)
- adds Zebra pattern, Gamma Display assist (for S-Log2/S-Log2), proxy recording, Picture Profiles, S-Log3 and HLG (Hybrid Log Gamma)
- in 1080HD it can now do 120p (a7II only reached 50p)and can choose to save the slow motion result in-camera (at 25 or 30p) or keep it at that speed with sound
Much better battery life with the new, larger battery
- same battery as in the a7RII and a9 giving about twice the number of shots
now has a touch screen albeit at LOWER resolution
- can use it to move the focus point, even when composing with the EVF.
same EVF but higher magnification of 0.78x
better build quality and ergonomics
- more robust tripod mount
- similar controls as for a7RII and a9
  - a multi-selector or ‘joystick’ for moving focusing points quickly
  - touch focusing capability
  - ‘AF On’ button
- 50g heavier and slightly larger
- same improved menu as on the a7R III
  - can register up to 30 frequently used items on the new “My Menu”
now with Dual SD slots instead of one UHS-I slot
- first one offering UHS-II compatibility
much improved charging and connectivity
- faster USB 3 port (type C)
- adds Bluetooth to geotag your images
- BUT no longer supports PlayMemories apps
benefits from firmware updates (see below)
- the a7II does not seem to be getting much love in firmware updates

compared to the Canon EOS R

advantages of the Sony a7III

a little cheaper
in-body image stabiliser
dual card slots
better image quality - more dynamic range and better high ISO noise
better Real AF human eye and animal eye tracking but the Canon does well if there is only one person in scene
more consistent C-AF performance although the EOS R was excellent but can have unpredictable hunting issues
less AF points makes it faster to move the selected AF point around
rear joystick
faster burst speed 10fps with C-AF with bigger buffer (Canon R only does 5fps)
flash sync faster 1/250th sec vs 1/200th
battery life is almost twice as good
much better native lens range
much better video quality
- 4K 30p is full sensor pixel readout whereas the Canon R uses a very annoying 1.8x crop and this is reduced further if digital IS is enabled (although Canon's digital IS seems to give smoother video than the Sony IBIS)!
- 1080HD up to 120p instead of just 60p
- sharper, more detailed videos and far better at high ISOs
- less rolling shutter
- better Face detection AF

advantages of the Canon R

larger lens mount diameter may allow more lens design and image quality options in future
significantly larger and thus better physical ergonomics for holding the larger lenses
- Canon R buttons are softer and depress further while the dials are larger and nicer to use however the Mode button is difficult to reach and there is that dubious M-Fn bar slide control which creates a like-hate response and the lack of a joy stick is problematic for many
better EVF (3.7mdot vs 2.36mdot) and easier with glasses
higher resolution LCD (2.1mdots vs 0.9mdots) and the LCD swings out rather than just tilts up/down and the touch screen can also be used to change settings in the Q menu or navigate the main menu
better menu although cannot be customised as with the Sony
better low light AF (down to -6EV with f/1.2 lens and -4.5EV with f/2 lens)
faster S-AF (the Sony apparently tends to prioritise CDAF in S-AF mode which can cause some hunting)
AF works more reliably and faster and at higher burst rates when using Canon EF lenses than when these lenses are used on Sony ¹⁾
top LCD information screen
new shooting mode called Flexible-priority AE (Fv)
Dual Pixel RAW mode
Multiple exposure mode
in-camera RAW processing
Focus Guide MF Assist
the front mechanical curtain closes to protect the sensor when camera is turned off - great for reducing dust when changing lenses
each RF lens has a clicking function ring that can be used for ISO, aperture, shutter speed or exposure compensation and you can set the sensitivity of the focus ring
a few unique native lenses albeit very expensive - 50mm f/1.2 and 85mm f/1.2

issues

slow sensor readout time thus rolling shutter issues, etc.
weathersealing issues with battery door ²⁾
slightly stretches video when shooting 4K full frame - see https://www.youtube.com/watch?v=DmQZIRoMpTU
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:
- https://whatlensshouldiget.com/eye-af-sony-a7iii-how-to-setup-properly/
seems there is a design flaw in shutter which can fail well before the 200,000 shutter count rating - between 10,000 and 50,000 for most of the users but beyond warranty period and users get a vague error: “Camera error. Turn off then on.”.³⁾

firmware updates

v3.0
- adds Interval Shooting for Time Lapse
  - can be set for anywhere between 1 and 60 seconds, with a total number of shots from 1 to 9999
  - AE tracking sensitivity is available to be adjusted to “High”, “Mid” or “Low” in order to reduce changes in exposure
- Real-time Eye AF
  - AI-based system which can detect and focus on the human eye even if the subject is looking down, partially blocked in the frame, turning or backlit.
- Real-time Animal Eye AF
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 ⁴⁾

Reviews

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)
https://amazingsky.net/2018/05/31/testing-the-sony-a7iii-for-astrophotography/
- 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
http://sonyaddict.com/2018/03/17/sony-a7iiis-new-sensor-explored/
- 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”
https://fstoppers.com/originals/camera-you-should-want-fstoppers-reviews-sony-a7-iii-250186
- 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
Youtube review Panasonic G9 compared with Sony A7III
Sony A7III better than a Canon 5DIV for Milky Way astroscape astrophotography
https://www.dpreview.com/videos/3279784857/dpreview-tv-nikon-z6-sony-a7-iii-and-canon-eos-r-compared
- Sony a7III has much better native lens range and is a better all round camera than either the Nikon Z6 (not as good AF or image quality) or Canon R full frame and APS-C mirrorless camera system (worse video, image quality and no IBIS)
https://neilvn.com/tangents/review-sony-a7-iii-mirrorless-camera/