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Sony A9

In 2017 Sony introduced the first professional, full-frame, mirrorless camera. Enabled by the world's first stacked sensor, the A9 could finally compete with the best professional full frame DSLRs out there, but in total silence. After nearly seven years of service (wow, has it been that long?!), what impact did the A9 have on the market and is it still competitive as a high-end professional camera?

Sony A9 with Sony 135GM

Key Specifiations




DR Stops:



AF points:


Vid Qual:







Full Frame CMOS


20fps / 244 shots

10.47 (14bit**)


30s - 1/32,000th

693 (93%)

1080p/120 | 4k/24

4:2:0 / 8bit

100 - 32,000

0.77x / 1003.6m / 120hz

3" / 1.44m / Flip only

SD (x2)


650 (NP-FZ100)

Pro DSLR Killer

Compared to professional DSLRs of the time, the Sony A9 was substantially smaller, lighter and cheaper. Those are highly important factors to some, but often get brushed off by "pros". Fortunately the A9 also brought some pretty impressive features. Things like: Higher burst & shutter speeds, a higher-resolution & stabilized sensor, a large viewfinder with zero blackout, reliable and fast eye-AF (including animals), extremely reliable AF tracking and last but certainly not least... silent shooting with almost zero rolling shutter.


With substantial speed improvements across the board, huge size & weight advantages and several killer features... The A9 took mirrorless cameras from fun alternatives to consumer DSLRs to objectively better than every DSLR. It's difficult to overstate just how much of a pivotal shift in camera technology this was. Five years on; Canon and Nikon both now have their own pro mirrorless cameras and rumours are rife with DSLR production soon slowing or stopping entirely. To illustrate why the A9 generated so much fear from the established companies; Here's a list of improvements that the Sony A9 has over the Nikon D6 (2020) which came out 3 years later...

  • Silent shooting (+ low rolling shutter)

  • Blackout-Free Viewfinder (120fps)

  • Faster & more Advanced Focusing

  • Higher Resolution (24mp)

  • Higher Burst Speeds (20fps)

  • Animal Eye-AF (& Tracking)

  • More AF points (>700%)

  • Larger Focus Area (>400%)

  • Better Low-Light (DxO)

  • Longer buffer (20fps @ 12s)

  • Image Stabilization (5 stops)

  • Tilting Rear Screen (1.4m dot)

  • Lower Shutter Lag (More responsive)

  • Higher Shutter Speeds (1/32,000th)

  • Much Lighter (Less than half)

  • Much Smaller (shown here, to scale)

  • Much Cheaper (~1/3)

This list illustrates how quickly and dramatically DSLRs have been left behind. The only seemingly clear win for the Nikon here is battery life and even that is not as cut and dry when you dive into the details (see battery life section below, to see what I mean). Even things that don't easily compare on paper (like AF and EVF usability) are a big win for mirrorless here. Being half the cost, as well as half the size & half the weight really make a big difference, but for me it is the silent & blackout free shooting (without rolling shutter issuesthat really make this a DSLR killer. Everything else is just nice to have.


Switching from a DSLR's optical viewfinder (OVF), to a mirrorless camera's electronic one (EVF) will certainly feel strange at first. Of course it has finite limitations (like resolution and frame-rate) which can initially feel like a downgrade, but it's worth considering its numerous and significant benefits before disregarding this as a benefit to the DSLR:

  • Silent Shooting - Shoot electronically to make no noise at all, but still be able to see using the viewfinder

  • Live Exposure - No more guessing exposure or dynamic range. Shooting full manual is also much easier and faster

  • AF Sensors - Many more focus points over a much greater part of the frame for more accurate focus and better tracking

  • Eye-AF - The ability to lock focus and track the eyes of people (plus many animals)

  • No Chimping - Reviewing images is now unnecessary since exposure values are seen in real-time

  • Augmented Info - Viewfinder can show: histogram, levels, eye-AF, focus peaking, clipping etc.

  • True Focus DoF - Permanent DoF preview that shows the correct depth & unaffected by brightness

  • No DoF Limit - No limit to seeing shallow DoF (DSLRs usually limited to f/2.5 due to focus screen)

  • 100% Viewfinder - Large 100% viewfinders are no longer exclusive to the most expensive cameras

  • Crop Lenses - Show just like full frame (zoomed in and 100% coverage)

  • Focus Magnification - Makes manual lenses or checking focus, very fast and accurate

  • No Light Leaking - Viewfinder doesn't need to be covered during long exposures

  • Focus & Speed Unhindered in Live-View - No mirror switching modes and AF systems

  • Shooting Into Bright lights - It is no longer difficult to see, or dangerous to look into the sun

  • Image Review In Sunlight - When you struggle to see the rear screen in sunny conditions, just use the EVF

  • Viewfinder Colour - Showing the world with white balance adjusted colours (full spectrum game-changer)

  • See With Dark / Opaque Filters - Strong ND, IR or UV pass can still show a normal exposure in the viewfinder

  • In-Body Image Stabilization - Most DSLRs don't have IBIS, but if they did you wouldn't see the effects in the viewfinder

  • No Lens Calibration - With focal plane AF calibration for front/back focusing is no longer an issue

  • Adapt DSLR Lenses - Short flange distance means you can adapt to older lenses, sometimes with AF


Sony 200-600mm G - Baby Blue Tit


The A9 was a strong design evolution from Sony's existing full frame mirrorless cameras of 2017 (mkII A7's), bringing features like: A deeper grip, a drive/focus mode dial, multi-selector, touch screen, improved buttons, dual memory cards, better build and a significantly improved battery. Although this distinction didn't last long (the mkIII A7's taking everything accept the mode dial), what really set the A9 apart was speed.

Silent Benefits

The world's first stacked sensor brought two fundamentally game-changing features. A very high scan speed (1/160th), allowing the fully silent electronic shutter to be used without concern of rolling shutter. As well as being great for weddings, sports and wildlife, this increases battery life and reduces mechanical wear, dramatically improving the lifespan of the camera.


Viewfinder blackout is the next big benefit. Many mirrorless cameras mask slow responsiveness by displaying the last image, while it gets ready to take a new one. This gives the impression of zero blackout, until you move the camera, resulting in a laggy/stuttery view. The A9's live view is completely unhindered by shooting so you (and the camera's AF system) never lose track of your subject. This is such a bizarre sensation that the camera has a choice of fake sounds and/or flashing graphics to give you some indication that the camera has actually taken a shot.

All this might sound like a gimmick until you try shooting wildlife, sporting events, or weddings. These things are truly game-chaging in the real-world, much harder to market on paper, but once you have eperienced them you won't ever want to go back!

Build Quality

Despite not being much bigger or heavier than the A7 (mkII's), the A9 was a step up in build quality, ruggedness and weather resistance. Even with a 2Kg+ lens attached holding just the camera feels confidently solid.

A9 Chassis.jpg

An Exploded Diagram of the A9's Magnesium Chassis

I am thankful that the A9 kept the smaller form factor of the A7 range. You can always add a vertical grip for extra battery life and easier portrait shooting if desired, but this makes it much easier for me to carry every day than a pro DSLR. The more compact design also offers a halfway option with a grip purely for the pinky, extending only the grip side if you don't want the extra weight of the full vertical grip. It doesn't allow for tripod use or battery removal while attached and could be more sculpted (to stop your finger from slipping off), but I'll take this over a non-removable battery grip any day!


The top burst speed of 20 frames per second (fps) is pretty amazing for action photography! Although it's worth noting not all Sony lenses allow this speed, some top out at 15fps (click here for a full list). Also 3rd party lenses seem to be artificially capped to 15fps, allegedly due to inferior focus mechanisms, but that's still a decent speed. Word on adapted lenses varies from between 5-15fps, depending on which adapter. lens, firmware, aperture and focus mode you use.

Another thing that limits the full burst speed is uncompressed RAW. Using this will drop the speed to 12fps. It's worth noting that unlike the A9II, using uncompressed RAW is still limited to 12bit during burst shooting. This might seem like quite a few restrictions on the A9's advertised 20fps, but it's not bad compared to the current competition. Even the 30fps Sony A1 won't give you faster burst speeds than 15fps on 3rd party, adapted or slower Sony lenses.


At full speed (20fps) the buffer allows for just over twelve seconds of continuous shooting. Even five years on this is pretty incredible. I have never needed all of it and I can't think that I ever will. It produces an absolute ton of images to look through in post. For your own sanity I don't recommend using it just because you can, but it's nice to know the option is available for the most tricky situations!


Even with fast cards buffer clearing will be pretty slow however, but given that most will want the two cards to be writing the same thing (redundancy) it's a shame that only one of the readers is the faster UHS-II speed, so you will be limited to the slower one. This is most frustrating when shooting a burst of stills and then wanting to record a video, because you will just have to wait for the whole buffer to clear first. The menu system is also locked out when the buffer is clearing, although that's much less of an issue.


Sony 135mm f/1.8 GM - Greater Spotted Woodpecker (male)


The standout focus feature for me here is tracking. Working across a thousand focus points & almost the entire frame, it can be used in combination with Eye-AF and in that mode it has totally transformed the way I shoot. Even with fast & erratic subjects it allows me to concentrate on composition &/or settings. I just tell it where to start and am confident that it'll take care of focus 95% of the time.

Although eye-AF unfortunately doesn't work in video here, touch to focus (using the rear screen) does. The general speed and accuracy of the focusing is lightyears ahead of the A7RII, even beating out the the newer A7IIl by a big margin due to a slower reaction speed and there being no tracking on the A7III. Amazingly this ability extends to adapted lenses as well. Eye-AF has settings for humans and animals, the latter being less reliable and not covering a wide range of creatures, but it's still pretty great.


The amount of customization on the A9 is pretty amazing. Organizing that through the menus is not as nice compared to the most modern Sony's (like the A1), but it's much better than it used to be! Almost everything that I wanted to customize here could be done and there are way more custom buttons to map things to here as well. 11 buttons can be customized with 72 functions. The physical drive/focus mode dial helps here too, as those common functions are more clear and not required to be mapped somewhere else. 

12bit vs 14bit

There seems to be some confusion about when the A9 can shoot 14bit images. Many reviewers claim that the electronic shutter or compressed RAW cause the camera to drop down to 12bit, but this is not true. You can actually shoot both silent and compressed together while retaining 14bit RAW files, just as long as it's in single shot mode. Any speed of continuous shooting (burst) will cause the camera to drop to 12bit. I was initially reluctant to use the burst speeds because of this, instead relying on pressing the shutter as fast as I needed, but when I have used burst I have not seen any huge reductions in dynamic range.


Sigma DG 135mm f/1.8 Art - Swedish Military

Battery Life

Mirrorless cameras may never match the battery life of pro DSLRs on paper, due to their smaller batteries and always active sensor, screens and image stabilization, but there are many other caveats that make a straight comparison difficult too. I have been extremely impressed by the battery life on the Sony A9, perhaps due to my exclusive use of the electronic shutter and religiously turning the camera off when not using it (due to a faster start-up). I get better battery life from the A9 than I did with the A7III, despite the figures suggesting the opposite (650 vs 710 CIPA) and it even out-performs some DSLRs too...


I recently shot almost 2,000 images (+ 3 short videos), using a mix of EVF and rear screen, over a 3 hour period, in -10°c weather and the camera displayed 81% battery remaining! This is a second hand battery that I have owned for a year. By comparison; The Sony A7II camera (using the NP-FW50 battery) has died on me in only a few minutes at -3°c, capturing less than a hundred images for a timelapse. This new Z type battery says it's 2.2x more capacity, but in my experience the life can far out-perform that. The A9 has actually beaten my pro DSLRs on battery life and if you factor in only using the rear screen on the DSLR then the A9 will win by a much bigger margin.


Sony's full frame mirrorless E-Mount cameras have access to nearly 50 native autofocus lenses. That number more than doubles when you take 3rd party native AF lenses into account and that's without counting bulky options like Sigma's pre-adapted SLR Art range. There's also a ton of native manual focus lenses, a massive amount of adaptable autofocus lenses and a metric ton of cheap old manual glass from SLRs, rangefinder and even medium format systems. Sony's five year head start in the mirrorless realm and open source mount has made it a powerhouse of options for any budget.

The A9 launched with one professional tele prime lens, the 400mm f/2.8. Over 4 years on we now only have one more, the 600mm f/4. Although there are also great budget options like the Sony 200-600mm lens it feels like Sony is really lacking in the professional tele lens department. With famous lenses like the 200mm f/2 & 300mm f/2.8 still painfully missing, no built in tele-converter lenses and no compact tele lenses; Sony (with it's least comfortable grip) is now by far the hardest to recommend in the professional segment. Most disappointingly Sony do not provide any lens road-maps, so we can only guess if and when the situation might improve.

EF Sigma DG 135mm f/1.8 Art lens + MC-11 Adapter

Using a Canon EF mount Sigma DG 135mm f/1.8 ART with Sigma's own MC-11 adapter is interesting as it focuses faster and more accurately than my Nikon lenses did on one of their pro DSLRs. That's an incredible sign of how far the focusing has come on modern Sony cameras! This lens is a little heavier than Sony's GM version, but every bit the world class image quality and for much less money. A couple savings like that can pay for a second hand A9, which just blows my mind!


Sigma DN 85mm f/1.4 - The First DSLR (Nikon D1)

I own and like several Sony & Zeiss lenses, but they "mostly" seem a bit overpriced for what they are. looking back on my collection I am most impressed by the modern Sigma lenses (mirrorless / DN). The Sigma DG DN 85mm f/1.4 ART stands out as an amazing portrait lens! I used this to take many of my nature images, product photography (above) and all of the bokeh panoramas (at the end of this review). This lens is a nicer option than the Sony GM in my opinion as it has all the same controls and buttons, but adds an extremely useful aperture lock. It matches or beats the optical quality, firmly beating it on focus speed / noise, has a nicer hood, the build quality is top notch, while being smaller, lighter and cheaper.


I am starting to shoot more video, but it's still not something I am massively into, so other people will have better opinions on this than me. It's clear that the focus of this camera has been stills and not video. Not being able to start shooting a video until even a few images clear the buffer is the only thing I find super annoying. I am happy that it has a full frame 4k/30 and a 1080p/120 mode for when I need to shoot something, as my old A7 had neither of these. The lack of colour profiles, 4:2:2 or 10bit don't really bug me, although it would have been nicer to have them it's not something that would put me off recommending this camera. Maybe the lack of eye-AF in video is the second most annoying thing, but I guess there has to be some reason to buy the A9II :P.


For me the A9 is an amazing choice (especially given the 2nd hand prices), but there's no such thing as a perfect camera and for some people it will be the wrong balance of features or just too expensive for what it offers. Here's a list of all the potential down sides that I can think of:

  • Not the most ergonomic grip (subjective, not related to size)

  • Weather sealing not quite on par with pro DSLRs

  • Gap for fingers can be tight with gloves on some lenses

  • Eye-AF does not work in video

  • Silent mode (electronic shutter) does not work with flash

  • Banding in some artificial lighting can occur (although improved over earlier A7 models)

  • Banding can occur in strong sunlight from the PDAF sensor array (although quite rare and subtle)

  • LCD resolution is a bit low

  • EVF resolution is a little average these days

  • Touch screen only works for focus placement (not menus)

  • Clearing the buffer locks you out from starting a video

  • 3rd party lenses artificially locked to 15fps max burst

  • Burst shooting drops RAW depth to 12bit (small issue)

  • No colour profiles for video

  • No lossless RAW option (not a big deal IMO)

  • No flash (most won't care about this)

  • No voice memo (most won't care about this)

  • Lack of software features (pano, high res sensor shift etc.)

  • Uncompressed RAW drops speed to 12fps max (compressed is fine IMO)

  • Sony's lack of a lens roadmaps (pro tele prime lenses lacking)


Unless you shoot a lot of problematic indoor lighting or video, the A9 is still a superb camera today! I managed to pick up a used one in mint condition, with less than a thousand actuations and a spare Sony battery for less than €1,500. Now that the A9III has been announced I've seen it for less than €1000. if you shoot wildlife, fast action and/or just like to shoot silently without the rolling shutter issue the used A9 prices make it a crazy bargain IMO.


Compared to the best professional DSLRs ever made the A9 is superior in almost every way, while being half the size, weight and cost. Battery life sometimes beats some pro DLSRs despite the always on screens, sensor, continuous AF tracking and image stabilization. That blows my mind! Autofocus tracking & eye-AF may have been improved a little since, but not a lot and the A9 even boosts adapted lens AF too. If you're coming from an earlier A7 it will blow you away.


Even for wildlife photography I would be happy with 10fps for 6 seconds most of the time, but being able to do twice as much for twice as long inspires a lot of confidence. Again, things have improved a bit in the five years since, but not in a big way. Looking back on the market now it feels like the A9 was way ahead of its time. The battery life, autofocus, zero blackout and reliable silent shooting are superb! The cons for most people are few and far between.

The Sony A9 is arguably an even more disruptive technology than Nikon's first purpose built D1 was when it marked the death of Kodak (at the turn of the millennium) and film based digital cameras. Even if the costly transition to newer lens systems will slow down Mirrorless adoption and thus the DSLR's demise it's already possible to see it happening.

Bonus - Bokeh Panoramas

This is a technique that involves stitching multiple shallow depth of field images together from longer lenses to emulate impossibly fast wide angle lenses (go here for more info). I started shooting this technique on the Nikon D3 (2009) with the Nikkor AF-D 85mm f/1.4 lens. Switching to the Sony A7 (in 2014) was a big help for aligning the frames due to the rear screen, but the A9 has a few nice additions that make this technique an even nicer experience. Here is an example of how the images are combined using auotmated software (in this case - Microsoft ICE):


Using the electronic shutter meant that I was no longer concerned about how many images I needed to shoot. A single bokeh pano can be made up from over 100 images. The lack of rolling shutter on the A9 meant I don't get broken or failed stitches from geometry issues resulting from a fast handheld panning motion. Another nice benefit is that the A9 can shoot up to 1/32000th with the electronic shutter (2 stops higher than a pro DSLR). This is very useful in bright conditions when shooting fast lenses, wide open and not wanting to blow out highlights.

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