Sony A9 Performance


Timing and Performance

Phenomenal burst speeds and buffer depths, though buffer clearing is incredibly slow for JPEGs.

Startup/Play to Record

Power on
to first shot

~1.2 seconds

Time it takes to turn on and capture a shot.

Play to Record,
first shot

~1.0 second

Time until first shot is captured.

The Sony A9's startup time (power on to first shot) was relatively fast for a mirrorless camera, but sluggish compared to most DSLRs. Switching from Play to Record mode and taking a shot was just a bit faster.


Shutter Response (Lag Time)
Mechanical Shutter (EFCS On/Off)

Full Autofocus,
Center AF area
AF-S mode

0.216 / 0.355 second

Time from fully pressing shutter button to image capture, with the lens already at the proper focal distance setting.

Manual Focus

0.097 / 0.249 second

For most cameras, shutter lag is less in manual focus than autofocus, but usually not as fast as when the camera is "prefocused".

Prefocused

0.020 / 0.165 second

Time to capture, after half-pressing and holding shutter button.

Electronic Shutter

Full Autofocus,
Center AF area
AF-S mode

0.231 second

Time from fully pressing shutter button to image capture, with the lens already at the proper focal distance setting.

Manual Focus

0.119 second

For most cameras, shutter lag is less in manual focus than autofocus, but usually not as fast as when the camera is "prefocused".

Prefocused

0.038 second

Time to capture, after half-pressing and holding shutter button.

The Sony A9's full-autofocus shutter lag (with the subject at a fixed distance) was good although not exceptional, measuring in at 0.216 second in Single-area (Center) AF mode with the Sony Zeiss 35mm f/2.8 lens. This was with the mechanical shutter and electronic first curtain shutter (EFCS) enabled by default. With EFCS disabled, full AF shutter lag increased to 0.355 second. With the fully electronic shutter, full AF shutter lag was 0.231 second, a little slower than with EFCS.

When manually focused, the Sony A9's shutter lag dropped to 0.097 second with EFCS, or 0.249 second without. With the fully electronic shutter, manual focus shutter lag was 0.119 second.

The Sony A9's prefocused shutter lag was only 0.020 second with EFCS, which is very fast. Without EFCS, prefocused shutter lag increased dramatically 0.165 second, but with the fully electronic shutter, it was only 0.038 second.

To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance.


Cycle Time (shot to shot)

Single Shot mode
Large/ Extra Fine JPEG

< 0.3 second
(All shutter modes)

Time per shot, averaged over a few frames (we no longer test for buffer depths in single-shot mode).

Single Shot mode
RAW + L/F JPEG

< 0.3 second
(All shutter modes)

Time per shot, averaged over a few frames (we no longer test for buffer depths in single-shot mode).

Early shutter
penalty?

No
(All shutter modes)

Some cameras don't snap another shot if you release and press the shutter too quickly in Single Shot mode, making "No" the preferred answer.

Mechanical Shutter

Continuous Hi
Large/Extra Fine JPEG

0.20 second
(4.99 fps);
553 frames
254 seconds to clear*

Time per shot, averaged over 553 frames, then slowed to 0.69s or 1.44 fps when buffer was full.

Continuous Hi
Compressed RAW

0.20 second
(4.99 fps);
Unlimited (?) frames;
5 seconds to clear*

Time per shot averaged over ~535 frames with no apparent limit.

Continuous Hi
Compressed RAW + L/F JPEG

0.20 second
(5.00 fps);
Unlimited (?) frames;
66 seconds to clear*

Time per shot averaged over ~340 frames with no apparent limit.

Continuous Hi
Uncompressed RAW

0.20 second
(5.00 fps);
241 frames total;
38 seconds to clear*

Time per shot, averaged over 241 frames, then slowed to an average of about 0.45s or 2.22 fps when buffer was full with a lot of variation.

Continuous Hi
Uncompressed RAW + L/F JPEG

0.20 second
(4.99 fps);
181 frames total;
48 seconds to clear*

Time per shot, averaged over buffer length of 181 frames, then slowed to an average of 0.49s or 2.05 fps when buffer was full with a lot of variation.

Electronic Shutter

Continuous Hi
Large/Extra Fine JPEG

0.05 second
(20.00 fps);
364 frames total;
236 seconds to clear*

Time per shot, averaged over 364 frames, then slowed to an average of about 0.08s or 12.68 fps when buffer was full with a lot of variation.

Continuous Hi
Compressed RAW

0.05 second
(20.00 fps);
240 frames total;
45 seconds to clear*

Time per shot, averaged over 240 frames, then slowed to an average of about 0.29s or 3.40 fps when buffer was full with a lot of variation.

Continuous Hi
Compressed RAW + L/F JPEG

0.05 second
(20.00 fps);
225 frames total;
87 seconds to clear*

Time per shot, averaged over 225 frames, then slowed to an average of about 0.40s or 2.50 fps when buffer was full with a lot of variation.

Continuous Hi
Uncompressed RAW

0.08 second
(11.98 fps);
126 frames total;
36 seconds to clear*

Time per shot, averaged over 126 frames, then slowed to an average of about 0.41s or 2.46 fps when buffer was full with a lot of variation.

Continuous Hi
Uncompressed RAW + L/F JPEG

0.08 second
(11.98 fps);
116 frames total;
46 seconds to clear*

Time per shot, averaged over buffer length of 116 frames, then slowed to an average of 0.48s or 2.10 fps when buffer was full with a lot of variation.

*Note: Buffer clearing times measured with a 64GB Lexar Pro 2000x UHS-II SDXC card. Slower cards will produce correspondingly slower clearing times. Slow cards may also limit length of bursts in continuous mode. ISO sensitivity and noise reduction settings can also affect cycle times and burst mode performance.

Single-shot cycle times were very fast, at less than 0.3 second for both Large/Extra Fine JPEGs and RAW + Large/Fine JPEG frames, regardless of shutter type. (Note that we no longer test single-shot mode with just RAW files, as the results are usually somewhere in between JPEG and RAW+JPEG modes. Also note that the A9 cannot capture highest quality "Extra Fine" JPEGs together with RAW, dropping to "Fine" quality JPEGs when shooting RAW+JPEG.)

Incidentally, we have confirmed single-shot uncompressed RAW files are indeed 14 bits, even with the electronic shutter, however the A9's lossy compression reduces the effective bit depth to 13 bits in single-shot mode in addition to being delta-encoded.

With the mechanical shutter, the Sony A9's top burst speed is a claimed 5 frames per second no matter the file type, and we were able to confirm that in the lab. With the electronic shutter, the top burst speed is 20 frames per second for JPEGs, compressed RAW or compressed RAW+JPEG files, which we also confirmed in our tests. When shooting uncompressed RAW files, the top burst speed dropped to about 12 frames per second, as advertised. We have also determined that all continuous mode RAW files are 12 bits, whether compressed or uncompressed.

Buffer depths were excellent, ranging from a minimum of 116 uncompressed RAW+JPEG files at 12 frames per second in the worst case to unlimited frames (limited only by the capacity of the card) when shooting compressed RAW at 5 fps with the mechanical shutter. At the top speed of 20 fps, the Sony A9 was able to shoot 364 JPEGs, 240 compressed RAW or 225 compressed RAW+JPEG files before slowing, which is within a couple frames of their specs.

Unfortunately, even with one of the fastest UHS-II cards on the market (a Lexar Pro 2000x UHS-II SDXC card) installed in the one slot that supports UHS-II, clearing the buffer can take a long time, particularly with JPEG files. The worst-case buffer clearing time in our tests was a glacial 254 seconds or over 4.2 minutes after shooting a max-length burst of best quality JPEGs at 5 fps, which fell slightly to 236 seconds after shooting 364 JPEGs at 20 fps. Buffer clearing was faster when shooting RAW files, but could still take well over half a minute for long bursts. (It appears the A9 is doing some JPEG processing while it writes them to the card as RAW files are written to the card roughly 4 to 5x faster than JPEGs by our estimation.) Only when shooting compressed RAW at 5 fps was the camera able to clear its buffer in near real-time, essentially keeping up with the capture rate. The Sony A9 does let you change some settings and view just-shot images while the buffer is clearing, however access to the menu system is unavailable.


Bottom line, the Sony A9 is capable of some astonishing performance with up to a class-leading 20 fps burst speed with very deep buffers, however there are some caveats to consider including slow buffer clearing (particularly with JPEG files which are favored by many pro sports shooters), menu lockout during clearing, and needing to use e-shutter and compressed RAW to attain that speed. Power-on to first shot was a bit sluggish compared to a DSLR, though, and while single-shot AF speeds were good, they were nothing to write home about. Shutter lag with EFCS or e-shutter was however very low and cycle times were incredibly fast.

Battery

Battery Life
Good battery life for a mirrorless camera.

Operating Mode Battery Life
Still Capture,
(EVF, CIPA standard)
480 shots
Still Capture,
(LCD Monitor CIPA standard)
650 shots

The Sony A9 uses a custom NP-FZ100 rechargeable lithium-ion battery pack for power, and comes with a single battery, a dedicated battery charger and an AC adapter for in-camera charging via USB. While CIPA-rated battery life is well above average for a mirrorless camera, it's still well below most prosumer and pro DSLRs when using their optical viewfinders. We recommend purchasing a second battery and consider getting the optional VG-C3EM portrait battery grip which doubles battery life with a second battery installed.

The table above shows the number of shots the camera is capable of (on a fully-charged rechargeable battery), based on CIPA battery-life and/or manufacturer standard test conditions.

(Interested readers can find an English translation of the CIPA DC-002 standards document here. (180K PDF document))

 



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