Canon Speedlite 470EX-AI flash

      Photo Review 8.5

      In summary

      The Speedlite 470EX-AI flash could be useful for events and wedding photographers who need to work quickly and often switch between shooting in landscape and portrait orientations.

      The ability of the flash to reposition its head without requiring manual adjustment and/or calculations of the flash output could be a real time-saver and reduce the number of missed shots in rapidly-changing situations.  

      Features like the ability to detect the sensor size of the camera in use and adjust zoom and output accordingly will probably be handy for photographers who use both full-frame and APS-C cameras.

      Note: the full capabilities of the flash (notably the fully automatic AI Bounce mode) work only on cameras built after 2014 – excluding the EOS 2000D, EOS 4000D, 1300D, EOS M6, EOS M5 and EOS M3.  


      Full review

      Artificial Intelligence (AI) is finding its way into all kinds of products these days so it should come as no surprise that it has been (at last) incorporated in an accessory flashgun. Canon’s Speedlite 470EX-AI claims the honour of being first cab off the block with technology that can automatically determine the optimal angle of a flash head using two measurements: the distance between the camera and the ceiling and the distance between the camera and the subject. In theory, this should make novice photographers more willing to use flash. We set out to discover whether that could be true.


      The Canon Speedlite 470EX-AI (Source: Canon.)

      The AI system is the highlight feature of the 470EX-AI. It works by firing a pre-flash pulse at the subject ceiling to measure the camera-to-subject and then tilting upwards to fire a second pulse for the flash-to-bounce surface distance. This data is used to determine the optimum bounce angle and output of the flash.


      This diagram shows how the flash works by firing pre-flashes to measure flash-to-subject and flash-to-bounce surface distances and using the data to determine the angle of the bounce head. (Source: Canon.)

      The review unit was supplied with a Canon EOD 6D Mark II camera since its AI functions weren’t supported by the older Canon DSLRs we own.   Supplied accessories include a diffusion dome, stand and padded soft case. Batteries are not provided.

      Who’s it for?
       The full capabilities of the flash (notably the fully automatic AI Bounce mode) will only work on cameras built after 2014 – excluding the EOS 2000D, EOS 4000D, 1300D, EOS M6, EOS M5 and EOS M3. This means the main reason for buying this flash is irrelevant to photographers who use enthusiast and professional models like the EOS 6D, 5D Mark II and EOS-1D X.   In addition, cameras like the EOS 1300D and Canon’s mirrorless EOS cameras will only support AI bounce in semi-automatic mode.  

      While all future EOS cameras will probably be fully compatible, to make it worthwhile for users of older cameras to invest in the Speedlite 470EX-AI, Canon will need to upgrade the firmware of existing cameras to ensure the integrated AI bounce technology of the 470EX-AI and any future Speedlights is usable.

      Much of Canon’s marketing message for the Speedlite 470EX-AI flash is directed at ‘entry-level and enthusiast photographers’ who have hitherto been intimidated by shooting with flash. By being able to calculate the optimal position and angle for the flash head, it should make shooting with flash easy and effective ““ at least in theory.

      The Speedlite 470EX-AI flash could be useful for events and wedding photographers who need to work quickly and often switch between shooting in landscape and portrait orientations. The ability of the flash to reposition its head without requiring manual adjustment and/or calculations of the flash output could be a real time-saver and reduce the number of missed shots in rapidly-changing situations.


      Sample images provided by Canon to illustrate the Speedlite 470EX-AI’s potential usage. (Source: Canon.)

      The guide number of 47 metres at ISO 100 should be adequate for most of the situations event photographers encounter. However, pricing will probably be an issue for entry-level photographers, since the flash costs more than Canon’s entry-level EOS 1500D, which comes with an EF-S 18-55mm III kit lens. It also lacks the weatherproof sealing of Canon’s more powerful 600EX-RT II flashgun, which is listed in the Canon Store at AU$799 but is considerably more powerful.

      Build and ergonomics
       Like most other mid-range flashguns, the Speedlite 470EX-AI is made mainly of polycarbonate plastic. Build quality is as high as you’d expect from a Canon product. The metal foot that clicks onto the camera’s hot-shoe is nice and solid and it’s locked into place with a lever just above the foot.

      The adjustable head moves freely and can be tilted upwards through 120 degrees and swivelled to the left and right through 180 degrees.  The main body of the flash accommodates the four AA/LR6 batteries, which drive the automated tilt and swivel functions.

      When powered-up, the motorised zoom automatically tracks the focal length of the lens in use. Like most recent Canon flashguns, the 470EX-AI will detect whether it’s on a full-frame or APS-C format camera and adjust the zoom accordingly. The AI system can also sense whether the camera is held vertically or horizontally.  


      This illustration shows the range of vertical adjustments available for the Speedlite 470EX-AI’s bounce head.  (Source: Canon.)



      The Speedlite 470EX-AI will also detect the camera’s orientation and adjust the head accordingly when the camera is in portrait orientation. (Source: Canon.)

      Above the screen is a tiny slider with three settings: 0o, S and F. The first position fixes the flash head in the forward-facing position. The S setting selects the semi-auto mode, while the F setting is for the Full-auto mode.


      This diagram shows the difference between the AI.B Full-auto and AI-B Semi-auto modes. (Source: Canon.)

      In the F (AI-B full-auto) position, the flash will determine the optimal bounce position and output based on the results of the pre-flash distance measurements. This operation must be triggered by pressing either the AI-B button to the left of the arrow pad or the compatible camera’s depth-of-field preview button.

      The Semi-auto mode, enables the photographer to direct the flash head towards the bounce surface and then register the bounce angle by pressing the Angle Set button on the side of the head. This locks the position into the flashgun’s memory. Users can also lock the flash into the correct position by pressing the shutter button twice.
      Aside from the AI system, the 470EX-AI is conventionally designed. Its head has a pull-out diffuser panel which extends the angular spread of the light. A bounce adapter diffuser, which clips on over the head, is supplied with the flash to enable the bounced light to spread across a wider area, thereby reducing potentially harsh shadows.


      The Speedlite-470EX-AI fitted with the bounce adapter diffuser, shown on the EOS 6D-II camera used for this review. (Source: Canon.)

      The rear panel is also conventionally designed, with a monochrome LCD screen plus dial and button controls. During normal shooting, a charge mark appears near the top of the screen, disappearing when the charging has been completed.


      The rear panel of the Speedlite-470EX-AI. (Source: Canon.)

      To the right of the AI.B button lie buttons covering the sub-menu settings and back functions. Adjacent to them is the arrow pad with central SEL/SET button and rotating dial, which lets users set the zoom, exposure level, mode and wireless functions.

      Pressing the SEL/SET   button in the centre of the arrow pad or the mode button at the bottom of the arrow pad selects between full-auto and manual modes. In the former, setting the camera to the P shooting mode enables the use of E-TTL II   or E-TTL   fully automatic flash. The screen will display an ETTL icon to indicate this mode has been selected.

      In this mode, the camera will communicate with the flash providing details of the focal length (shooting angle of view) and sensor size while the flash adjusts the output accordingly. This mode can cover a range of angles of view between 24mm and 105mm. Pulling out the built-in wide panel extends the coverage to 14mm.

      The auto mode can also be used with the Av, Tv and M shooting modes and the camera will set the relevant function to provide the correct flash exposure. Blinking shutter speed or aperture icons indicate over- or under-exposure.

      In the manual mode, the zoom button is used to adjust flash coverage. Two options are available: auto and manual. To set the flash coverage manually, users must select the focal length from the range displayed on the screen. (The user manual recommends setting a wider range than you require to avoid peripheral darkening in the subject.).

      Flash output can be set between full output to 1/128th power available in 1/3 step increments. The +/- button is used to adjust flash exposure compensation across a range of +/- three stops in 1/2 or 1/3EV increments. It can only be used in the Creative Zone shooting modes. The FE lock setting locks in the flash exposure.

      The manual mode also allows users to select high-speed sync for shooting moving subjects that require faster shutter speeds and it can handle shutter speeds that exceed the camera’s maximum sync speed. The output of the flash is reduced in this mode. It’s useful for shooting with wide apertures to achieve background blurring in bright outdoor locations.

      Second-curtain sync is also selectable when photographers wish to capture light trails of moving subjects. The flash will fire just before the end of the exposure. When the camera’s depth-of-field preview button is pressed, the flash will fire4 a continuous burst of light for approximately one second, to provide a ‘modelling light’ for checking shadows that will be cast by the flash.

      The built-in infrared light on the front of the main panel shines a steady beam towards the subject, including during bounce shooting. This enables up to 19 of the camera’s AF points to be used for achieving sharp focus.

      When the selected AF point is close to the periphery of the frame, a series of intermittent flashes will be emitted to cover the entire frame. This enables focusing and flash output to be optimised for the subject.

      The 470EX-AI can serve as a receiver unit in an optical wireless flash setup when used with a compatible flash or a Speedlite Transmitter mounted on camera. It can be placed up to 15 metres from the camera in this type of set-up. However, it can only operate as a slave, not a master.   Because it lacks RF (Radio Frequency) communication, you can’t fit it on the camera’s hot-shoe and use it to control other flashguns in slave mode.

       We tested the review unit with both single-use  alkaline and rechargeable NiMH batteries.  With the full power setting, the cycle time for the alkaline batteries ranged between about half a second and just over two seconds, while the NiMH batteries averaged 1.3 seconds, depending on battery status. Switching to half power reduced the cycling times by roughly 50%.

      Canon rates the battery life at between 115 and 800 shots with a set of four alkaline cells, depending on the output power setting and how much you use the motorised bounce/swivel and zoom functions. We found that range to be credible; although we fired the flash roughly 250 times, it wasn’t enough to fully deplete the alkaline batteries.

      We tried the flash out in a number of outdoor and indoor settings and found the auto bounce function wouldn’t work in rooms with eleven foot ceilings (which were common in houses built in the early years of the 20th century) or in situations where there wasn’t a suitable bounce surface. It seems the beam fired towards the ceiling isn’t strong enough to reach that far so all the shots we took had the flash head facing forwards, regardless of the flash or camera setting.
       An example of a situation where there was no suitable bounce surface, which meant the flash head could only be pointed forwards. We had to reduce the flash output by two f-stops to obtain balanced lighting. The flash provided an acceptable balance between a very bright background and relatively poorly-lit foreground.

      We found the ETTL flash metering to be accurate in most situations, both with direct flash and in bounce mode as well as with the wide diffuser panel and the bounce diffusion dome. There was a tendency to over-expose the flash with some close-up subjects (especially those against dark backgrounds) but it was easy to cut back the flash output for better balanced lighting.

      When used as a fill-in flash, the bounce head will rotate to the forward-facing position when it can’t detect a suitable bounce surface, such as when you’re shooting out of doors. To obtain natural-looking results you will probably need to reduce the flash output   by one to two f-stops (depending on the relative brightness of the background).


      An example of flash fill-in with -2EV exposure compensation on a subject against a bright background.

      When the camera was using the Av and P shooting modes, the auto flash tended to favour longish exposures, which could lead to shots being affected by camera shake. Users need to bear this in mind when shooting in poorly-lit areas where the Tv (shutter priority) mode can be used to ensure the minimum exposure is fast enough to prevent camera shake.

      Shots taken in indoor situations were usually successful and the flash was able to over-power artificial lighting and easily covered the angles of view of the 24-70mm lens we used for our tests. Some examples are shown below.


      These two shots compare the effect of using the flash (lower image) with available lighting. Both shots were taken at f/4 with ISO 100 sensitivity and the camera hand-held. However, the available light shot required an exposure of 1/3 second, which resulted in slight camera shake, while the flash shot used 1/60 second. Note the superior lighting balance in the flash exposure.


      Two indoor portraits taken with spot metering at ISO 800, using flash with an exposure of 1/60 second at f/4. No exposure compensation was applied.


      An indoor close-up, taken with the lens set to macro mode. 70mm focal length, ISO 1600, 1/10 second at f/4.

      We were unable to test the Speedlite 470EX-AI’s wireless capabilities due to a lack of a compatible flashgun. The 470EX-AI’s built-in LCD panel displays the flash charge condition almost constantly and, along with the flash-ready lamp makes it easy to see when the flash has recharged.

         While the 470EX-AI is certainly innovative, it’s actually not all that intuitive for novice photographers to use and the printed manual requires a fair bit of studying to work out how to operate the flash’s controls. Beginners may also find it hard to judge the optimal exposure levels in different situations, even when the flash is in full auto mode and more experienced photographers may not find it meets their requirements.

      Features like the ability to detect the sensor size of the camera in use and adjust zoom and output accordingly will probably be handy for photographers who use both full-frame and APS-C cameras. And we suspect the ability to quickly re-set the flash when swapping between portrait and landscape orientation will be useful for event photographers.

      However, we found it required a fair bit of trial and error to work out the capabilities and limitations of the device. It could also be relatively slow to use, taking a second or so for the auto mode to calculate the bounce position and exposure level.

      Subjects could be surprised the first time they encountered the moving head, resulting in expressions that weren’t exactly flattering. (Demonstrate the flash before shooting to prevent this from occurring.)

      Our final reservation is the price of the flash, which at an MSRP of AU$749 is only $50 short of the more powerful, professional quality 600EX II-RT. This is higher than the price Canon is asking for the entry-level EOS 1500D camera with 18-55mm lens so we think entry-level buyers will have some reservations about investing in it.

      Since the Speedlite 470EX-AI was announced in late February, it’s a bit early to expect significant price discounting. Yet already many local online re-sellers have knocked $100 off the Canon shop price. It’s not listed on the Amazon Australia website but both B&H and Adorama have it listed at US$399, which was equivalent to just over AU$525 when this review was published. But we wouldn’t recommend buying this flash sight-unseen since you really need a hands-on trial to ensure it will meet your requirements.



       Guide Number: 47 metres at ISO 100
       Focal length coverage: 24-105mm
       Zoom head: Yes with auto zoom for sensor size
       Coverage with built-in wide panel: 14mm
       Flash modes: E-TTL II, E-TTL, TTL; High speed sync (FP); manual adjustment – 1/1 to 1/128 in 1/3EV steps; FE lock, flash exposure compensation & bracketing, second curtain synch, modelling flash, colour temperature data communication
       Wireless flash: Infra-red transmission; range = 10 m indoors, 6/10m outdoors; receiver for 3 groups, 4 channels
       Flash head movement: Up = 0-120 degrees; left/right = 0-180 degrees; AI Bounce full auto, AI Bounce semi auto
       AF assist: Infra-red / flash strobe beam; supports 1-16 AF points (28mm or longer focal length)
       Weatherproof sealing: No
       Power source: 4 x AA/LR6 batteries
       Max. recycling time: Approx. 5.5 seconds
       Custom functions: 10 (24 options) + 9 personal functions
       Dimensions (W x H x D): 74.6 x 130.4 x 105.1 mm
       Weight (without batteries): 385 grams
       Supplied accessories: SBA-E4 bounce adapter, Speedlite soft case, stand
       Distributor: Canon Australia; 1800 021 167;  



      RRP: AU$749; US$399.99


      • Build: 9.0
      • Ease of use: 8.3
      • Performance: 8.5