Canon 550EX Strobist Flash


Being one of the former top grade models in the Canon flash lineup, the 550EX offers a solid build quality and a strong power output. Its manual mode covers a wide range of 8 f-stops. On the downside, there is neither a PC port nor an optical slave sensor, and recycling time is somewhat slow with 8 seconds at full power. Due to these reasons, it is unlikely to turn a Nikon shooter into a Canon flashgun afficionado, but it is an excellent choice within an existing Canon setup. Despite its age the 550 – like all EX series strobes – is also a TTL flash and can be used as master and slave in a modern wireless E-TTL (II) setup, and certainly on-camera too.

Strobist Must-Haves

  • manual mode
    • has manual mode: yes
    • minimum manual power: 1/128
    • all full stops from 1/1 to 1/128: yes
  • X contact firing: yes
  • flash standby mode: no problem (3-way switch)

Verdict: AA


Unlike in many Nikon models, there is no PC synch port and no optical slave sensor built-in – only the flash foot can be used to trigger. And in that scenario there is an incompatibility too: if used with optical slave adapters, e.g. Wein slaves, the flash will fire once and then freeze (that’s at least what frustrated users have been reporting). Luckily, it works just fine with radio slaves (e.g. Cactus V4), which should be the preferred solution anyways. And on top there is a receiver for the wireless E-TTL trigger signal from another Canon flash or the ST-E2 transmitter – another good triggering option, although not the strobist way.

Manual Mode

The manual mode is accessed via pressing the ‘mode’ button. Press ‘sel/set’ and then the ‘+’ and ‘-’ buttons to go from full to 1/128 power in full but not third steps, which means a range of 8 f-stops. Pressing ‘sel/set’ again locks in the value.


The 550EX has a power switch with 3 positions: on, off, and SE = ‘Save Energy’ – perfect solution, and much better than in the successor model 580EX.

Flash Head

The flash head can be tilted from -7 to + 90 degrees and offers the usual 270 degrees swivel, but there are two different buttons that need to be pressed for the adjustments. Its manual zoom ranges from 24mm up to 105, and it covers down to 17mm with the built in diffuser. In auto mode and on the camera, the head is zooming with the lens, but unlike newer models it is not able to see if it’s on a full frame or APS-C camera. When it auto-zooms, it does so to the correct position for FF thus always wasting some light for crop cams (but certainly more than covering the whole frame).

Output specifications

550EX has a guide number of 36 at 35mm and ISO100, which means it is one of the stronger units out there. When zoomed out to 105, the GN climbs to 55 – which explains also the model’s name: in the Canon world a model’s name is always the guide number at full zoom x 10. Flash duration is at an uncritical value with 1/1200 seconds at full or less at partial power. With 4 alkaline batteries, the unit needs a long 8 seconds until it is recharged after firing at full power. With one of the 2 external power sources the recycling time goes down to 5 or even 3 seconds respectively. A plus – but only for E-TTL usage – is the FP-synch mode which allows the usage with shutter speeds up to 1/8000 seconds, albeit at greatly reduced range.

Power Supply

Apart from operation with AA batteries, there are external power packs available. Transistor Pack E uses the Canon Battery Magazine TP with 6 C-size batteries or a Ni-Cd Pack TP. The compact Battery Pack CP-E2 requires 6 size-AA alkaline or nickel-hydride batteries. AA lithium batteries can also be taken. If an external power source is used, the internal batteries have still to be installed and are also being used, that’s why the manual recommends to “keep a spare set of batteries handy” for a longer shoot.


Canon’s speedlite 550 was introduced in 1998 together with the EOS-3, well before the DSLR boom began. But it is still today fully compatible with E-TTL and E-TTL II, and it is obviously a very capable strobist flash if used with radio triggers. Compared to newer flashes, it does not support as many AF points for focusing, and recycle time is slower which is maybe the main downside, but the 580EX which was introduced in 2004 has also improved ergonomics.

Full Tech Specs

Model Information
Brand Canon
Model 550EX
First introduction 1998
Successor 580EX
Output Specs
Guide number spec
(35mm, ISO 100, in meters)
Guide number test result ?
Manual power settings 1/1 – 1/2 – 1/4 – 1/8 – 1/16 – 1/32 – 1/64 – 1/128
Flash duration (full power) 1/1200
Recycle time spec
(at full power)
8 sec alkaline
Recycle time test result ?
Flash foot material, type plastic, standard ISO (Canon)
PC Sync Port no
Optical Slave no
Other Trigger wireless TTL slave mode
Trigger Voltage 5 V
Standby Mode no problem (3-way switch)
Flash Head Features
Swivel -180 to +90 degrees
Tilt -7 to +90 degrees
Manual Zoom Head (17) 24 – 105
Auto Zoom (17) 24 – 105
Bounce card / 2nd reflector no / no
LCD Display yes
Power Supply
Batteries Used 4 x AA
External Power Source Battery Pack CP-E2, Transistor Pack E
Nikon TTL
D-TTL na
i-TTL na
CLS Wireless Slave na
CLS Wireless Master na
Canon TTL
E-TTL(II) yes
E-TTL(II) wireless slave yes
E-TTL(II) wireless master yes
Other Flash Modes
Stroboscopic Mode yes
Auto Mode no
TTL Features
AF Assist Light yes
Exposure Compensation in TTL Mode on the Flash unit -3 to +3 EV
Rear Curtain Synchronization yes
High Speed Synchronization yes
Sensor Size Detection (DX, FX, etc) no
Modeling Light no
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2 Responses to Canon 550EX Strobist Flash

  1. Olivier says:


    I have two 550ex for years and I am sure FP sync can be used on Manual mode (1/1,1/2…1/128) and not only in E-TTL as you suggest : “A plus – but only for E-TTL usage – is the FP-synch mode”.
    Maybe you mean that the pulse can not be hand-held meter in a typical manual usage ?


    • Speedlights says:

      Hi Olivier! Thx for the feedback; what I meant is that FP sync can’t be used in pure manual flash mode when used wireless – e.g. with simple radio triggers such as a Yongnuo RF-602. You’re right about the facts that it works in other scenarios in conjunction with manual mode. Thanks!

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