Canon Speedlite 430EX II and Canon Speedlite 580EX II flashes are the two best flash units Canon created so far. The 430EX II flash is a little brother of the Speedlite 580EX II. It lacks several features but delivers a very good package in a compact body at a lower price. It is significantly smaller and lighter, which can be important to the consumer level users. Also some people are very pleased with having an option of not paying extra for all those fancy features of the Canon 580EX II that they don't need for their applications anyway. But, of course, if you want to get the most powerful flashgun, which is also loaded with everything or almost everything invented so far, then the Canon 580EX II is the way to go.
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One of big advantages of 580EX II is the output power. It can reach 35% farther than 430EX II can (58 meters vs. 43 meters), which makes it 82% more powerful than 430EX II. And when it comes to diffusing, bouncing or reaching far away the more power you have the better. However, Canon 430EX II can be sufficient for a wide range of applications.
Canon Speedlite 580EX II is bigger and heavier than the 430EX II unit. With the batteries installed it weights about a pound.
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580EX II model is weather sealed. This includes flash head, battery compartment door, mounting foot and the body itself. Weather sealing can be critical for some professional applications. Hobbyists won't really miss it in the majority of situations.
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For complete weather sealing, though, you have to use compatible camera body so that the shoe is also sealed when the flash is mounted.
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Flash head on 580EX II turns 180 degrees to the left and right. 430EX II can go from 180 degrees to the left to 90 degrees to the right. This is not a major limitation, but can be annoying.
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Like on many other flash units Canon Speedlite 580EX II head tilts from -7 to 90 degrees. Canon 430EX II head only goes from horizontal to vertical position. The -7 degrees setting can be useful for close-up shots, but 430EX II does not have that.
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Canon Speedlite 430EX II does not have a built-in bounce card (catchlight card). It is not a major loss, but, again, can be handy if you don't have any better light modifier available.
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580EX II can serve as a wireless transmitter and be a master in a wireless setup. It can trigger other Canon compatible units, set the output ratio between all of them, etc.
Canon 430EX II can be triggered remotely, but cannot control other flashes.
Controls are another significant difference between these two units. Buttons on the Canon Speedlite 580EX II have a better tactile feeling. They are not to be pushed as deep as on Canon 430EX II (Please refer to Canon Speedlite 430EX II review for the buttons action issue).
Speedlite 580EX II also offers select dial ("the wheel") as opposed to "+" and "-" buttons of 430EX II. This is, without a doubt, the big step up in the ergonomics. Select dial makes it easy and convenient to select and change most of the flash settings.
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Canon 580EX II features receive only PC connector, which is essential for use with radio slaves. Radio slaves can be used with 430EX II as well, but that requires a shoe adapter to be purchased separately.
Being a professional unit, Canon 580EX II offers a socket to connect external battery pack. For non-professional use this is not a "must have" feature.
Both units have a bracket fitting on the left side of the body. This allows them being mounted on Canon proprietary flash brackets.
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Speedlite 580EX II is the only Canon flash that features external metering sensor. The unit can be used in so-called "auto mode" when it does not rely on camera measurements and calculates it's output independently using the sensor. This can be a big help if your application requires eliminating of the pre-flash, which is always fired in the "through-lens" modes.
Canon 580EX II has a better designed battery compartment door, which has a latch and is supported by a spring when opened. And as we already mentioned the door is weather sealed.
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There are six extra custom functions that are present in the 580EX II unit:
| C.Fn-03 | FEB auto cancel |
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| C.Fn-04 | FEB sequence |
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| C.Fn-05 | Flash metering mode |
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| C.Fn-06 | Quickflash with continuous shot |
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| C.Fn-12 | Flash recycle with external power source |
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| C.Fn-13 | Flash exposure metering setting |
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Canon Speedlite 430EX II, in turn, also has one custom function that Canon 580EX II lacks:
| C.Fn-14 | Flash range/aperture info |
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