If you don't understand bounce flash, you're in good company. Most of the folks I see shooting around New York don't seem to understand flash photography at all, much less the benefits of bounce and how to do it right.
Canon wants to make flash more approachable, starting with the biggest problems. It wants you to be able to easily use it without creating ugly hotspots, harsh shadows or uneven exposures. You know, the main reasons people don't like to use a flash.
simply means reflecting the light off a nearby surface, which (depending upon the surface texture) diffuses it so it falls more evenly and softly on the subject. Finding the right angle takes experience as well as trial and error, as well as manually rotating the head if you switch between vertical and horizontal.
The company's new SpeedLite 470EX-AI offers two modes: a full and a partial "autointelligent" Bounce mode. (No, in this case "AI" doesn't stand for "artificial intelligence.") In full AI Bounce mode, a sensor in the flash measures the distance to the ceiling and the distance to the subject, calculates the optimal angle and automatically rotates the head to an appropriate angle. You can force it to recalculate when you move by double tapping the shutter button.
It's really cool.
It has some limitations, though. For instance, you can't bounce off a wall. That's where semi-AI mode comes in: If you know what you're doing, you can set the bounce angle and target manually. Then, as you move the camera around and rotate it, the flash head automatically adjusts to maintain the angle and bounce target you set.
That is amazingly cool.
Why would partial AI Bounce be better than full? Because of the intended vs. the likely owner of the unit. It's big -- almost as big and heavy as the pro Speedlite 600EX II-RT. So right there you've narrowed the potential market to people who are willing to schlep it, and who have a camera big enough to comfortably counterbalance it.
Then there's the price: when it ships in April, it will cost $400 (roughly £285 or AU$510). That's a lot of money for a consumer, and possibly even for a casual prosumer, especially for a unit with a not-inconsiderable schlep factor. In terms of power, its maximum 47GN falls between the Canon 430EX models (max GN43) and the 600EX models (max 60GN). The 430EX II costs $100 less.
On top of all that, the 470EX-AI still looks as intimidating as any other pro-level flash.
If you shoot regularly and own a prosumer Canon DSLR like the, it's not that much of a stretch. Once you've figured out how the whole bounce thing works, the automation that's helpful when you're starting out can become more of a hindrance. But being able to set the target and angle and forget it frees up a hand -- not having to release the camera to change the angle and rotate keeps it much steadier. (I photograph cats for adoption, which requires every free hand I have to keep them from leaping out of the cage to freedom.)
It also doesn't measure the color of the surface it's bouncing off, so being able to manually target it reduces the potential for color casts.
Even if you don't own a Canon, you can probably make it work with another brand. You might have to manually set the exposure parameters because of incompatible signals, but as far as I can tell, none of the information related to the bounce system comes from the camera. It's all in the flash.
I also have to admit, it was nice to see something wow-worthy from Canon. After spending so long playing catch-up over the past few years, the 470EX-AI shows a welcome spark of useful innovation.