Canon Flash Photography with Rudy Winston
Rudy Winston recently gave a presentation at the B&H Event Space on the popular Canon Speedlite Flash system. BHInsights tracked him down and was able to pick his brain a bit more about using the Canon Speedlite system for consumers.
Chris: Please tell us about some of the flash options that Canon offers to consumers.
Rudy: Current Canon speedlites are all "EX" series flashes. EX in the model name means that the flash is E-TTL compatible, and thus will provide proper TTL-type flash automation with digital as well as film SLRs. (Older "EZ" or "E"-series speedlites can't be used for TTL automatic exposure with digital SLRs, for technical reasons.) There are a full series of speedlites today:
Speedlite 270EX: A very portable, lightweight unit with some bounce capability; a worthwhile step beyond built-in flash for EOS and certain PowerShot models, like the G-series.
Speedlite 430EX II: Larger, more powerful flash, aimed at the serious amateur user—can be used either on-camera, or as an off-camera slave unit for Wireless E-TTL. It features full bounce/swivel capability, covers lenses as wide as 14mm (on a full-frame camera) via its pull-out wide diffuser.
Speedlite 580EX II: Top-of-the-line Canon speedlite, for all EOS models (film or digital) as well as PowerShots with a hot shoe on the camera. About a stop more power than 430EX II, wider range of features, and can be used for Wireless E-TTL as either an off-camera "slave" unit, or on-camera as a "master" unit to trigger off-camera flashes. Also, it accepts optional higher-voltage battery packs.
Macro Ring Lite MR-14EX: A circular-shaped Ring Lite, for macro flash use—attaches directly to most Canon macro lenses (an adapter ring is needed for attachment to front of the EF 100mm F/2.8L IS macro lens, and the EF 180mm F/3.5L macro), and allows varying output between the left and right halves of the ring with ratio control, operated from the shoe-mounted control unit. Can also act as a "master" unit and trigger off-camera flashes for background lighting, accent light, and so on. Like all ring lights, gives a very flat, even character to lighting which, in extreme close-ups, can to some degree be varied with afore-mentioned ratio control.
Macro Twin Lite MT-24EX: Another flash for macro work, but with two moveable AND removable flash heads that allow a very directional quality to macro lighting—easy to simulate sunlight, for instance, with a single head held above a subject. As with MR-14EX, its front ring attaches directly to all Canon macro lenses, except the new 100mm f/2.8L IS and 180mm (an adapter ring is required for these, because of the larger front section size on the lenses). Also, it can be used for wireless E-TTL, as a triggering device for one or more off-camera "slave units".
Chris: With cameras like the 7D and 60D, Canon has recently taken a big step forward with wireless flash control in-camera. What are some common reasons why a consumer would use wireless flash control?
Rudy: The big thing is simply changing the "look" of the lighting, and thus the photograph. Direct flash usually tends to give a very harsh, sort of snapshot quality to pictures, when flash is camera-mounted. By moving a single flash off-camera, we suddenly can create more natural shadows on a subject, and it makes bouncing flash off of ceilings, walls and so on much more practical. Wireless flash—once the user understands a few basics—can totally change the way a user shoots pictures indoors or in low-light situations, and opens the door to moving his/her images to a higher level.
Chris: Tell us about how the E-TTL system works.
Rudy: Two keys—first is the "TTL" part: The camera is always reading flash Through The Lens This has huge benefits: The camera is always seeing what the lens is seeing. Whether you're shooting with an ultra-wide angle lens, or switch to a 400mm telephoto, flash exposure is calculated by seeing the same subject that the sensor will see. It becomes even more important when shooting close-up images, an area of photography that until the advent of TTL flash systems required very complex exposure correction calculations and limited its use to the truly dedicated and/or experienced.
E-TTL works by firing a PRE-FLASH, and using the exact same sensor that's used to meter ambient light, an instant before the picture is taken. The camera reads light reflected back to it from a single pre-flash, calculates what the flash exposure SHOULD be, and almost instantly sends this info to the flash unit. In less than 1/10th of a second, the mirror rises, the shutter opens, and the flash fires a SECOND time, now at the output level it just calculated an instant before, and the subject is illuminated. The shutter then closes, and the exposure ends.
E-TTL works the same way, whether we're talking about a single flash on-camera, or with Wireless E-TTL. The only issue for the latter is that there now is a sequence of back-and-forth communication with pre-flashes between the so-called "master" flash and the off-camera "slave" units, done with sort of a sophisticated "morse code" of multiple, low-power pre-flashes. When you've got just a single flash on-camera, there's only one single pre-flash, as described above.
E-TTL brings with it some cool features, most of which are fully available for Wireless E-TTL as well:
- 2nd-curtain sync, where flash will fire at the END of a long exposure, instead of at the beginning
- Flash Exposure Lock (FEL), which allows user to take a SPOT meter reading of a pre-flash, lock it into memory for 16 seconds or longer, so they can re-compose and shoot. Think of the benefits of traditional spot metering with natural ambient light; the concept is essentially similar here, except that it applies to flash illumination. (Normally, E-TTL flash is performed by initially reading pretty much the whole picture area regardless of what metering pattern happens to be set on the camera body.)
- Hi-speed flash sync, where the flash and camera team-up to allow flash at shutter speeds up to the camera's maximum -- 1/8000th on cameras like an EOS 60D, 7D and so on. Flash remains fully E-TTL automatic, and you can even do this with Wireless E-TTL. (One exception: It can't be triggered for Wireless with the built-in flash of an EOS 60D or 7D if you want Hi-speed sync.) HS sync also isn't possible with PowerShot models having E-TTL speedlite capability, for technical reasons.
Chris: Are there any popular flash modifiers that you’d recommend?
Rudy: Pretty broad area here: Maybe the most important thing for users to realize is that they CAN do a lot of modifying with speedlites, sometimes totally changing the character of their lighting. Things as simple as moving a flash off-camera, and shooting it through a translucent shower curtain, can totally change the look of a picture.
Certainly, there are popular on-flash modifiers like the Lumi-Quest bounce devices, Gary Fong diffusers, and similar ones. These will take a bit of the "bite" out of harsh, on-camera flash, but customers have to remember that they're really only effective when you're close to a subject (realistically no more than 6-8 feet away), and that in diffusing/scattering the light, they do reduce a flash's power. They're almost useless and actually detrimental in situations like a large group photo, where a shooter may be 30 feet or more from his/her subject, and needs as much flash power as can be mustered.
Rudy: The PowerShot models with an accessory shoe accept any EX-series speedlite (including older, discontinued units—as long as "EX" is in the model name), and, for the most part, allow E-TTL and even wireless E-TTL in similar fashion to an EOS SLR. The one area I can think of where they differ from EOS SLRs is what happens when you put the camera (not the flash) in Manual Exposure Mode. With the PowerShots, this simultaneously puts the flash into its manual flash mode as well. With all EOS SLRs, on the other hand, flash remains completely in E-TTL, giving the shooter a very practical way to mix a fast shutter speed with a moderate aperture for sharp, action-stopping flash pictures in dimly-lit conditions.
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