Secondcurtain sync

To solve the first-curtain sync problem mentioned above, and to get the light trails looking like they're following behind the moving object as they should, you need to fire the flash right before the shutter closes. This is called second curtain or rear curtain sync flash since the flash is fired about 1.5 milliseconds before the second curtain of the shutter starts to close. The result is a photo which expresses motion nicely - it will show light trails following the moving object. The Canon...

Older Canon Speedlite flash units

Older Canon Speedlite flash units which lack the letter E in their product name were not designed for EOS cameras. There were Speedlite A models (eg 199A) for old Aseries Canons such as the A1 and AE1 and Speedlite T models (eg 277T) for T-series Canons such as the T50 (but not the T90) and various other special-purpose models. You can put these older flashes on your EOS camera and they'll trigger OK when you take a photo, but they can't use modern automated flash metering. So you have to...

The first curtain sync problem

As noted in the section on X-sync, Canon EOS cameras (and basically all SLRs) have two moving curtains in the shutter mechanism. The first curtain opens the shutter and the second curtain closes it. Let's say you take a flash photo of a static object combined with a long shutter speed. Normally the shutter opens, the flash fires, time passes and then the shutter closes. Now let's say you're taking a photo of a moving object. The object is illuminated enough to leave light trails recorded on the...

ETTL evaluative TTL

With the Canon Elan II 50 camera in 1995, Canon introduced another form of flash technology - E-TTL, for evaluative through the lens flash metering. E-TTL fires a low-power preflash of known brightness from the main bulb to determine correct flash exposure. It measures the reflectance of the scene with the preflash, then calculates proper flash output to achieve a midtoned subject, based on that data. It uses a preflash, but doesn't suffer from A-TTL's drawbacks for two reasons. First, the...

Flash Photography with Canon EOS Cameras Part I

The invention and subsequent automation and miniaturization of electronic flash revolutionized photography. If you're a photographer you're no longer tied to available light. A reliable and portable light source is immediately at your disposal if you choose. But flash photography has always been a very difficult technique to master on any camera system. It's easy to take a snapshot of your friends in a restaurant and get that hideously blown-out rabbit-in-the-headlights look from built-in...

Power source options for external flash units

Most Canon external flash units run off four standard AA (LR6) alkaline cells, though one - the tiny and discontinued Canon 160E - used instead a small 2CR5 lithium battery of the type used by many EOS cameras. Here are some power source options for the AA type of flash. Remember that all batteries can leak. If they do you'll find your beloved flash unit full of a corrosive liquid that will damage or even destroy it. It's wise to remove any cells from your flash if you aren't planning on using...

Program P mode flash

The overriding principle of Program (P) mode in flash photography is that the camera tries to set a high shutter speed so that you can hold your camera by hand and not rely on a tripod. If that means the background is dark, so be it. Program mode operates in one of two modes, depending on the ambient (existing) light levels. 1) If ambient light levels are fairly bright (above 13 EV) then P mode assumes you want to fill-flash your foreground subject. It meters for ambient light and uses flash,...

Macro flash

Canon sell three flash units for macro (closeup) photography. Two, the TTL-only ML-3 flash and the E-TTL MR-14EX flash, are ring-shaped flashes designed to fit directly around the end of a macro lens. The other, the luxurious and hugely expensive E-TTL MT-24EX macro twin lite, contains two small flash heads on the end of a pair of short swivelling arms which can be adjusted independently and which can also be clipped to a ring that fits macro lenses. The MT-24EX flash heads can even be detached...

FP focal plane or high speed sync flash mode

Synchronizing flash exposure with both curtains of focal plane shutters was as much of a problem in the days of single-use flash bulbs as it is today with electronic flash units. For that reason flash bulbs designed to work with focal plane shutters were developed. Such bulbs produced light quite rapidly and sustained their light output for the full duration of the shutter opening. They were called FP bulbs. With E-TTL Canon introduced an implementation of an electronic FP flash mode, which is...

Cameraspecific notes on AF assist lights

The EOS 5 A2(E) and 10 10s these older cameras never activate the AF assist lights on external flash units - they will only illuminate the camera body's built-in AF assist light. The reason for this limitation is because the camera bodies have multiple selection points and the flash units sold at the time could not cover all of the points. The 10 10s is also unusual in that its external two focussing sensors look for horizontal lines and not vertical lines, whereas many flash units project only...

TTL through the lens flash metering

As noted above, the earliest electronic flashes required the photographer to perform distance calculations by hand. Later, the first generation of automatic electronic flash units relied upon external sensors to determine the flash exposure setting. These sensors, mounted on the front of the flash unit, simply recorded the flash bulb's light, reflected back from subject, and cut off the power when enough light for a satisfactory exposure was determined. The venerable Vivitar 283 still sold...

Maximum Xsync speed and EOS bodies

These are cameras of the Rebel series in North America (eg Rebel G, Rebel 2000), the Kiss series in Japan (eg EOS Kiss, Kiss III), and the EOS three-digit series (eg EOS 300, 500 but not the EOS 100, 600 series or 750 850) and all EOS four-digit series (eg EOS 1000, 3000) elsewhere. Note, however, that some users report that their Rebel EOS three four-digit cameras are actually physically capable of attaining a 1 125 second X sync. That is, the shutter mechanism...

TTL and ETTL and EOS digital cameras

All current Canon digital cameras with hotshoes - both the D30, D60, 1D and IDs digital EOS cameras and the non-EOS PowerShot Pro 70 IS, Pro 90 IS, G1 and G2 point and shoot digital cameras - support E-TTL only. Even Canon digital cameras with internal popup flashes are E-TTL only. (though if you want to use flash with a non-EOS camera you should probably check out Kevin Bjorke's page for its limitations. Canon have also written a letter to D30 users concerning proper use of EX flash units)...

Slave flashes

Slave flashes are simply self-contained flash units which respond to external triggers of some kind. They're frequently used in studio situations. For example, you might have a multiple-flash setup - one flash to illuminate the subject and another unit or two to illuminate the background separately. Many slave flashes are triggered by light optical slaves. They have small sensors built in or attached that detect the light pulse from another flash unit and then trigger immediately themselves....

External battery packs

Most of Canon's high-end flash units have sockets on the side which can accommodate external high-voltage 270 volts battery packs. These packs have two basic functions - they speed up the flash's recycle time between shots to a second or two critical for news or wedding photography and extend the time you can go between changing batteries. They're also useful in cold weather battery performance always drops precipitately at freezing temperatures since you can stuff the pack inside your jacket...

Type A and type B bodies

Type A bodies, with support for E-TTL flash, FEL and FP mode EOS D2000 digital EOS Rebel G 500N New EOS Kiss EOS Rebel 2000 EOS 300, Kiss III EOS IX, IX 7, IX Lite, IX 50 APS EOS Elan 7 E , EOS 30 33 7 EOS 1V EOS D30 and D60 digital EOS 1D and 1Ds digital EOS 3000N EOS Kiss IIIL EOS 300V Rebel Ti Kiss 5 Type B bodies, with support for TTL and A-TTL only EOS 600 series - 600, 620, 630, 650, RT EOS 700, 750, 800 EOS 1 First generation Rebel series - Rebel, Rebel S, EOS 1000 and all 1000 variants,...

Took a flash photo and the background is pitch black or very dark

In P program mode and all flash-using PIC icon modes except for night mode if your camera has it the camera uses the flash as the primary light source for the foreground subject. If the ambient light levels are low, therefore, the background will turn out very dark. This is because the flash is not illuminating the background and the shutter speed is too short to expose adequately for background areas. Remember that the light from any battery-powered flash...

ATTL advanced TTL

Canon's first step in altering flash exposure design was the creation of A-TTL, or advanced through the lens flash metering, which was introduced with the T90 camera and continued on to the EOS series of film cameras. A-TTL flash units 300TL and EZ series Speedlites only send out a brief burst of light during the metering phase. ie when the shutter release button is pressed halfway This preflash is recorded by an external sensor on the front of the flash and used to determine a reasonable...

Using wireless ETTL

You can specify one of four different data channels for flash control, and each flash unit can be put into one of three groups. The four channels are there so that up to four cameras can use wireless E-TTL in the same physical location without conflicting with each other, and the three groups are there so that independent flash output ratios can be specified though only with certain cameras see below . When wireless mode is used with any type A body you have full E-TTL metering, FP mode, FEL...

Save Energy SE mode

Most EOS flashes go into low-power or SE mode called Energy Conservation Control in some Canon material after a predetermined period of time - usually 90 seconds or 5 minutes - in order to minimize battery drain. Some flash units are always in SE mode when powered on. However, since it can be annoying to have your flash unit turn itself off in the middle of setting up a shot some flash units have a three-position switch - off, on and SE. The ability to override SE mode is very important for...

Av aperture priority mode flash

Av mode lets you set the depth of field by specifying the lens aperture. The camera then chooses a shutter speed ranging from 30 seconds to the camera's X-sync speed, in order to expose the background correctly. If that means the shutter speed is some really low value so that you need to use a tripod to avoid camera-shake blur, so be it. In dark conditions, therefore, Av mode works in slow sync mode. Flash duration flash output is determined by the flash metering system. Like Tv mode the camera...

Fill flash ratios

The fill flash ratio is commonly described in terms of the ratio of ambient light plus fill flash combined, compared to the fill flash alone. Canon EOS gear, however, usually lets you adjust the fill flash in terms of stops of flash output, in either 1 2 or 1 3 stop increments. What's the relationship between the two ways of describing fill flash A ratio of 1 1 would mean that the flash unit is the sole source of light 0 ambient 1 flash and therefore you wouldn't have a fill flash situation. A...

Setting stroboscopic flash

High-end Canon hotshoe flash units have a stroboscopic mode, activated by pressing the mode button until MULTI is displayed on the rear LCD panel. You can then enter the firing frequency in hertz ie the number of flashes per second and the power output setting. The 5xx flashes also let you specify the actual number of stroboscopic light flashes as well. The 4xx flashes don't, so you have to calculate that number from the time period the shutter is kept open and the number of flashes per second...

Existing documentation

Learning more about flash photography with EOS cameras is hard as there's relatively limited information available on the topic. Canon's manuals tend to be fairly short, and not much information has been published about the flash algorithms used by EOS cameras. There's a brochure on the topic - Canon's Flash Work, but unlike the excellent and similarly titled book Lens Work, the flash brochure does not go into much detail. Hove Silver Pixel Press published a book on the Canon Speedlite 540EZ...

Handlemount grip flash

Canon still make one large flash unit of this type, the 480EG. It's basically a flash bracket with a massive heavy-duty flash attached to the side. The camera sits on the bracket and is held in place via the tripod mount. This type of handle flash is sometimes jokingly referred to as a potato masher flash unit. The 480EG is a high-output flash unit meant for press or wedding photographers, but hasn't been updated in some time and is a TTL-only flash no A-TTL or E-TTL support . Nowadays people...

Rapidfire mode

Electronic flashes work by charging up a capacitor with electricity, then releasing the stored-up power in a split-second burst of light. This charging process, the recycle time, takes up to a few seconds on larger units - which can be a problem if you need to take several flash photos in fairly rapid succession, such as at a wedding. Many EOS flashes have the ability to be triggered even if not fully recharged, on the theory that there are times when you're better off being able to take a...

TTL and ATTL flash metering patterns

The flash metering pattern is determined by the type of flash sensors built into the camera. If the camera has only one focussing point then it will have a single zone flash sensor. Flash metering is conducted using this sensor in a centre-weighted averaging pattern. If the camera has multiple focussing points then it will have multiple zones what Canon call their AIM system. The number of flash metering zones depends on the camera model. For instance, the EOS 10 10s has three focussing points...

Trigger circuit voltage

Old flash units - both studio and hotshoe-mount - used pretty high voltages between the camera and the flash - often from 25 to 250 volts. This is because the flash units were fired by simple switches - electrical contacts. Modern cameras, however, rely on electronic circuitry rather than electric switches. This allows for more flexibility and the possibility for computerization, but the circuits can't withstand high trigger circuit voltages anything above 6 volts, in the case of EOS cameras,...

Auto fill reduction

Also called automatic reduction of flash output in some Canon documentation. Canon EOS cameras automatically use regular flash exposure with no compensation when ambient light levels are low - 10 EV or lower. However, when ambient light levels are brighter - 13 EV or higher - the camera will switch to fill flash mode and reduce the flash unit's output level. It does so in TTL mode by dropping flash output by 1.5 stops. Between 10 and 13 EV the camera will smoothly lower the flash unit's output...

AF assist light

It's very hard for cameras based on passive autofocus mechanisms this includes all EOS cameras except the manual-focus EF-M to focus when it's dark, since they rely on contrast between light and dark areas. For this reason many EOS cameras have a built-in light that automatically illuminates in low light situations to help the autofocus system to work. On many of these cameras this is a relatively discreet patterned red light from a bright red LED light emitting diode , but on some it's an...

Manual flash triggering for light painting

A fun way of taking interesting photos in the dark is to trigger a flash unit manually whilst leaving the shutter open - sometimes called open flash. For example, you could set your camera on a tripod, open the shutter by putting the camera into bulb mode, and then walk around the scene with a flash unit, painting the scene with light. Coloured gels can be taped over the flash head as well, to illuminate the photo with different colours of light. Canon Speedlites with manual controls or old...

How wireless ETTL works

Canon's wireless E-TTL system employs brief digitally-encoded pulses of light either visible or infrared, depending on the master unit used to transmit commands from a master flash unit to a slave unit or multiple slaves. It doesn't use radio signals like most third party systems, so you can't trigger flashes remotely from great distances, such as the other side of a sports arena. But it's ideal for quick, portable and flexible flash setups in smaller spaces. Canon chose light-controlled...

Enabling second curtain sync

This depends very much on the camera and flash unit that you're using. Early on, Canon put control for this feature on the flash unit. Later they switched to putting control for this feature on the camera body. So whether you have second-curtain sync available to you depends on a complicated set of permutations. Many mid to high end Canon flash units, listed below, have a button or switch which lets you enable second curtain sync. It's usually marked with a triple triangle gt gt gt symbol or...

Flash exposure lock FEL

EOS cameras type A which support E-TTL also support flash exposure lock when used with EX flash units. This feature lets you lock flash settings in, then optionally recompose the image before taking the final photo. This allows you to adjust the flash settings in certain difficult to meter cases. Canon first introduced FEL in 1986 with their T90 camera and 300TL flash, but dropped the feature with the first EOS cameras. It wasn't until 1995, with the introduction of the Elan II E 50 55 and...

Exposure value EV

The sensitivity of camera gear at autofocussing or determining correct exposure metering is rated in terms of EV - exposure value - for a given lens type and film speed. Since the amount of light hitting the surface of film is determined by exposure time shutter speed and lens aperture, exposure values are simply combinations of shutter speeds and apertures. For example, f4 at 1 30 sec has an EV of 9, which is the same EV as f2 at 1 125. Toomas Tamm has a complete EV table on his Web site. Both...

Which bodiesflashes have FEC

Flash exposure compensation may or may not be available to you, depending on which camera body and flash you have. Most midrange EOS cameras support FEC for internal flashes, but most low-end EOS cameras do not. Also, remember that FEC will not work in the basic PIC metering modes - just P, Tv, Av and M modes. For FEC to work with an external flash you need one of the following two cases either both a camera capable of supporting FEC on external flash units and a flash unit capable of receiving...

Disabling ETTL

There are times when TTL metering may be more desirable than E-TTL. A common example is a studio setting where analogue optical slave units can be fooled by the E-TTL preflash. The 550EX, MR-14EX and MT-24EX let you disable E-TTL via a custom function, but they're the only ones. All other EX flash units will always operate in E-TTL mode when mounted to an E-TTL-capable camera, even if the camera is also capable of supporting TTL. One way around this is to buy Canon's Hot Shoe Adapter for wired...

The Off Camera Shoe Cord

The OCSC 2 is a simple coiled cord with sockets on either end that lets you attach a flash unit to your camera's hotshoe and move the flash independently of the camera, up to a distance of about 60 cm 2 feet . This cord, though expensive, preserves all flash functions including E-TTL if it's available, and is useful for mounting a Speedlite flash to a flash bracket. It's pretty short, however. You can connect two of them together if you need more distance, but Canon do not recommend this...

Flash exposure compensation FEC

There are times when you may want to adjust the total flash output from a flash unit above or below what the assumed mid-tones that the camera thinks you probably want. For example, a scene that's mainly white or mainly dark will fool automated sensors, so you may want to override the flash unit. This is flash exposure compensation referred to as fill-in ratio control or flash level control in older Canon material. As noted in the section on fill flash, a common application for flash is...

German Flash Canon

Metz, a respected German maker of flash units, sell quite a few Mecablitz flashes that work with EOS cameras by means of an adapter system. Photozone list some of them - the 54MZ-3, 50MZ-5, 40MZ-3, 40MZ-1, 40MZ-3i, 40MZ-1i, 40MZ-2, 40AF-4 and 32MZ-3 - and describe their features. The Metz range is, in fact, much more extensive than Canon's, and Metz offers features that Canon do not - such as flash units with memory settings, built-in secondary reflectors, clip-on coloured filters and audio...

List of which bodiesflashes have FEC

Camera bodies which do not support any kind of FEC even with flash units with external FEC controls Camera bodies which only support FEC when used with an external Speedlite flash unit which has FEC controls EOS 600 630, RT, 700, 1, 10 10s, all EOS 1000 series cameras, all EOS Rebel series cameras, all EOS Kiss series cameras, 300, 300V, 500, 500N, 5000 888, 3000 88, 3000N, IX Lite IX 50 IX 7. Camera body which supports FEC on the internal flash but not on external flash units unless they have...