Wireless Flash on Canon EOS Digital Cameras In this tutorial, the term "Master" refers to a controller for off camera flashes that sends commands. The term "Slave" refers to any off camera flashes that receive those commands. Nikon use the more politically correct "commander" and "remote", but Canon still uses the old terms, so I'll use them here in order to avoid any confusion. To use this tutorial, you'll need a 580EX I or mk II flash mounted on your camera. You could also use an ST-E2 wireless transmitter, but I don't cover the use of that in this tutorial, as I've never used one. It wouldn't be too hard to adapt this tutorial for it though, as the principles are the same as what is described here. In any case, you will need some kind of master unit attached to your camera. While Nikon cameras are able (in some camera models) to use the pop-up flash as a commander unit, none of the Canon cameras are able to, which seems to be a rather poor design idea. However, using a 580EX I or mk II as a master unit does have five advantages over the ST-E2: 1. You can aim it in any direction you want, giving you more flexibility in your slave flash placement 2. It will allow you to control Group C slaves. 3. It will give you greater range that the ST-E2. 4. It will also let you add an illuminating flash from the master unit (the ST-E2 can't produce any visible light of its own). 5. Finally, the ST-E2 works only in E-TTL II mode. You can't use a manual set up. For my tastes, the disadvantages of the ST-E2 are too great, so I use a 580EX II as my on-camera master. I will assume that you have a 580EX II flash mounted on camera as a master, and are using 430EX II or 580EX II flashes as off camera slaves. However, if you are using the original versions of these flashes, they will also be covered. There are some small changes, as the controls are slightly different, and the 580EX I cannot be controlled through the camera menus. On newer EOS cameras, the master flash mounted on camera is able to be controlled directly from the camera body. It is recommended that the Flash Control menu option be added to the My Menu on the camera, to make it easier to find. Once you have the flash control in the My Menu section, you can get to the controls for the wireless flash settings by going to My Menu]Flash Control]External Flash Function Setting] Wireless Settings. All steps that involve changing menu settings will proceed from the External Flash Function Settings menu. There are two situations you may find yourself in that leave you unable to control the master flash through your camera's menus. You may find that you have the 580EX I which can't be used via the camera's menu, or you may find that your camera doesn't have the menu option available to control the master flash. In both of these cases, instructions on how to make the required adjustments from the flash itself will be provided as well. If you are using the 580EX I or the 430EX I, the master/slave setting is controlled by a two or three way switch underneath the rear dial or +/- buttons of the flash. On the 580EX I, the three positions are "Off", "Master", and "Slave". The switch on the 430EX I only gives the options of "Off" and "Slave" as it can't function as a master flash. The reason for the change is that the newer flashes can be controlled through the camera menus, and the master/slave switch can't be used if it is a physical switch. With the exception of setting the flash as a master or slave, the instructions given here for the 580EX I and 430EX I will also work for the 580EX II and 430EX II. Setting the Master and Slaves In order to operate as wireless flashes, the 580EX II flash on the camera must be set as a master to send the wireless signals and each 430EX II flash must be set as a slave to receive those signals. 1. If you have a 580EX II mounted on camera, choose the Wireless Function setting in the Wireless Settings menu and set it to Enable. The on camera 580EX II is now set to be a master flash. Alternatively, press and hold the ZOOM button for a few seconds. It will go into wireless mode. Then rotate the rear dial of the flash to select the Master icon. Go to Step 3. 2. If you are using the 580EX I, flick the switch under the main dial to MASTER.) The 430EX II flash cannot function as a master. 3. If you are using a 430EX II or 580EX II as the slave unit, press and hold the ZOOM button. After a few seconds, the flash will go into slave mode. (If you are using a 580EX II, pressing and holding the ZOOM button puts the camera into wireless mode. Use the rear dial of the flash to switch between master mode and slave mode.) 4. If you are using a 580EX I or 430EX I flash, flick the switch under the main dial to SLAVE. The wireless signals are sent as encoded pulses of light (infra-red light if you are using the ST-E2 transmitter). They are too fast for the eye to register. When you are placing your slaves, bear in mind that if they cannot see the pulses of light coming from the master, they will not fire. Outside in direct sun, it will be difficult to place the slaves where they will detect the command signals. Indoors is a much more forgiving environment, as not only is there no bright sunlight to interfere with the signals (the signals will have a greater range), but you can also bounce the signals off walls, which allows you to place the slaves out of direct line of sight of the master. However, always check to make sure your slaves are receiving the command signals from the master. Setting the Communication Channel There are four channels available to use with Canon's wireless flash. This allows several set ups to be used in close proximity without interfering with each other. This can allow several photographers to have their own lighting set ups, or it can allow one photographer to have several lighting set ups and choose which set up to use. 1. If you are using a 580EX II as the master, select the Wireless Settings menu, then go to Channel. There are four different channels that can be set. Choose a channel by pressing the SET button, and then using the rear dial to cycle through the different channels. Press the SET button again to lock in the chosen channel. Go to step 3. 2. If you are using a 580EX I as the master, press the ZOOM button until the CH. icon blinks. Rotate the rear dial to choose the same channel that you want to use. 3. On the slave, press the ZOOM button until the CH. icon blinks. Press the +/- buttons to choose the same channel that you set for the master flash. NOTE: The master flash will fire ALL slaves that are set to the same channel as it. If you are in a location with other photographers using Canon's wireless flash, make sure you are not using the same channel that they are, otherwise you'll find that their slaves fire at the same time as yours (ruining your lighting set up), and your flashes will fire when theirs do (draining your batteries faster). Setting Slave Flashes to Different Groups Having slaves set to different groups is not required for all wireless flash functions, but can offer greater flexibility. Unless you need slaves to be in different groups, keep all the slave flashes in Group A. 1. On the slave flash, press the ZOOM button until the Slave icon blinks. 2. Use the +/- buttons or the rear dial of the flash (depending on whether you are using a 430EX or 580EX model) to change the group to either A, B or C. 3. Press the ZOOM button again to lock in the changes. This procedure will work no matter which model flash you are using. Enabling or Disabling the Master Flash As well as triggering remote slave flashes, the master flash can also provide illumination. If you are using the 580EX II, use this procedure: 1. Choose the Wireless Settings menu, then choose the Master Flash option. 2. Cycle through the Enable/Disable options. When Enable is chosen, the master flash will fire an illuminating flash as well as the control flashes for the slaves. If Disable is chosen, only the control flashes will fire. If you are adjusting the settings via the flash instead of the menus, follow this procedure: 1. Press the ZOOM button several times until the icon representing the beams of light from the flash on the rear panel flashes. 2. Rotate the control dial to switch between the On or Off settings. 3. Press the ZOOM button again to confirm the setting. NOTE: Even when the master flash is disabled as above, it will still fire when the photo is being taken. This is a very low power control flash that tells the slaves when to fire. It does not provide enough light to alter the flash exposure. However, this flash is still enough to be reflected, and may be seen in any reflective surfaces. NOTE: If the master flash is set to fire an illuminating flash, it will fire as Group A. Using Wireless E-TTL II Flash Off camera flash can operate the same way as fully automatic on camera flash. This is actually easier to set using the flash controls rather than the camera menu, so I'll describe this method first. 1. Press the MODE button on the rear of the flash to cycle through the available modes until the ETTL icon is displayed on the LCD screen. 2. The slave flashes will now function in E-TTL mode. 3. If you require any flash exposure compensation, it can be set by rotating the rear dial of the flash. To set the flashes to E-TTL II mode using the camera menus: 1. On the External Flash Function Setting menu, choose Flash Mode. 2. Press SET and then use the rear dial to select E-TTL II. 3. The slave flashes will now function in E-TTL mode. 4. Any required flash exposure compensation can be set using the camera’s menu as well. However, the flash must be set to zero flash exposure compensation, otherwise the menu option will be greyed out. It is easier to set flash exposure compensation from the dial on the rear of the flash. Press SEL/SET button on the flash and then rotate the dial. Adjusting Ratios with Wireless E-TTL II Flash This procedure allows automatic flash, but also allows the slaves in different groups to fire at different levels in order to create a variety of lighting effects. At least two slave units set to different groups as described above are required for this (if you have set the master unit on the camera to fire an illuminating flash, then you can use it as one group and a single off camera slave as another group). If you have two slave groups, set one group to Group A and the other to Group B. If you have three groups, set the third group to Group C. If you have the 580EX II as your master: 1. Ensure that you have at least two slaves set to different groups (see above). 2. Ensure that the flash mode is set to E-TTL II (see above). 3. Open the Wireless Settings section of the menu. 4. Scroll down to Firing Group. 5. If you have two slave groups, choose A:B. If you have three slave groups, choose A:B C. (Note that this is NOT the first option A+B+C, which will make all slaves fire as Group A!) 6. Now select the A:B Fire Ratio setting. Press the SET button and rotate the rear dial to alter the ratio between groups A and B. The ratio describes the relative strength of Group A to Group B. See below for an explanation of ratios. 7. If you have a Group C, then the flash output of Group C can be controlled through the menu setting Group C Exposure Compensation. If you are adjusting the ratios by using a 580EX I, follow this procedure. This method will also work with the 580EX II. However, if you are using the 580EX II for this, note that there are a few differences between the 580EX I and the 580EX II, but these differences are limited to how many times you need to press the SET button to get to the different settings. This is easily overcome by looking at the LCD screen. 1. Press the ZOOM button until the RATIO icon blinks. 2. Rotate the main dial. There are three settings: Off, A:B and A:B:C. Use the A:B setting if you have two groups, and the A:B:C setting if you have three groups. Press the SET button in the middle of the main dial. 3. Press the SET button again to move through the options. After pressing it three times, the display will flash A:B. The C will not flash at this point. 4. Rotate the main dial to adjust the ration between Groups A and B. 5. Press the SET button again. Now the C icon will flash. 6. Rotate the main dial on the flash to set the light output level for Group C. This isn't displayed on the ratio slider at the bottom of the flash's LCD screen, but as flash exposure compensation. Think of it as "Group C exposure compensation". NOTE: If the master flash is firing an illumination flash as well as the control flashes, it will fire as part of Group A. NOTE: The way Canon has designed the system means that you're best to use Group C as a hair light or a background light. If you use it to illuminate the subject, then you run the risk of over-exposing the subject. UNDERSTANDING RATIOS: A ratio of 1:1 means both groups fire at the same strength. A ratio of 2:1 means that Group A fires two units of light for every one unit that Group B fires (Group A is one stop brighter than Group B). A ratio of 4:1 means that Group A fires four units of light for every one unit that Group B fires (Group A is two stops brighter than Group B). A ratio of 1:8 means that for every one unit of light that Group A fires, Group B fires 8 units of light (Group B is three stops brighter than Group A). However, this assumes that each group has the same number of slave flashes. If Group A has one flash and Group B has two flashes, then a ratio of 2:1 will result in balanced light. Even though Group B is firing at half the power of Group A, Group B has double the number of flashes and thus produces double the light. NOTE: To set an overall flash exposure compensation, press the SET button in the middle of the main dial until the flash exposure compensation value is blinking while the Groups icon shows A:B C. Using Wireless Manual Flash With wireless flash, the flash output of up to three groups of slave flashes can be controlled manually. This is good for studio lighting, as it allows you to set a key light, background light and a hair or rim light, each with a different output. If you are using a 580EX II: 1. In the External Flash Function Setting menu, make sure the Flash Mode is set to Manual Flash. 2. Scroll down and select the Wireless Settings menu option. 3. Scroll down to Firing Group. If you want to use only one group (such as if you are only using a single slave flash), choose A+B+C. If you are using two slave groups, choose A:B. If you are using three slave groups, choose A:B C. (Using A+B+C when using only one flash group will force all slave groups to act in a single flash group. Groups A, B and C will all fire at the same strength.) 4. If A+B+C is set, then you can only set the strength of Group A. (All slaves will fire at the output level set for Group A, even if they have been set to Group B or C.) 5. If you have slaves in two groups and have set the firing group to A:B, then you can set the output of Groups A and B. 6. If you have three groups of slaves and have set the firing group to A:B C, then you can adjust the output of Groups A, B and C. If you are using the 580EX I, follow this procedure: 1. Press the MODE button on the master unit until the LCD screen shows the M icon. 2. Press the ZOOM button until the Ratio icon blinks. 3. Rotate the main dial until A:B or A:B C blinks (depending on whether you want two groups or three groups). 4. If you are using these steps to set a 580EX II, then setting the ratio to Off is the same as setting the groups to A+B+C via the menu. NOTE: If you have the Master Flash set to fire an illuminating flash as well as the control flash, it will fire as part of Group A. As any illuminating light from the master flash will look pretty bad unless it is being used simply as fill light, I recommend that you set Group B or Group C to be your main light and leave Group A to be just a fill light. It would be great if Canon allowed you to adjust the Master's output independently of any of the groups, but they decided not to. Using Slave Flashes as Optical Slaves If you want to, you can set your slave flashes so they function as optical slaves only. This means that the master flash tells them when to fire, and communicates no other information. This has the advantage that you can set as many differently set flashes as you want (instead of being confined to the three groups you'd normally be stuck with), but it does mean that you can't control the slaves from the master. Any alterations of settings must be done by actually walking over to the slave and changing the settings there - not always feasible if they are mounted in a hard to reach location. 1. On the Slave flash, press and hold the MODE button until the ETTL icon vanishes and is replaced by a flashing M icon. The slave flash is now in manual mode. 2. Press and hold the SET button until the power reading flashes. 3. Adjust the power of the flash by pressing the +/- buttons or rotating the dial. 4. Press the SET button again to lock in your settings. 5. Repeat this for each flash. Note that if you have your slaves in manual mode, the A, B or C icons that identify which group the slave is in aren't used, because they are essentially ungrouped. The master is only sending a signal that says "Fire now!" without specifying what power level to fire at. The power level is being set at the slave flash. Final Notes There are four main units available for use as a master in Canon's wireless flash system; the 580EX I, the 580EX II, the ST-E2 transmitter and the 550EX flash. This tutorial only covers the use of the first two, as they are the only units with which I have had experience. If you have one of the other units that you are using as a master, please check your manual to see exactly how to set it up. While the principles are undoubtedly the same as what I have described here, the steps taken to achieve them may be slightly different. If you are looking to set up a wireless system using the one used by Canon, then I recommend getting a 580EX II flash for a master and a 430EX II flash as a slave. One flash may seem limiting, but the greatest benefit of off camera flash is that it is off camera, not the number of individual slaves you can use. A single off camera flash used well can give you fantastic light.