flash exposure compensation

On the tenth day of Christmas…

Ten Lords a Leaping – well they certainly are if they get their flash exposure compensation in a mess. So today i’m peering in to the world of Canon flash exposure compensation.

With Canon cameras there are independent controls for exposure compensation and flash exposure compensation. In addition there are two possible places to set flash exposure compensation; on the flash or on the camera body.

What is flash exposure compensation?

Flash exposure compensation is used to increase or decrease the flash output relative to the automatically determined power output.

If the flash is already giving out full power, it is not possible to get more out of a flash by setting flash exposure compensation to +3

Setting flash exposure compensation on the camera body

You can set the flash exposure compensation on the camera body since it is not possible to set flash exposure compensation on all the Canon Speedlites. Speedlite 270EX II this means you!

If you only have one flash and it’s on the hotshoe then using the camera body is a good option.

EOS 7D Mark II flash exposure compensation

Button to set EOS 7D Mark II flash exposure compensation


With practice and some control familiarity I can move my fingers to the flash exposure compensation button and turn the camera rear control dial, while watching the change in setting in the optical viewfinder.

flash exposure compensation on camera

Flash exposure compensation set on the quick control screen to +2

Not all cameras have this set of distinct buttons and controls so the camera menu or info display needs to be accessed.

1501BWP42298Sometimes you find that the camera is unable to set the flash exposure compensation, this is due to the flash already having flash exposure compensation set. The flash setting has priority over the camera. 

 Setting flash exposure compensation on the flash

setting flash exposure compensation on the flash

Setting flash exposure compensation on the Speedlite 600EX-RT

Most of the Canon Speedlites allow flash exposure compensation to be set on the flash. If flash exposure compensation is already set on the camera body then changing the setting on the flash takes priority over the camera setting. However as soon as the setting on the flash is set to zero, the camera body setting becomes active again…

flash exposure compensation on flash

Flash exposure compensation was set on the flash to +1, blocking changes from the camera

Once the setting is chosen on the flash, then the camera control is blocked.

Speedlite 600EX-RT C.Fn 13

Speedlite 600EX-RT C.Fn 13

I usually make use of Custom Function C.Fn 13 in my Speedlite 600EX-RT to allow flash exposure compensation to be controlled just by turning the rear dial on the flash. This is also possible to set on other Speedlite flash so check your manual.

Flash exposure compensation for off-camera slave flashes

Slave flash set with -1 flash exposure compensation

Slave flash set with -1 flash exposure compensation

If you start to use multiple off-camera flash, it is possible for each slave to have it’s exposure compensation set. This can be both a real help, or a real pain.

If you set two flashes up, and they are in a fixed place on stands, your subject is in the same place for a few shots.

You decide that you would like one of the two flashes to be a fill light, and say 2-stops less powerful than the other flash.

Set -2 on the fill flash and leave the other flash at zero and put both flashes in the same group.

Now they will always be two stops apart regardless of using E-TTL or Manual mode.


See you tomorrow for another in the 12 tips for Christmas…

All I want for Christmas is you…

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This is one of a series of twelve posts, inspired by the popular Christmas song The Twelve Days of Christmas. I’m giving all my blog readers a free tip for each of the twelve days.

About the twelve days of Christmas

The Twelve Days of Christmas start with Christmas Day and ends with the eve of Epiphany on January 5 th. The Twelve Days of Christmas dates back to English origins in the sixteenth century although the music is reputed to be French. The first publication date for The Twelve Days of Christmas (The 12 Days of Christmas) was 1780.

source: 12 days of Christmas

About the author

Full-time photo tutor and photographer. I love to share my knowledge and skills to make photos, videos and teach others. I write books and articles for photo magazines and I always have at least one Speedlite flash in my camera bag