Chapter 6: Understanding Canon's Fill Flash System Secrets in Depth

/ L. David Likes Photography/

I define Fill Flash as any time you set the Flash Exposure Compensation (FEL) to a negative value. Canon automatically sets an approximate 50% Fill Flash anytime you are in a program mode and are using E-TTL flash. Yet I find this amount of flash too harsh for portraits.

To set up hand held. Adjust the ISO manually until you have a high enough shutter speed for the given lens.

I’ve put some guide settings that work well for me (shown below). Try them and see if they work for you? You may have to tweak them but you should be in the ballpark when needing to get a good exposure.

Setting Fill Flash correctly when using program mode and evaluative metering

Depends on number of stops of fill you want:

Set one stop negative fill (at the flash -1). Set ambient exposure to +⅓ stop (one click)

Set two stop negative fill (at the flash -2). Set ambient exposure to +⅔ stop (two clicks)

Set three stop negative fill (at the flash -3). Set ambient exposure to +⅔ stop (two clicks)

Adjust the focus point on the eye and take the shot.

(Note: Camera sees the flash and Ambient as one exposure so it reduces ambient approximately one stop in its internal calculation. So you need to make up for that otherwise the image will be underexposed)

Camera now sees flash and ambient light as two separate exposures so now need to do just the opposite of what was mentioned in the previous fill flash definition (otherwise you will get a 1 stop overexposure). To set up hand held. Adjust the ISO, shutter and aperture manually until you have a high enough shutter speed for a given lens.

Setting Fill Flash correctly when using manual camera mode

Depends on number of stops of fill you want:

Set one stop negative fill (at the flash -1). Set ambient exposure to -⅔ stop (two clicks)

Set two stop negative fill (at the flash -2). Set ambient exposure to -⅓ stop (one click)

Set three stop negative fill (at the flash -3). Set ambient exposure to -⅓ stop (one click)

Do an FEL on the bright side of the face. Then focus on the eye. Recompose and shoot.

You are adjusting ambient exposure manually by adjusting the needle when looking through the viewfinder.

Note: Manually set you ambient exposure needle to a -1 stop if you choose not to use fill flash when in manual camera mode. This will give you correct exposure when using E-TTL flash.