C.Fn-01 SET function when shooting

You can change the function assigned to <>. With C.Fn-01-1/2, you can press , then look at the LCD panel and set <> directly.

0: Default (no function)
1: Change quality

Enables you to select the recording quality directly.

2: Change parameters

Enables you to select the processing parameter directly. "PA-P1, P2" stand for Parameter 1 and 2, and "PA-1" to "PA-3" stand for Set 1 to 3. "PA-B/W" is for monochrome.

3: Menu display

Gives the same function as the <MENU> button.

4: Image replay

Gives the same function as the <> button.

C.Fn-02 Long exposure noise reduction

0: Off
1: On

Reduces noise in exposures 1 sec. or longer. After the picture is taken, the time required for noise-reduction processing will be the same as the exposure time. During the noise reduction processing, "" will be displayed and shooting will not be possible.

C.Fn-03 Flash sync speed in Av mode

0: Auto
1: 1/250sec. (fixed)

Sets the flash sync speed to 1/250 sec. in the aperture-priority AE (Av) mode. (Against dark backgrounds such as the night sky, the subject's background will look dark.)

C.Fn-04 Shutter button/AE lock button

0: AF/AE lock
1: AE lock/AF

Convenient when you want to focus and meter separately. Press the <*> button to autofocus and press the shutter button halfway to attain AE lock.

2: AF/AF lock, no AE lock

In the AI Servo AF mode, you can press the <*> button to stop the AF operation momentarily. This prevents the AF from being thrown off by any obstacle passing between the camera and subject. The exposure is set at the moment the picture is taken.

3: AE/AF, no AE lock

This is useful for subjects which keep moving and stopping repeatedly. In the AI Servo AF mode, you can press the <*> button to start or stop the AI Servo AF operation. The exposure is set at the moment the picture is taken. Thus, the focusing and exposure will always be at the optimum point as you wait for the decisive moment.

C.Fn-04 and C.Fn-17-0, 1, 2 have AF start/stop and AE lock functions. If you have set these Custom Functions and you execute Custom Function operations, the latter operation will not work. The only exception will be when AF stop is executed after AF start.

C.Fn-05 AF-assist beam

You can set the AF-assist beam to be emitted from the camera or EOS-dedicated Speedlite.

0: Emits
1: Does not emit

AF-assist beam not emitted.

2: Only ext. flash emits

When an EOS-dedicated Speedlite is used, the AF-assist beam is emitted only when necessary. When the built-in flash is used, the AF-assist beam is not emitted.

C.Fn-06 Exposure level increments

0: 1/3-stop
1: 1/2-stop

Sets 1/2-stop increments for the shutter speed, aperture, exposure compensation, AEB, etc.

C.Fn-07 Flash firing

You can enable the built-in flash, external Speedlite, and non-Canon flash connected to the PC terminal to fire.

0: Fires
1: Does not fire

The flash will not fire.

C.Fn-08 ISO expansion

0: Off
1: On

For the ISO speed, "H" (equivalent to ISO 3200) will be selectable.

C.Fn-09 Bracket sequence / Auto cancel

You can change the AEB sequence when the pictures are bracketed with the shutter speed or aperture and the file-saving sequence for white balance bracketing (WB-BKT).When "Auto cancellation" is set, bracketing will be canceled in the following cases:

AEB: You turn the <> switch to <OFF>, change lenses, have flash ready, replace the battery, or replace the CF card.
WB-BKT: You turn the <> switch to <OFF>, replace the battery, or replace the CF card.

0: 0, -, +/Enable
1: 0, -, +/Disable

The first bracketed shot is the standard exposure (or exposed with the standard white balance). This bracketing sequence can be repeated. 

2: -, 0, +/Enable

Starts the bracketing sequence with the minus (bluish or magenta bias) setting.

3: -, 0, +/Disable

Repeats the bracketing sequence starting with the minus (or bluish or magenta bias) setting. This bracketing sequence can be repeated.

AEB	WB bracketing
	B/A Bias	M/G Bias
0: Standard exposure	0: Standard white balance	0: Standard white balance
-: Decreased exposure	-: More blue	-: More magenta
+: Increased exposure	+: More amber	+: More Green

C.Fn-10 Superimposed display

0: On
1: Off

The AF point in the viewfinder will not flash in red. Recommended when it is ersome to see it light up.

The AF point will still light when you select it.

C.Fn-11 Menu button display position

When you press the <MENU> button, you can set the menu screen setting.

0: Previous (top if power off)

Displays the preceding menu screen that was used. Note that the top menu screen [Quality] will be displayed instead in the following cases: The <> switch is <OFF>, the battery is replaced, or the CF card is replaced.

1: Previous

Displays the preceding menu screen that was used.

2: Top

Always displays the top menu screen [Quality].

C.Fn-12 Mirror lockup

0: Disable
1: Enable

Effective for close-up and telephoto shots to prevent camera shake caused by the mirror's reflex action.

C.Fn-13 AF point selection method

0: Normal

Press the <> button and use <> to select the AF point.

1: Multi-controller direct

Without pressing the <> button first, you can just use the <> to select the desired AF point. Pressing the <> button will set it to automatic AF point selection.

2: Quick Control Dial direct

At first, you can just use the <> dial to select an AF point directly without pressing the <> button. By holding down the <> button and turning the <> dial, you can set the exposure compensation.

C.Fn-14 E-TTL II

0: Evaluative

Fully automatic flash photography for all conditions, from low light to daylight fill-flash.

1: Average

The flash is averaged for the entire area covered by the flash. Since automatic flash exposure compensation will not be executed, you may have to set it yourself depending on the scene. This also applies if you use FE lock.

C.Fn-15 Shutter curtain sync

0: 1st-curtain sync
1: 2nd-curtain sync

When a slow shutter speed is set, you can capture a light trail following the subject. The flash fires right before the shutter closes. This Custom Function can be used to obtain 2nd-curtain sync effects even with EX-series Speedlites which do not have this feature. If the EX-series Speedlite has this feature, it will override this Custom Function.

When 2nd-curtain sync is used, a preflash will be fired for flash metering control right after you press the shutter button completely. Remember that the main flash will fire right before the shutter closes.

C.Fn-16 Safety shift in AV or TV

0: Disable
1: Enable

This works in the shutter-priority AE (Tv) and aperture-priority AE (Av) modes. If the subject's brightness changes suddenly and the current shutter speed or aperture becomes unsuitable, the shutter speed or aperture is shifted automatically to obtain a suitable exposure.

C.Fn-17 Lens AF stop button function

0: AF stop
1: AF start

AF operates only while the AF stop button is pressed. While the button is pressed, AF operation with the camera is disabled.

2: AE lock while metering

When the button is pressed while metering is still active, AE lock is applied. Convenient when you want to focus and meter separately.

3: AF point: M -> Auto / Auto -> ctr.

In the manual AF point selection mode, holding down the button switches to automatic AF point selection. Holding down the button switches from manual AF point selection to automatic AF point selection instantly. Convenient when you are no longer able to focus track a moving subject with a manually-selected AF point in the AI Servo AF mode. In the automatic AF point selection mode, holding down the button selects the center AF point instantly.

4: ONE SHOT <-> AI SERVO

In the One-Shot AF mode, the button switches to the AI Servo AF mode only while you hold it down. In the AI Servo AF mode, the button switches to the One-Shot AF mode only while you hold it down. Convenient when you need to keep switching between One-Shot AF and AI Servo AF for a subject which keeps moving and stopping.

5: IS start

With the lens' IS switch already ON, the Image Stabilizer operates only while you press the button.

The AF stop button is provided only on super telephoto lenses.

C.Fn-18 Add original decision data

0: Off
1: On

Data for verifying whether the image is original or not is appended to the image. When an image appended with the verification data is played back, the <> icon will be displayed. To verify whether the image is original, the Data Verification Kit DVK-E2 (optional) is required.