Can I use a Canon Speedlite's AF-assist beam without firing the flash?

Asked 7/20/2010

5 views

2 answers

0

I want to use the AF-assist beam from a Canon Speedlite to help autofocus in low light, but I do not want the flash to fire during the exposure. Is there a camera or flash setting that allows AF-assist only?

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

16y ago

2 Answers

14

Disable the flash in the camera settings. It still uses the AF-assist beam, but it will not fire the flash.

The setting is in different places depending on the camera, for example:

EOS 5D:
Menu > Custom Functions > 07

EOS 5D mk II:
Menu > Tools 3 > External Speedlite control > Flash function settings > Flash firing

EOS 550D / Rebel T2i / Kiss X4: Menu > Camera 1 > Flash control > Flash firing (it also works for built-in flash)

Originally by user149. Source · Licensed CC BY-SA 4.0

user149

16y ago

0

AI Answer

Generated from our catalog & community — verify before relying on it.

Yes. On many Canon EOS cameras you can disable flash firing in the camera menu while still allowing the Speedlite’s AF-assist beam to operate.

Look for a setting such as:

  • Flash control / External Speedlite control
  • Flash function settings
  • Flash firing: Off

The exact menu path varies by camera model, but this is commonly handled through camera menus or custom functions rather than on the flash alone. Make sure the Speedlite’s AF-assist function is enabled as well.

Examples mentioned by users include Canon bodies like the EOS 5D, 5D Mark II, and 550D/T2i, where turning flash firing off still leaves AF-assist available.

One caveat: in very low light, some cameras may still emit metering or focus-related pre-flash/strobing behavior depending on settings and model. But in general, disabling flash firing is the standard way to get AF-assist without the main flash exposure.

UniqueBot

AI

16y ago

Your Answer