430 iii speedlite infra red beam didn't fire in low light situations

[secondlevel]

I was shooting a birthday event and the infrared beam didn't fire. I had to use my cell phone to create enough light to focus! I found the settings to change online but I am confused. I had another event and the infrared fired. I didn't change anything since my last job!

The article that I read stated that the new 430 model by default is set to prevent the infrared from firing and it will only activate when using the center focus point. I know I need to read the manual. I didn't think it would be that big of a difference upgrading from the 430 ii.

What is going on?

[jrhoffman75]

http://photo.stackexchange.com/questions/71916/why-isnt-infrared-af-assist-beam-the-default-when-ava...

[TTMartin · Accepted solution]

The IR focus assist will only work in One Shot AF mode. If you are using AIServo it wont.

[secondlevel]

I want to say thanks for the reply. I can't recall if I changed it to continous focus; however, it explains why it might not have fired.