Af assist on canon flash 580exii not working

You need to set the flash to slave and the same channel as the master. If the flash doesn't have this function it may be able to be fired optically. Set the master flash to low power and set the off camera flash to optical.

It sounds like your camera settings have the( AF Assist Beam) on Off? That is the Amber Color light you see when you half press the shutter button. If that setting is set to OFF, then the camera can not focus in low light giving you blurry pictures as it can not see any light to assist the camera on focusing. If you turn on the (AF Assist Beam) to on, they when you press the shutter button half ways down you will see a Reddish/ Amber light, that light helps the camera find a focus point, giving you a slightly better low light photo.

You didn't say what camera model you are using.
If you have 7D/60D/T4i you can have a total of 3 wireless ir flashes.

580EX II must be set at Master, say Group A & Channel 1
Two 270EX II must be set at Slave, say Group A & Channel 1
or
One 270EX II set at Group A & Channel 1
Second 270EX II set Group A & Channel 2


Then go into camera menu & turn off Master flash & turn settings for those two flashes.



Send me a email, then I can help you much better.

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• See page 87 of the manual to see which settings the AF-Assist does NOT work

• also custom function C.Fn.III - 5 0n page 179 has an option to disable the AF assist
• direct link to manual http://gdlp01.c-wss.com/gds/1/0300001591/01/eos50d-h-en.pdf

Focusing in low light can be difficult for the autofocus system and sometimes you will need to use the manual focus, you can select the magnified image and see if that helps
See the online manual - page98 refers to how to magnify the image - using the magnify button - changes between 5X 10X and full screen
To help the camera autofocus there is an assist beam - this takes the form of flashes from flash to help the AF system focus - make sure it is ON - there is a custom function full details on Page 157 C.Fn III: Auto focus/Drive 6 AF-assist beam firing
FYIThe support site for this camera is here, including online manual http://software.canon-europe.com/products/0010629.asp

• If this solutions solves you problem, please do not forget to rate my solution.
• If not, then please comment back so I can help some more

Turn off the Pre-flash from the camera /or 580EX 2.

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In low light situations, connect a speedlite flash to your body (e.g. 430EXII or 580EXII). These flashes emit a AF assist beam to assist focussing in low light situations.

No.

One is IR(infrared) sensor. If this one comes on, you can not see it. It's invisible to the naked eyes. Only animals, snakes and IR cameras can see it.
The red light that you see when pressing lightly on the shutter button is the AF assist light, not a sensor.

You can see that by looking at a mirror.

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I do medical/photo equipment repairs & IR conversion, but I'm in the USA.
Over 20 years and Canon knew about that problem including many photographers. Most of Canon flashes can not do manual or aperture mode because they have to flash sensor.
Now they have it on the 580EXII. I guess Canon has no photographer working in the flash department.

Canon screwed photographers, buy a Metz, Vivitar, Sigma, Sunpak, or NIkon.

Alexander
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Check out LEE Filter or Kodak IR Filter
Place that filter over AF Sensor.

Or try ti find remote(TV/VCR/DVD/radio) control unit with a large filter over led.

You can still glue those broken part and glued it back as close as possible.

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