[Help] unable to use nikon AF-assist illuminator w tokina lens


Senior Member
Apr 24, 2005
Can someone enlighten me on why the nikon AF-assist illuminator on my sb900 does not turn on the red light when tokina lens is been attached on? the setting is the same as the nikon lens i use.


Center Weight Metering
AF area selector - Single Point AF
Single Shot Selector

what went wrong?

Thank You!

tried using the centre af point?

you mean default focus box in the middle? yes, done so.

Is AF speed affected?
Maybe the camera decides that it's bright enough to achieve focus lock, so the red light doesn't come on.
The AF assist lamp on my SB600 doesn't come on with every shot that I take, except generally in low light (eg. indoors).

you mean default focus box in the middle? yes, done so.

If you've done everything, it just means that the lens is not fully compatible. These are some inconveniences you need to learn to accept when using 3rd party lenses.

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why not share with us wht lens is it that you are using, and maybe we can offer more help.

i know my tokina lenses all work. so what tokina lense you using?

o sorry for not placing the tokina lens type. it is 11-16mm f2.8

i had already set AF-assist illuminator on my d300 body to 'ON' whereby under all condition it should be turn on, as tested by my 50mm.

Did u accidentally set the focus drive mode to AF-C when you attached the Tokina lens? I know you said all settings were the same, but just want to make sure. AF-C does not support AF-assist. Only AF-S and AF-A will support AF assist.

you mean the switch beside the lens? yea, it is in S all the time :)