Walter Mitty wrote:
Is this lens incompatible with the built in flash? I keep getting a
shadowy half moon at the bottom of the picture.

Thanks to all.

It is the wide angle setting picking up the lens obstructing the flash.

As a newbie it never entered my mind to check built in flash
compatability : a lesson now well learnt. I'm also very surprised not to
have seen this mentioned din online Tokina reviews.

Will a Speedlight 800 be ok, since its considerably higher when shoed in?