FA 24-90 & flash coverage

[P Kong]

For those Pentaxians who use the FA 24-90 w/ the built-in flash on the 
Zx-5n, do you experience vignetting? I don't have a 24-90 (yet) to try for 
myself. And yes, I do have the ability to use an accessory flash, but 
thought I'd toss out the question.

Thanks.

Pat in SF