20D + 28-200mm USM Fringeing

Hi Photographers

Using a 20D. Just got a 28-200mm USM - OK, I know - but I thought it diplomatic not to plash out on an L type just at the moment - later perhaps.

Anyway, to cut a long story short I have taken a few test shots at max 200m, the obvious quick subject this time of year was the daffodils in the garden. I used RAW+JPG.

When I went to a rather large blow-up I noticed some blue fringeing around the white petals, and some green fringeing around the yellow.

I have used a tripod for my shots. I seems a tripod is somewhat necessary? The JPGs also have similar characteristics - Do you think it is a lens problem - or am I expecting too much for a lens with such a range?

Thanks for any comments.

Its called Chromatic Abberation and a sad fact of digital imaging. Can you post a pic to make sure?