Thanks Tony, a recent firmware update to the camera has given me some in camera focus stacking which means I can use the lens where it is most sharp and get a good depth of field. The downside is nothing can move during the exposures, so camera on a tripod but even the most gentle of breezes during the exposures gives to much movement for it to work. Even when I think everything is perfectly still I only get a 1 in 3 or 4 success rate.