Thanks for the replies chaps, I am finding some planes are better than others for screenshots. Usually any done for FSX are pretty good but some of the port overs are not so great. The problem is not the plane, but how the scenery displays. With FSX only machines the scenery is quite well defined and crisp, with some of the port-over ones the scenery gets quite blurred and the frame rate suffers quite badly. These days I mostly use ORBX scenery, may be that has something to do with it.
Cheers
Rich