I am new with Poser so I guess it is not surprising that I have this problem.

here is the detail.

I finished positioning and posing all chars and the only thing left was the background.

I imported the background image into Poser  and everything seemed fine until I rendered it.

As soon as I chose to render, Poser popped up a question telling me that the ratio of the background and that of my screen do not match and asking me whether to change to fit.

I chose to change but then the final image after the rendering has a big problem, that is, the dimension of the background image had been changed.

actually, the background image Shrinked, distorting the elements of the image and losing its original impression.

I attached an image to show the problem. the moon from the background image lost its original shape after rendering, because the dimension of the background image being changed by Poser before rendering. the original shape of the moon is totally round, but after rendering, it changed dramatically.

what can I do?

please help. I use Poser 6. I have No software for postwork.

thank you very much.