Well, if you want to use the background image approach, a quick and simple method is to make a reduced resolution copy of the larger image. So make a 500X500 pixel copy, and work with a 500X500 render size to get everything set up, and for the final render resize up to the 1000X1000 and load in the larger image. It means your working size has to be an exact ratio to the final desired size, which has to be the same as your background picture. If you use the background plane approach and attach the background image to that, then it doesn't really matter what resolution you want to use. You just have to make sure that the background plane has the same dimensions as the source background image. So for example, if you have a 653X798 pixel background image, then you load a background plane and set the xScale and yScale respectively to 653% and 798%, and the image will be displayed correctly. Then you can use the full object scale (the plane Scale dial,) to resize the pic/plane to fill the full back ground area depending on how far back you need to move it. For the background plane I usually just use either the square or one-sided-square that comes with Poser. If you have some type of morhing 'sheet' prop though, (or like to play with magnets,) you can get some interesting effects by warping the backgroud plane and thereby warping the backgroung image. Using this plane for the background, you also have the extra ability to move it around and 'crop' the background image to just the/a part you want. In fact, this is a LOT easier than trying to get it to exactly fill the background area of the image And just to run full circle on the whole issue, I usually use the background plane approach to get the background exactly where and how I want, then turn off everything else, (ie make then all invisible,) render just the background plane, then reload IT as the background image That way you wont get shadows falling on it. It does allow you to easily position and crop the background image to exactly where you want.