The integration tool limits integrations to a minimum of 3 images. I'm using this function in a modified Batch Preprocessing tool to combine images from two telescopes in multiple pairs to search for asteroids using the Tycho asteroid search software. But I'm limited to combine not less than 4 total (i.e. two from each scope) due to the restrictions of the image integration function. By combining images from both scopes I'm finding fainter asteroids. If I could combine them just two at a time (i.e. one pair of images) I could also increase the speed of the asteroids I could find using images from both scopes. As it is, to search for faster asteroids, I'm limited to using images from only one scope.