Complex sentence: Since only the two outer images of the four images formed by each snap were mounted, using an unmodified Nimslo to produce stereo pairs results in a lot of film wastage and making prints is even more costly since half of them will be thrown away.
Split into simpler sentences: Since only the two outer images of the four images formed by each snap were mounted, using an unmodified Nimslo to produce stereo pairs results in wasted film. Making prints is even more costly since half of them will be thrown away.