I was working on a personal project and at some point I needed a fast transition of images. The idea was to create materials with those images and attach those materials to planes with the same size of the image.
For a large amount of images this is a very ungrateful job so I created a simple python script to do it. This is the result. As you can see is very simple.
I think I dont understand your question. The idea is: whenever the plane (photo) is not in front of the camera it has to be far enough so it doesnt appears in front of the camera. I have chosen [0,1000,0] as an arbitrary place for them to be. Then the animation goes like:
at the ith frame the plane is in [0, 1000, 0]
from the frame ith+1 to ith+N is in [0, 0, 0]
then, for the frame ith+N+1 goes back to [0,1000,0]