Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

Unger says that this is actually Z-309.

 I got this from a DVD I have called Image of an Assassination.

I was urged to get this because it's the clearest, sharpest version of the Z film that there is. 

So, I was watching it, and I stopped it when Mary was closest to passing out of view to the left. You notice that she is already partially cut off in this view.

At normal speed, or even in slow-motion, it's moving rapidly, and it's hard to capture that last good frame of her. It took me several tries to get this, but I do consider it the last good frame. Her image starts blurring after this. 

Now, you'll notice that the frame isn't marked. So, I just guessed at the frame number. 

But now, I have checked it with Costella, and I would say that it matches best to Z-310.

In the frame I put up from the DVD, they cropped out the sprocket part of the film. That was their doing, not mine. But, it's not 309 because in 309, you can see her whole shoulder.

 So, my best guess, now, is that it was Z-310, and I stand corrected for having said Z-312.