I haven't been able to find a better program to project images for tracing with my projector. But if I zoom in or move the bars on the side of the screen, it moves the image. It takes me a while to re-align the image, and I was hoping there was a way to reset the sliding bars and the zoom percentage.
As of now, I just have to close the whole document and reopen it, and then it reorients, or I draw registration dots on the photoshop image and trace the dots onto the wall, so if photoshop shuts down, I can realign the image using the dots, but this isn't ideal.
If you're projecting the full image at once, then you can keep the image in the same place within Photoshop by maximizing the Photoshop application frame (clicking the green circle in the upper left on macOS or clicking the icon of a single rectangle in the upper right on Windows) and then fitting the image to the frame, View > Fit on Screen or Command + 0 (macOS) or Control + 0 (Windows).
If you're zooming in and projecting at various locations, you could add guides to help with registration by turning on the Ruler (View > Ruler) and dragging the guides out from the ruler over the canvas. You'll want to note what the percentage of zoom is. You can see it in the tab to the right of the filename or in the Navigator (Window > Navigator). You can enter the zoom amount in the lower left of the Navigator panel.