Start by making sure you have that "Emulate Numpad" enabled. Then, turn off "Lock camera to view" and press 5 twice. This should put you into ortho view, then back to 3D navigation. When I did this, you can see where the camera is relative to the object.

From here, move your viewport until it's at the desired distance and angle and press Ctrl + Alt + 0 - this will set the camera to your view. When I did this, it appeared waaaaay zoomed in, so scroll out with the mouse wheel until you see the box:

However, when I placed it in a spot that looked "correct" relative to your reference photo, you can see where the camera is. I'm not sure why this is happening, other than the object(s) you have are very small. Adding a new camera had the same effect. It might not be a problem at all though, because the render comes out exactly like what is shown in the box - at the very worst, you could scale up the objects if necessary.
