Originally Posted by
DanK
Speaking pedagogically, not photographically, you can't demonstrate the impact of three variables with one constant (one photograph). There is no way for a novice to see the effect of even one of these from a single photograph. If the point is to show them variables that matter, I think you need to show pairs of photographs, or even larger sets, for each variable. To demonstrate the effect of focal length, for example, requires showing the same framing of the same image with different focal lengths.
Also, I was puzzled by your omission of lighting. When I looked at the image before reading your text carefully, I assumed you were focusing (no pun intended) on that variable.
Providing sets that vary along one variable has a benefit above and beyond demonstrating the impact of that variable. It also allows them to think about their own choices for presentation, which might differ from yours or mine.