I teach a very basic Intro to Graphic Design course using the Adobe Suite. In the section on photo retouching we talk about the clone stamp, healing brush, spot heal, and content-aware fill tools. In the past I've talked about the strengths and weaknesses of each one, but the problem I'm running into is that the spot heal and content-aware tools have gotten too good--good enough that I'm having trouble creating exercises that force my students to use the other, more manual tools.
Any suggestions? Has anyone done a project recently where only the clone stamp would do the job? Or should I give up and just accept that these are the modern tools and that knowing them is probably enough for an intro class? Extra points for an exercise that lets me sidestep the ethical considerations of photo retouching (we talk about it, just not at this time).