A very old-fashioned club of photographers, who don't use any kind of digital, modern devices, is shaken by some murders. All evidences for the murderer, however, refer to Barnaby himself...
It is quite funny because it seems as if the episodes about pictures always deal with an Inspector Barnaby who isn't allowed to investigate after it seems to be clear that he could have been responsible for the murders. But he is still not discouraged to carry on. The same happened in an earlier episode, "Painted in Blood", with Sergeant Troy, which also turned out to be amusing. The people, who instead investigate then, are, of course, entirely incompetent to solve the murders.
This time, the plot is set in one of the many, uncountable villages of Midsomer, around several photographers who fight against digitalisation (or at least some of them). The time stopped a long time ago, more old-fashioned would never be possible. However, it could be seem as a pity that the conflict about the course of time and their views is not fully solved.