Hi Bailer
I'd venture to suggest that the Caravan, as a camera platform, would be better, in terms of loiter endurance,stability,service ceiling and the ability to carry a camera operator in the cabin, rather like the old "photo" Doves.They were possibly thinking in terms of a survey aircraft rather than a pure tactical camera platform.Also, the Caravan's potential for quiet, night surveillance was evaluated, which paved the way for the Defender and it's role.Incidentally, the Marchettis were used to take photos for archaeological purposes.Also,an Italian-registered Learjet was hired in to survey the entire island for an update of the National maps and it operated out of the Don for about a week, flying a grid pattern over the terrain.
regards
GttC