He started with a demonstration of some of his earlier attempts at macro photography using a praying mantis and a Mexican red-kneed tarantula as subjects.
Using these images, he was able to demonstrate the problems he encountered with the limited depth of field inherent in this type of photography.
The solution was to take multiple imaged of the subject whilst shifting the focus slightly in order to take a series of photographic slices of the subject to be processed using a variety of computer programs from the ubiquitous Photoshop through to software written specifically for focus stacking.
For this part of the demonstration he utilised a program called Helicon which not only processed the images, but also allowed the camera to be tethered to a computer to enable to software to calculate the near and far focus points and calculate the focusing points as defined by the user.
Using the skills learned in macro photography, Alan was then able to transfer the technique to landscape photography to ensure pin sharp focusing from front to back.
These skills and techniques set the stage for our next meeting when John REDPATH has volunteered to give a talk on his adventures in macro photography.