Here is a series of 6 images focusing on each of the 6 coins in turn Then combined with photoshop to yeild an over all increase in the Depth Of Field. The only other thing done to these photos was they were cropped in light room.
Process in Photoshop CS4 is as follows
File->Scripts->Load Files Into Stack. Check off the option to automatically align the images.

Then select all the layers, go to Edit->Auto-Blend Layers and select the option for Stacking. Also make sure the checkbox to correct color is checked.
Using this process compensates for any changes in FOV Really a pretty stright forward process.