|A picture I made today by method 2 explained further on|
There are two ways to focus a camera on the aforementioned focus planes (incidentally, those same planes are parallel to the camera's CCD capturing element plane, if you haven't guessed it yet):
1. Keep the camera immovable on a steady tripod, pointing at the object, and use the lens ring to focus and shoot frames on a number of equally spread imaginary planes across the lens axis of the camera.
2. You focus at one extreme of the object (say, its front end), and then micro-displace the camera at new focus plane positions, for a discrete number of incremental steps, at which points you obviously shoot subsequent new frames, until you reach the object's other extreme (say, its back end).
|I added those arrows on the 454's knob for better control|
To systematically focus on those incremental planes by precision turning of the focus ring, one does need indeed to tether the camera to a computer and control it with a dedicated app (like Helicon Remote). It's virtually impossible to obtain similar increments between focus planes by manually turning the focus ring. If you can manage to do it, then you're a champ. Also, the measurement scales typically depicted on focus rings are not terribly accurate to be used for such micro adjustments. For all practical reasons, only computers could manage this precision focusing properly. So, for method 1 you really need to tether your camera to a computer and control the shoot with an app. Furthermore, most people own cameras that are not readily supportable by the available tethering software (eg. Helicon Remote). So, you could really be left out in the cold...
|Manfrotto 454 Micrometric Positioning Sliding Plate|
In other words, method 2 only requires you to invest in a sliding plate (plenty of solutions for a few bucks, less than 100 anyways) and any camera of your liking, without bothering about availability of tethering control apps. The FS you can eventually do with any dedicated app (available from free, via shareware, and a few good commercial solutions like Photoshop and Helicon).
|Camera setup for shooting the coins|