object after flipping over. Theoretically, it is
sufficient that a scale is present and fully
visible in two photographs of one set only, as
long as it does not move relative to the
specimen between them, provided these two
photographs align with the rest of the set.
However, more photographs should be taken to
be on the safe side. Scales should also always
be included in the setup for the second (and
any further) set of photographs, in case the
multi-chunk method must be used if the one chunk
method fails (see below).