10x
Objective
nWithout
disturbing the focus, bring the 10x objective into position. Do NOT hold the
objective lens!
nMost
likely, you will only need fine adjustment to bring the section in focus. If
coarse adjustment is necessary, do this very carefully.
nMost
likely, you will also need to reduce light by using the iris diaphragm.
nNotice
that the ‘field of view’ is now smaller, and what you see is the central part
of the field that was seen with the 4x lens.