Olympus i-SPEED 2, Instructions Manual

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Nomenclature & Functions
17
i
--SPEED LT,
i
--SPEED 2
12. Back Focus Control
It is sometimes necessary to adjust the distance between the
C--mount face and the image sensor to accommodate lenses
from different manufacturers and lenses with different optical
tolerances. The Olympus
i
-- SPEED LT,
i
-- SPEED 2 has a back
focus assembly located in the front of the unit to permit this
adjustment.
To adjust the back focus, screw a C--mount lens into the
C--mount in the normal way. Turn the locking ring anticlockwise
(when viewed from the front) to unlock the C--mount thread ring
then rotate the lens to adjust the back focus as required -- a
series of ‘click’ positions will be felt. When complete, the
adjustment should be left in one of these ‘click’ positions and the
locking ring rotated clockwise to lock the C--mount thread ring in
position.
C--mount lens
Locking ring
As a guide, the correct setting of back focus is obtained by
pointing the camera at an object a known distance from the lens,
preferably an “infinite” distance. The scale on the lens is then
used to set the focus ring to this distance. The back focus is
then adjusted to obtain the best image.
13. Mounting Holes
The base of the unit is fitted with 5 standard
¼
” UNC mounting
holes. It is recommended that the central hole is used for
mounting the camera (e.g. to a tripod) and the other holes may
then be used to mount light--weight accessories to the camera.
It is important that the
i
-- SPEED 2 HG camera is mounted using
the four outer mounting holes when used in high--G applications.