StarDot Technologies netcam XL - Manual (Page 42)

Page 42 NetCam XL
Chapter 5 NetCam Lenses
The Focus Ring
NetCam ships with a pre-focused lens. Most lenses available for
NetCam also have a focus ring which allows you to focus the lens for a
closer subject. The focus ring may be marked in meters:
0.2m -- 0.3 -- 0.4 -- 0.5 -- 1.0 -- oo
The oo stands for infinity. When NetCam leaves the factory, the infin-
ity setting is back-focused for infinity. Turning the focus ring to 0.5 meters
will yield a focus of half a meter. Turning it back to the infinity symbol will
yield an infinite focus again.
Some lenses will not have the numerical markings -- they may be
marked only with “near” and “far”. The “far” setting is infinity and the
“near” setting is the closest the lens will be able to focus, which varies
from lens to lens.
The Iris Ring
Most lenses available for NetCam come with a manually adjustable
iris ring. In indoor lighting situations, you will usually want the iris open
to its fullest position. In outdoor lighting, you will almost always want the
iris set to its smallest position (ƒ16 or smaller, pinhole-sized). The iris ring
is usually marked in ƒ-stops:
1.3 -- 4 -- 8 -- 16 -- C
The C stands for closed. In this example, the 16 setting is the smallest
marked iris opening and 1.3 is the largest. You can set the iris to settings in
between the marked numbers (setting it between 16 and C would result in
a setting closer to ƒ22, which is even smaller than ƒ16).
Some lenses do not contain numerical iris markings, but will be marked
with “open” and “close”. You will need to look in the lens to see the size
of the iris when placing NetCam outdoors. Adjust the iris ring until the iris
opening or aperture is the roughly size of a pinhole. We strongly recommend
you tune the iris by following the instructions in section 4.1.
Changing Lenses
Change lenses usually requires a back focus adjustment of the new lens.
Back focus is the adjustment of the chrome ring that the lens is screwed
into. Follow these steps when replacing a lens.
1. Unscrew the original lens from the chrome back ring and com-
pletely remove it.
2. Determine if your lens is C-Mount or CS-Mount. If you ordered