Video | Fixed Focal-length Lenses
Fixed Focal-length Lenses
www.boschsecurity.com
u High quality optics
u DC-iris types (direct drive)
u Reliable, robust DC-iris mechanism
As CCTV cameras becomes more reliable and
maintenance-free through the use of solid-state
charge-coupled device (CCD) technology, the lenses
also need to have the same high standards of quality
and reliability.
The range of Fixed Focal-length Lenses meets these
tough requirements by providing long and reliable
operation with no maintenance. Comprising DC-IRIS
and video-iris types, the lens range from wide-angle to
telephoto to cover virtually all applications in CCTV
observation systems.
Functions
Designed for easy installation onto a wide variety of
CCTV cameras, they are available for cameras with
1/3-in. and 1/2-in. image sensor formats. The extent of
the range of lenses means that an installer will always
be able to select the most appropriate lens for both
camera and application.
DC-iris and video-iris lenses include manual focus
adjustment types and can be used in applications with
widely varying lighting conditions. These lenses are
available with a standard 4-pin connector.
u 1/3-inch and 1/2-inch formats
u Standard CS-mounts
Installation/configuration notes
Choosing the correct lens
There is a simple relationship between the required
field of view and the focal length of the lens to be
used (see Field of View figure).
To determine this:
• Estimate or measure the maximum width “W” of the
field of view.
• Estimate or measure the distance “D” between the
camera and the object to be viewed.
• For 1/3 in. lens, use Graph 1 and for 1/2 in. lens use
Graph 2. Find the point on the graph for the lens and
the sensor format corresponding to the “W” and “D”
co-ordinates. To ensure complete coverage of the
object, select the lens indicated by the line above this
object. Normally, for optimum coverage of the field of
view, 1/3 in. and 1/2 in. lens are used with camera
heads with 1/3 in. and 1/2 in. format sensors
respectively. However, 1/2 in. lens may be used with
1/3 in. cameras but the outer areas of the field of
view of the lens will not be seen by the sensor.
0 10 20 30 40 50 60 70 80 90 100
100
90
80
70
60
50
40
30
20
10
0
2.8 mm
4.0 mm
6.0 mm
8.0 mm
12.0 mm
3.7 mm
1
2
0 10 20 30 40 50 60 70 80 90 100
100
90
80
70
60
50
40
30
20
10
0
6.0 mm
12 mm
3.7 mm
1
2
36.3
1.4 3
5.6
.22
33.9
1.3 3
36.8
1.4 5
43.5
1.71
43.5
1.71
36.8
1.4 5
5.6
.22
33.8
1.3 3
34
1.3 4
2 | Fixed Focal-length Lenses
4-pin DC-iris Connector (Front view)
Pin 1: Damping coil –
Pin 2: Damping coil +
Pin 3: Driving coil + (open)
Pin 4: Driving coil -
Graph 2 – Field of view (1/2-inch cameras)
1 Object width (m)
2 Object distance (m)
Field of view
Graph 1 – Field of view (1/3-inch cameras)
1 Object width (m)
2 Object distance (m)
Dimensions LTC 3314/21 LTC 3334/21 & LTC 3344/21
In mm (inch)
Dimensions LTC 3214/20, LTC 3234/20 & LTC
3244/20
In mm (inch)
Ordering information
LTC 3314/21 Fixed Focal-length Lens
1/3-inch, 2.8 mm, direct drive, CS-mount F1.2-100, 4pin
Order number LTC3314/21
LTC 3334/21 Fixed Focal-length Lens
1/3-inch, 4 mm, direct drive, CS-mount F1.2-100, 4-pin
Order number LTC3334/21