Phytec FireWire-CAM-001, Manual

Page: 46 / 86

FireWire-CAM-001 / 002
40 
PHYTEC Meßtechnik GmbH 2005 L-661e_1
3.2 Connecting the Lens
The camera supports lenses with C-Mount or CS-Mount connectors.
Refer to section 2.4 for instructions on connecting the lens.
Hints for Selecting the Lens
In order to take full advantage of the quality and the features of the
camera, it is important that you select a lens that is optimized to your
application. In the following section we have provided some helpful
hints on how to proceed in the selection of a suitable lens.
•
Focal Length
With the focal length you determine the visible screen window, or
image portion captured by the camera.
The focal length depends on the size of the CCD chip, the distance
from the object and the focal length of the lens being used.
The screen window should be optimized so that the object being
captured is always fully visible on the screen, and also so that the
amount of unused screen space surrounding the object is
minimized. Otherwise the object would be displayed unnecessarily
small and the camera’s resolution would not be fully utilized.
The FireWire-CAM-001/-002 are both equipped with a ¼“ –
CCD-sensor. The following formula can be used to calculate the
required focal length f from the desired frame width B and the
distance between the object and the lens (L) (all values in
millimeters):
L
B
mm
f
⋅ =
6 . 3
Round the resulting value up to the next available focal distance.
This will give you a slightly bigger screen window than necessary
but it ensures that the entire object will be captured on the screen.