User`s guide

READOUT MODES
SDK SECTION 3
Page 32
Image
In Image mode the CCD is operated much like a camera. In this mode you get a measured value for each
pixel on the CCD, in effect allowing you to ‘take a picture’ of the light pattern falling on the pixel matrix of the
CCD. To prevent smearing the image, light must be prevented from falling onto the CCD during the readout
process. Please refer to
SECTION 8 - SHUTTER CONTROL for further information.
Figure 6: Image mode
To reduce the file size and increase the speed of readout it is possible to specify a sub-area of the CCD to be
read out. It is also possible to bin pixels together horizontally and vertically to create super pixels.
To set up a “Full Resolution Image” acquisition you need to call the following functions:
SetReadMode(4);
SetImage(1,1,1,1024,1,256);
To acquire a sub-area with lower left co-ordinates of (19, 10), with binning of 4 in both the horizontal and
vertical directions, and 100x16 pixels in the acquired image you would call the SetImage function with the
following parameters:
SetImage(4,4,19,118,10,25);
By a process of binning charge vertically into the shift register from several rows at a time (e.g. 4) and then
binning charge horizontally from several columns of the shift register at a time (e.g. 4) the ANDOR SDK
system is effectively reading out charge from a matrix of super pixels which each measure 4 x 4 real pixels.
The result is a more coarsely defined image, but faster processing speed, lower storage requirements, and a
better signal to noise ratio (since for each element or super pixel in the resultant image, the combined charge
from several pixels is being binned and read out, rather than the possibly weak charge from an individual
pixel).