14 – LSM 880 Training Guide
Acquisition Setup
The ‘Channels’ menu contains the three components used to dynamically control image quality. They are (1) Laser Power, (2)
Detector Sensitivity, and (3) Pinhole or Confocal Aperture Diameter. For further discussion on these parameters and how they
affect image quality please see ‘Understanding Image Quality’ starting on page 19.
Channels
Functions available in the Channels dialog:
Lasers
– controls laser power (%) and wavelength selection.
Pinhole
– confocal aperture diameter that controls optical section
thickness. Reports section thickness and pinhole diameter.
Gain (Master)
– controls the analog amplification voltage for the PMT (in
Volts). The higher this value the more sensitive the detector becomes to
the signal. Noise is also amplified by gain, albeit at a slower rate.
Digital Offset
– controls the dark current offset for the imaging system.
When scanning an image with all lasers off this value set to ‘0’ should
report background grey values close to/at 0 grey levels.
Digital Gain
– is a digital amplification of signal that is applied pre A/D
conversion. This amplifies signal at the same rate as it amplifies noise.
Leave this value set to 1 – there are other locations to control image
brightness that are more flexible and less destructive.
