For successful imaging in Surveyor it is important to setup the camera settings such as exposure, white balance and shading correction prior to scanning a sample. Failure to do this can result in a checkerboard shading effect for example, or unnecessarily long scanning times, or other such issues. It is desireable to reperform this setup:
- For each new slide.
- Whenever any camera settings are changed.
- Or whenever any change to the optical path takes place, ie. condenser, aperture changes, etc.
To do this you can apply the following sequence as a simple guide to basic image setup. Your particular camera model may have slightly different dialog layouts from the one shown below.
- Relocate the stage to a blank field using the stage move-to-xy tool, ie. no specimen should be visible in the live image window.
- Open the camera image setup dialog.
Adjust the exposure and/or gain in such a way that the exposure histogram is moved to the right edge of the available space but not beyond this, otherwise over-saturation occurs.
Moved to the right edge of the exposure histogram:
We now have a reasonable exposure setting, necessary in order to perform an auto white balance. Select the Color Balance tab and click the White Balance button.
Before auto white balance:
After auto white balance:
The color channels of red, green and blue should now be aligned. Having done the white balance it may now be necessary to repeat the exposure (and/or gain) and perform another auto white balance to incrementally improve these settings.
Finally click the Shading tab and click the Setup Shading Correction button. This will calculate a shading correction pattern in order to compensate for vignetting edge effects.
Shading correction can also help to reduce the prominence of dust and debris in the optical path, like this:
However it is recommended to service the microscope optics rather than rely on the shading correction for this, as some small effects may remain:
These steps will need to be peformed for each objective on the system.