Olympus DP70 User Manual page 24

In this dialog box, check
whether correction
images of the Dark or
the Flatfield type, are
available.
Definition "Shad- Every optical system with a camera and microscope creates, even when the devices
ing"
have been set up very carefully, image inhomogeneities in the illumination of the
sample. These are called shading.
The left illustration
shows an image where
the online shading
correction has not been
activated. In compar-
ison to the image on the
right, one can notice the
inhomogoneities in the
illumination.
For a shading correction, the shading will first be determined in order to be able to
make corrections to the acquired image. To determine which shading there is in the
image, two types of correction images will be acquired:
Dark correction The
image
Here, pixels with different brightness resulting from noise or different sensitivity of
individual pixels on the camera chip can be corrected by the correction image. The
Dark correction image
once. It is valid for all objectives.
Flatfield correction On the
image
out a sample will be shown. An individual correction image must be made for every
objective and for every resolution of your camera.
Dark correction image is an acquisition during which no light falls on the camera.
is characteristic for each camera and needs only be acquired
Flatfield correction image the illumination of the complete optical system with-
Camera settings