Hasselblad Flextight 848 - Manual (Page 22)

White Calibration for Reflectives
The Flextight scanner uses a white reference to make sure that all
elements in the scanner's CCD react consistently to light brightnesses.
The scanner has been calibrated from the factory, and the calibration
data is stored in the scanner’s flash PROM.
As the scanner ages, the properties of the light tubes may change
slightly. Therefore, you must redo the white calibration every six months
or so and immediately after changing the light tubes.
Use procedure below to make White Calibration:
1. Find the white calibration sheet that came with your scanner. It is a
square white piece of paper (219 x 219 mm (8.6" x 8.6")).
If you have lost the white calibration sheet, then you can use a flat
(non-textured), perfectly white piece of paper of the same
dimensions.
2. Your scanner came with several clear plastic layers for the reflective
original holder. If you have used the reflective holder before, make
sure that there are no finger prints or other marks on the plastic
layer. Replace the layer with a new one if necessary.
3. Align the top edge of the sheet with the dotted line near the top of
the original holder (see Figure 6 opposite). Align each side of the
target with the edges of the original holder.
4. Select White Calibration from the Maintenance window. The
External White Calibration window appears.
User's Guide - Flextight 848
English
Hardware Reference - Flextight 848
22
Calibrating the Scanner