... WFC3 Data Handbook > Chapter 6: Charge Transfer Efficiency (CTE) . ... 6.5 Dealing With CTE Losses In WFC3/UVIS Images . ... This chapter describes the various aspects of CTE losses in the WFC3/UVIS detector. The first section provides a general overview and compares CTE losses in WFC3/UVIS to those in ACS/WFC. The next section discusses the nature of WFC3/UVIS losses in more detail, focusing on how the mini-channel makes it possible to minimize CTE losses with a small addition of background. ...