Adjustment of the condenser diaphragm makes a big difference in the performance of the microscope, (a) shows the condenser diaphragm is too small, (b) about correct and (c) too wide open. Adjustment of the condenser diaphragm makes a big difference in the performance of the microscope, (a) shows the condenser diaphragm is too small, (b) about correct and (c) too wide open. The arrows show two adjacent Malassezia. These images, using the x 20 objective show the minimum effect, at higher and lower magnifications, the effects can be more extreme Stephen Shaw In Practice 2016;38:12-16 Copyright © British Veterinary Association. All rights reserved.