Nikon DIAPHOT 300 - Page 4

9. Dirt on Lens
Do not leave dust, dirt or fingerprints on the lens or lamp. Dirt or stains
on the lens or mirror will deteriorate image quality.
10. Focusing Knobs
Never attempt to turn the right-hand and left-hand focusing knob in
opposite directions at the same time as it will result in defects or damages.
An attempt to turn the coarse focusing knob further after it reaches its limit
will cause defects or damages. Never turn it forcedly.