Leica Biosystems M205A - Manual (Page 79)

Leica M series Manual 79
Light intensity control
• Please observe the user manual—in
particular, all safety regulations—from
the manufacturers of the light guide and cold
light source.
Switch on the cold light source according to ★
the manufacturer's user manual and adjust
the brightness.
Transmitted-light control
The TL BFDF transmitted-light base has a poten-
tiometer that switches the light from "bright
field" to "dark field".
Bright field
Bright field is suitable for examining translu-
cent objects featuring contrasting structures.
The object is directly illuminated from below
and is seen in its natural colors against a bright
background.
Turn the control as far as it will go towards ★
"BF" ("bright field").
Dark field
In dark-field illumination, a ring illuminator is
used in such a way that the direct light
does not reach the objective without a speci-
men. Only the structure of semitransparent,
opaque objects disperses the light, making the
object visible against a dark background.
Turn the control as far as it will go towards ★
"DF" ("dark field").
Transmitted-light Base TL BFDF: Operation
Fingertip with bright field illumination Identical subject with dark field illumination