Nikon LABOPHOT-2 Manuel d'instructions - Page 21

Parcourez en ligne ou téléchargez le pdf Manuel d'instructions pour {nom_de_la_catégorie} Nikon LABOPHOT-2. Nikon LABOPHOT-2 33 pages.

V . M A N I P U L A T I O N

O F E A C H E L E I V ] E N T

6 ) U s e o f F i e l d D i a p h r a g m

The fie d diaphragm s used for determlning lhe i um nated area on

the spec men The s ze of the dlaphragm is adlusted by manip! at ng

t h e f e d d a p h r a g m c o n t r o r n g . S t o p p i n q d o w n t h e d i a p h r a q m t o

such an extent that the circqrfglelcc qtlh€ lllulll q

circumscribes or inscribes that oJ the evepiece field ol y!€tq s

recommended for genefal microscopy f a w der area than requ red

s l u m i n a t e d , e x t r a n e o u s l L g h t w

l e n t e f t h e f e d o f v e w , c a u s n g f l a f e

n the image and owerng the coftrast Therefore, especaly n

pholom crography, the proper adl!rstrnent of the {eld d aphragm s

very lmpofiant Generaly, good resu ts w ll be achleved when the

d aphragm s stopped down io such an extentthatthe d ameterofthe

luminated area is s ightly afger than the d agonal of the f m format

7 ) U s e o f C o n d e n s e r A p e r t u r e D i a p h r a g m

The condenser aperlure dlaphragm is provided for adjust ng the

fumerica ape{Lrfe (N A.)of the !l !m nating system oi lhe

, - . , -

t 6 . . T m n e 5 e r e o . , o

, . i "

i m a g e . c o n t r a s l , d e p t h o f f o c u s . a n d b r g h t n e s s .

Stopp ng down the aped!re diaphragm w ll ower the resolut on and

b f g h t n e s s b L r t n c r e a s e t h e c o n t r a s t a n d d e p t h o f l o c u s . I n g e n e r a .

when lt is stopped down to 70% to 80% of the numerical ape4llq

of the obiective, a good lmage of appropf ate contrast w I be

obtained (F g. l 1 )

To adlLrst the s ze of the condensef aperture d aphragm, man pu ate

t h e d a p h r a g m c o n t r o r i n g r e i e r r n g t o t h c c o n d e n s e r ' s N . A . s c a e .

o r a f t e r r e m o v n g t h e e y e p i e c e l f o m

t h e e y e p e c e t u b e , a d l ! s t t h e s z e

of the d aphfagm, observ ng the image of the diaphragm that s

vis b e of the br ght c fcle of the ex l pupilon the ins de ofthe objective

Slopping down the apenure diaphragm too tar w I o\/er the

reso v ng power Therefore, it ls recommended not lo slop down the

aperture to a s ze sma ler than 60% of lhe N A oftheobjectve n

, 6

6 , 6 0

. h o ,

o o o , .

g o r - l o

1 1

Size oithe condenser aperture diephr.gm

F i 9