Nikon Speedlight Instruction Manual page 16

S H O R T - R A N G E
A N D C L O S E - U P L I G H T I N G c o n t i n u e d
Switch on the power switch on the main unit. The
neon ready lamp will light up when the unit is ready
to fire.
Depress the lens aperture opening button on the right
side of the ringlight. This opens the lens diaphragm to
full aperture and lights the focusing lamp.
To remove the ringlight, depress the spring catch
on the ringlight and turn it clockwise.
N o t e : T h e 5 1 0 - v o l t p o w e r p a c k S D - 3 c a n n o t b e u s e d a s a
p o w e r s o u r c e f o r t h e r i n g l i g h t S M - 1 . E x t e n s i o n i s n o t p o s s i b l e .
Exposure Determination
The exposure calculating diagrams on page l7 are used
to find the correct aperture for lenses from24 mm to
the l05mm. The diagrams are based on exposure in-
dexes for ASA 25 film at full power or for ASA 100
film at ll4 power. F-numbers are calculated taking
into account the lens extension.
For example, if the lens used is the Micro-Nikkor-P
Auto 55mm f/3.5 with ASA 25 film at distance of
287mmfrom the film plane at full power, the diagram
gives f/12 as the correct aperture.
For combinations other than ASA 25 full power or
100 film at Il4 output, use the f-number indicated
by the diagrams and add or subtract the exposure
factor given in table below for the conrbination in use.
Exposure Factors for Film Speeds (ASA)
( A s s u m e d a s a s t a n d a r d ( = 1 ) f o r r h e l r g h l o u l p u t F U L L a n d t h e f ' l m s p e d A S A 2 5 )
L i g h t - O u t p u t S e l e c t o r
S w i t c h
Film spad
(ASAI
Fctor
Li*rt output FULL
LiCrt oulput 1/4
25 1 X
4X (lncrro|. 2
n
l/1.3x (D.crcd
1/3 3tool 3.2X llncras l-1/3 nop3l
50 t/2X lDlcre.s I nopl
2X (lncrlE
I rtool
g 1/2.6X lD.cr.s 1-113 t l.6X llncrr.r2l3elopl
r @
l/4x lD.crulr
2 rtoFl
t x
126
1/5.2X (D.crora 2.1/3 noptt
1/1.3X (Drcr.n
l/3.
160 ll6.4X lDr,scg2-2132
1/1.6X (Dccraa 2/3 nop)
2(n
1/8X (Oscrrr. 3 nop3l
1/2X (D.cr.Gr I noo)
4{Xt l/t6x lD.6cE 4 l/4x lo.croD
2 rtoF)