Pentax ZX-10 ZX-10 Manual - Page 37

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CI3ONVAOV

68

(8)

ADVANCED

OPERATION

FOR

THE

BUILT-IN

FLASH

(RTF)

When

using

the

Smart

Picture

Mode

or

Picture

Mode

•

The

camera

automatically

chooses

an

optimum

com-

bination

of

shutter

speed

and

aperture

according

to

the

subject

brightness,

allowing

you

to

take

a

flash

photograph

with

ease.

•

The

shutter

speed

automatically

changes

to

approxi-

mately

1/100

sec.

or

to

a

slower

speed

which

does

not

cause

camera

shake.

The

slowest

shutter

speed

depends

on

the

focal

length

of

the

lens

fitted

to

the

camera.

When

a

Pentax

non

-AF

lens

is

used,

the

cam-

era

uses

the

shutter

speed

of

1/100

second.

When

using

the

Shutter

-Priority

AE

Mode

•

Shutter

speeds

slower

than

1/100

of

second

can

be

set.

•

In

this

mode,

the

aperture

automatically

changes

ac-

cording

to

the

ambient

brightness,

making

flash

pho-

tography

easy.

Calculating

the

flash

effective

distance

accord-

ing

to

the

camera

-to

-subject

distance.

Maximum

flash

distance

=

Guide

Number

-

Selected

aperture

Minimum

flash

distance

=

Maximum

flash

distance

±

5*

When

the

distance

to

the

subject

is

less

than

0.7m

(2.3ft),

the

flash

cannot

be

used.

If

the

flash

is

used

within

that

distance,

it

causes

vignetting

in

the

picture

corners,

light

is

distributed

unevenly

and

the

picture

may

be

overexposed.

•

The

value

5

used

in

the

formula

above

was

obtained

from

the

built-in

flash.

The

guide

number

(GN)

depends

upon

the

film

speed

used

as

shown

below.

ISO25

-

GN5.5

ISO200

-

GN15.6

ISO50

-p

GN7.8

ISO400

-

GN22

ISO100

-p

GN11

If

an

ISO100

film

is

used

at

an

aperture

of

f/2.8,

the

flash

effective

distance

is

obtained

as

follows:

Guide

Number

(11)

f/2.8

=

3.9m

3.9

-4-

5

=

0.8m

When

using

the

Aperture

-Priority

AE

Mode

•

In

this

mode.

the

shutter

speed

automatically

changes

with

the

ambient

brightness,

making

flash

photogra-

phy

easy.

The

shutter

speed

changes

in

the

range

of

1/100

sec.

to

a

slower

shutter

speed

which

does

not

cause

camera

shake.

The

slowest

shutter

speed

de-

pends

on

the

focal

length

of

the

lens

in

use.

The

shut-

ter

speed

of

1/100

sec.

is

automatically

set

when

a

Pentax

non-autofocus

lens

is

in

use.

Metered

Manual

Mode

•

When

using

the

built-in

flash

in

the

Metered

Manual

Mode,

any

combination

of

aperture

and

shutter

speed

slower

than

1/100

can

be

set.

In

this

mode,

the

exposure

of

the

background

can

be

controlled

by

the

manual

exposure

while

the

flash

properly

exposes

the

foreground

subject.

Thus,

the

flash

effective

distance

is

from

approx.

0.8m

to

3.9m.

Calculating

the

aperture

according

to

the

camera

-to

-subject

distance

Aperture

=

Guide

Number

±

Camera

-to

-subject

dis-

tance

If

the

calculated

aperture

value

is

different

than

an

indi-

cated

f-stop

on

the

aperture

ring,

for

instance

f/3,

choose

the

next

smallest

aperture

ring

number

(f/2.8

in

this

case).

Calculating

the

camera

-to

-subject

distance

in

the

Shutter

-Priority

AE

Mode

The

camera

-to

-subject

distance

can

be

calculated

using

the

above

mentioned

formula.

However,

in

the

Shutter

-

Priority

AE

Mode,

the

-camera

-to

-subject

distance

will

change

depending

on

what

aperture

is

set.

S

MIMED

z

0

O

m

9

O

Pentax ZX-10 ZX-10 Manual - Page 37

Advanced, Operation, Built-in, Flash

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