Pentax PZ-20 PZ-20 Manual - Page 49

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HARD-TO-AUTOFOCUS

SUBJECTS

The

autofocus

system

is

highly

precise,

but

not

perfect.

Some

subjects

may

not

focus

as

you

wish. In

such

a

case,

use

the

focus

-lock

technique

on

a

subject

near

the

actual

one

and

equidistant

from

the

lens,

or

set

the

focus

mode

switch

to

IMF]

and

use

the

manual

focus

mode

to

focus

the

lens

on

the

subject

with

the

aid

of

the

matte

field

in

the

viewfinder.

Subjects

which

may

fool

the

autofocus

system

include:

a)

Extremely

low

-contrast

subjects

such

as

a

white

wall

in

the

AF

frame

b)

Subjects

which

don't

reflect

much

light

in

the

AF

frame

c)

Subjects

which

are

moving

too

fast

dl

Subjects

with

horizontal

lines

or

with

finely

complex

or

detailed

patterns

in

the

AF

frame

e)

Multiple

subjects

in

the

foreground

and

background

of

the

AF

frame

f)

Subjects

positioned

against

reflected

l

ight

or

strong

backlight

or

with

extremely

bright

backgrounds

Notes

on

accessories

The

following

conditions

do

not

allow

autofocusing

or

manual

-

focusing

which

uses

the

in

-focus

indicator

in

the

viewfinder.

Use

the

manual

-focus

mode

to

focus

on

the

subject

with

the

aid

of

a

matte

field

surrounding

the

AF

frame.

a)

When

using

special

effect

fi

lters

or

"Magic

Image

Attachment"

or

"Stereo

Adapters"

b)

When

using

an

ordinary

polarizing

filter:

a

half

mirror

incorporated

into

the

autofocus

system

reduces

the

effectiveness

of

the

autofocus

function

when

used

in

combination

with

an

ordinary

polarizing

filter.

Use

a

circular

polarizing

filter

for

autofocus

operation.

cl

When

using

Extension

Tubes

or

an

Auto

Bellows

for

close-up

photography

Note

on

the

SMC

Pentax

F

SOFT

85mm

f/2.8

lens

When

shooting

at

a

distance

closer

than

approx.

1.5m,

set

the

lens

to

a

manual

f-stop

setting

between

f/2.8

and

f/4.5.

A

smaller

aperture

(f/5.6

to

f/32)

may

cause

the

autofocus

system

and

the

viewfinder's

focus

indicator

to

malfunction.

To

remedy

this

problem,

temporarily

set

the

lens

to

f/4.5.

After

focusing

on

the

subject,

lock

focus,

and

set

the

lens

to

the

required

f-

stop.

45

2

SNOI1VU3d0

Pentax PZ-20 PZ-20 Manual - Page 49

Hard-to-autofocus, Subjects

Page 49 highlights