Pentax ZX-7 ZX-7 Manual - Page 68

66

S

SNOLLVI:13d0

033NVACIV

HARD-TO-AUTOFOCUS

SUBJECTS

The

autofocus

system

is

highly

precise,

but

not

perfect.

Depending

on

the

brightness,

contrast,

shape,

and

size

of

your

subject,

the

autofocus

system

may

not

operate.

In

such

a

case,

set

the

focus

mode

switch

to

[

MF

]

and

use

the

manual

focus

mode

to

focus

the

lens

on

the

sub-

ject

with

the

aid

of

the

matte

field

in

the

viewfinder

(see

page

65).

Subjects

which

may

fool

the

autofocus

system

include:

a)

Extremely

low

-contrast

subjects

such

as

a

white

wall

in

the

autofocus

frame[

[

3].

b)

Subjects

which

don't

reflect

much

light

in

the

autofo-

cus

frame

[

C

3].

c)

Subjects

which

are

moving

too

fast.

d)

Multiple

subjects

in

the

foreground

and

background

of

the

autofocus

frame

[

C

].

e)

Subjects

positioned

against

reflected

light

or

strong

backlight

or

with

extremely

bright

backgrounds.

Using

a

Polarizing

Filter

When

using

an

ordinary

polarizing

filter;

the

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

CIR-

CULAR

POLARIZING

FILTER

for

proper

autofocus

operation.

Notes

on

accessories

The

following

conditions

do

not

allow

autofocusing

or

manual focusing

with

the

in

-focus

indicator

in

the

viewfinder.

Use

the

manual

focus

mode

to

focus

on

the

subject

with

the

aid

of

the

matte

field

surrounding

the

autofocus

frame.

a)

When

using

special

effect

filters

or

"Magic

Image

Attachment"

or

"Stereo

Adapter".

b)

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

(4.9ft),

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

in

-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.

•

The

FA

Soft

85mm

f/2.8

lens

is

not

required

above

pro-

cedures.

Pentax ZX-7 ZX-7 Manual - Page 68

manual focusing

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