Pentax SF1 Manual page 46

• If the lens aperture ring is set at any f-number for the
selected exposure mode, the effective flash range is
determined by the selected aperture (G.N. 14
-r
f/4 =
3.5m), and the flash-sync shutter speed is set at 1 /100
sec.
• When a lens with a maximum aperture of f/2.8 or
smaller is used, the aperture display in the CENTIC
panel starts from that maximum aperture of the lens.
• The Program Flash system can be used in combination
with a Pentax-F or -A lens. Be aware that the RTF's
discharge may be cut off by wide-angle lenses or lenses
with a large diameter.
• When a Pentax-F lens that may cut off the RTF's
discharge is mounted (e.g., some zoom, telephoto and
macro lenses), the red flash-ready indicator [ i ] blinks to
warn the photographer. In this case, the shutter can be
released but the RTF will not discharge.
• Do not use a lens hood. The RTF's discharge is also cut
off within the distance of Im when a 35mm wide angle is
mounted, so do not use the RTF in such cases.
• Be aware that photographing a person straight on from
the front using a flash beyond a distance of 3m may
cause the "red-eye" phenomenon produced when light
reflects off the retinas. (This can be avoided by directing
the subject's gaze away from the camera.)
AF Spotbeam Projector
When using the RTF in a dark location, the AF spotbeam
projector automatically emits an infrared beam to assist
the auto-focus system.
The spotbeam projector can also be used in dim locations
where the auto-focus system may not work effectively.
• The AF spotbeam projector can be used only when the
focus-mode switch is set at the SINGLE position. It will
not work at any other position.
• The AF spotbeam projector's effective range is
approximately 1m to 4m. If flash illumination is unneces
sary, push down the RTF unit after the AF system
captures the subject in focus.
• The AF spotbeam projector does not operate for bright
subjects.
• If the [►^l indication appears, auto-focusing is
impossible. (See pages 33 to 35.)
• When the AF400FTZ's AF spotbeam projector is used,
the AF spotbeam projector built into the camera does
not operate.
•
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