Quantum Instruments Qflash TRIO Basic Flash for Cameras - Manual (Page 26)

To solve this problem use the Flash Sensor Limit.
∞ - No limit placed on sensor distance
5ft / 2m, 10ft / 3m, 15ft / 4m, 20ft / 6m
When the Flash Sensor Limit is set to
∞ the flash will produce the
desired f/# for a subject within the flash’s minimum and maximum flash
distance.
With Auto Sensor Limit turned on, a ‘Limit’ indicator is activated. After a
flash, if the subject’s distance exceeds the sensor limit currently set (5,
10, 15 or 20ft. / 2, 3, 4, 6m) the word ‘Limit’ will appear in the display.
Three beeps and/or 3 blink warning may also occur (if those features are
set in Options). If the subject is within the current Sensor Limit normal
exposure indicators (OK, Undr, Over) will apply
.
11.6 Using the Auto Sensor Limit
The flash Sensor Limit function essentially cuts down on the distance
that Qflash attempts to illuminate. When using Sensor Limit it is no
longer necessary for the subject to be centered in the frame, as long as
the subject is in the Sensor Limit. See the examples shown below.
Open field
The subject is located 15 feet from the
camera. The background is an open field
in a park. By setting the Sensor Limit to
15 feet, the flash will read only the light
reflected back from the subject area
within 15 feet, ignoring anything further.
Two subjects separated by a gap
Sometimes two subjects are
separated by a gap. When this
occurs the sensor is ‘looking’
between the two subjects and may
miss them. The Sensor Limit will
correct for this by reading only the
light from objects within the limit
set, in this case, 15 feet. The light
from objects further away will be
ignored.
24
BACKGROUND
SUBJECT SUBJECT
15 FEET
TRIO IN AUTO WITH SENSOR
LIMIT SET TO 15 FEET
SUBJECT
NO BACKGROUND
(OPEN FIELD IN PARK)
15 FEET
TRIO IN AUTO WITH SENSOR
LIMIT SET TO 15 FEET