Instruction manual
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Using as a simplified illuminance
meter
Attach the Flat Diffuser (optional accessory), to the meter. Take a reading
of ambient light in AMBI mode by holding the Flat Diffuser parallel to the
surface you want to measure, then read the EV value from the meter. Now,
look up the approximate illuminance from the EV-lx conversion table on the
next page.
● Film speed is set to ISO100 and display units are set to EV.
● If the instrument has been recalibrated, set it back to the standard
setting of 0 using Alt mode.
★ If you need to measure illuminance precisely, use the MINOLTA
DIGITAL ILLUMINANCE METER T-10, which is designed specifically for
this function.
How to read the EV-lx conversion table
The EV-lx conversion table lists the integer component of EV values
vertically and the decimal fraction components of EV values horizontally.
For example, if the meter displays a reading of EV 10.2, the row for the
integer 10 and the column for the decimal 0.2 intersect at 2900 lx, the
corresponding illuminance value.
Using the brightness difference function of the instrument, the lighting ratio
can be read with an accuracy of 0.1 stops.
Alternatively, instead of storing the readings in memory, as explained in
step 7 on the previous page, the following method can be used:
7
Press the S/A/H button. A is displayed on the data panel, and
the exposure reading for the main light source is fixed.
8
Take a reading with the Flat Diffuser facing towards the fill
light source. While holding down the measuring button, the
difference (or lighting ratio) between the fill light source
exposure and main light source exposure, which was fixed in
step 7, is displayed directly on the digital readout. Read the
value.
The lighting ratio of main light source to fill light source can be calculated
from the following table.
Table for determining lighting ratio
Brightness differences Brightness ratio between main light source
(exposure differences) and fill light source (lighting ratio)
+1.0 (1 stop) 2:1
+2.0 (2 stops) 4:1
+3.0 (3 stops) 8:1
+4.0 (4 stops) 16:1
+5.0 (5 stops) 32:1
+6.0 (6 stops) 64:1
+7.0 (7 stops) 128:1
The formula for calculating the lighting ratio is:
Main light:fill light = 2:1 (exposure difference)
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