GigaPan EPIC Pro User Manual page 35

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GigaPan Pro User Guide
Two methods are shown below. The first method simply requires you to count the number
of shutter values required to travel between each extreme to the average exposure. The
second method requires you to divide by two or multiply by two until you reach the other
meter reading. Let's use an example where you meter 1 second in the shadows, 1/4 sec-
ond average exposure, and 1/160 of a second in bright areas where you want to be able
resolve details.
Method One
EV distance from brightest area to average exposure using 1/3 EV shutter
settings
0 1
0 EV 1/3
1/25 1/20
8 9
8/3 +3
EV
EV Distance from shadows to average exposure using 1/3 EV shutter settings
1"s 0"8
0 setting 1
0 EV 1/3
Set your camera shutter speed to the brightest 1/160 second meter reading and then
change the shutter speed and count how many settings it takes to reach the average
1/4 second meter reading. With default camera settings you will count fourteen shutter
dial changes in order to reach 1/4 second. Divide 14 by 3 and you get 4 EV with 2/3 EV
remaining. The distance from the shadow meter reading is smaller at six shutter speed
setting changes on the dial which equals -2 EV. So the distance is 4 and 2/3 EV plus 2 EV
for a total of 6 2/3 EV distance to cover the entire range.
If you are using a Nikon {D200, D300, D300S, D700S, D3, D3s, D3x } with a nine EV span
or a Canon {1D Mark III, 1D Mark IV, 1Ds Mark III} with a span of seven EV you are able to
capture these exposures using the cameras AEB function.
You can move the center exposure which is what you set the 'Time/Exposure' setting to and
lose 2/3 stops of desired dynamic range. Another option is to use a good neutral density
filter to shift all of the exposures to shutter speeds that are slower than about 1/10 of a
second and use the BULB setting on the camera and the imager. If you use the bulb set-
ting on the camera and the imager then the imager opens and closes the shutter instead of
the camera's AEB function. Change the imager to BULB mode by changing the 'Options'-
>'Expert Options'->'Shutter Length' to 'Exposure' (bulb).
1/80 1/60
2 3 4
2/3 +1 4/3
EV
1/15 1/13 1/10
10 11 12
10/3 11/3 +4
EV
0"6
2
2/3
1/50 1/40 1/30
5 6 7
5/3 +2 7/3
EV
1/8 1/4
13 14
13/3 14/3
0"5 0"4
3 4
-1 EV 4/3
0"3 1/4
5 6
5/3 -2 EV