Sekonic LITEMASTER PRO L-478 Series - 6-4. Contrast Function

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6-4. Contrast Function
Thisfunctionisusefulforevaluatingstudiolighting,checkingevennessofbackgrounds
suchasgreenscreens,andquicksetupoflightingratios.
Afterestablishingastandardvalue,pressandholdtheMeasuringbutton
8
todisplaythe
differencebetweenthestandardandnewmeasuredvalue.Theexposurevaluewillchange
toanEVvalue(differenceinstops)changeasbrightnessofthemeasuredvaluechanges.
TheAnalogScalewilldisplaythecurrentmeasuredvalue.
*Ifnovaluesareinmemory,thestandardvaluewillbethelastvaluemeasured.Ifvalues
areinmemory,thestandardvaluewillbetheaverageofallmemorizedvalues.
Creating Lighting ratios with Contrast Function (in Shutter Speed Priority Mode in incident light):
RetracttheLumispherewhenmakingcontrastreadings.
1. RotatetheLumisphereretractingring
2
until
fullyswitchingtotheatposition.
2. SwitchONthemainlightsourceandpointthe
retractedlumisphereatthelightsourcefrom
thesubjectposition.
3. TouchtheAverage/
D
EVicon at the
bottomofthescreentousethecurrentreading
(ormemorizedvalue)as“StandardValue"and
displayAVEonthemeasuringscreen.The
Average/
D
EVicon will appear in reverse
aslongasitistheContrastFunctionisactive.
4. NextturnONasecondlightsource(lllight,
hairlight,etc.).Pointtheretractedlumisphere
atthesourcefromthesubjectpositionand
presstheMeasuringbutton
8
.Thedisplaywill
changefromexposuresettingtoEVvalueand
indicatethedifferenceinbrightnessbetween
theStandardandthesecondvaluebeing
measured.Theanalogscalewillalsodisplaythe
twovalues.Thetablebelowshowsthelighting
ratioaccordingtothedifferenceinbrightness.
EVDifferenceofMeasuringValue IlluminationRatio
1 2:1
1.5 3:1
2 4:1
3 8:1
4 16:1
5. Toreturntonormalmeasuring,touchtheAverage/
D
EVicon again.
•
To determine the nal exposure after setting the lighting ratio, extend the lumisphere, switch ON all lights, and point
the Lumisphere back towards the camera from the subject position and press the measuring button.
•
The Contrast Function also can be used when measuring with reected light.
Lumisphereretractingring
2
Ave
Setting
value
TouchAVE/
DEVicon
Release the
Measuringbutton
ExampleofMainLight
Source Measuring
Measuring value
usingmainlightsource
LastmeasuringValue
Standard
Value
Exampleofwhilecontrast
function is active
Standard value
(mainlightsource)
Monitored value
(second light
source)duringmeasuring