>Psychtoolbox>PsychColorimetric

[trolands] = EffectiveTrolandsFromLum(lum,[method])

Compute effective trolands for large fields from photopic
luminance. Based on LeGrand’s work, takes Stiles-Crawford
effect into account.

Luminance is in cd/m2.

Method (string):
PokornySmith1: (default)
Formula is Eq. 2 from: Pokorny and Smith, “How much light
reaches the retina”, Colour Vision Deficiences XIII (C.
Cavonius, ed.), pp. 491-511. The formula in the paper
has some typos, corrections provided to me by Pokorny.

    [PokornySmith2](PokornySmith2):  
        Formula is Eq. 3 from: Pokorny and Smith, "How much light  
        reaches the retina", Colour Vision Deficiences XIII (C.  
        Cavonius, ed.), pp. 491-511.  Conversion to and from log  
 done here so input/output is same as above.  

The agreement between the two methods is not spectacular. See PupilDiameterTest.

5/8/99 dhb Wrote it.
7/11/03 dhb More general method naming.