Talk:Stevens' power law

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I figured out that α is the exponent in the given table, but what value is k supposed to be? the article doesn't mention k anywhere. --Abdull 11:55, 23 Mar 2005 (UTC)

k depends on the particular type of stimulus and the units used. It doesn't make much sense to specify k since there are no clear units for "subjective sensation" anyway. AxelBoldt 23:35, 10 September 2006 (UTC)

[edit] Law's predictions

Naive that I am, I would claim right away that

ψ(I) = kI^a

is obviously false, at least in cases where a < 1. The law predicts in these cases that, if I is close to zero, tiny increases in I result in tremendous increases in ψ (the first derivative of ψ at 0 is infinite). But we all know that when I is close to 0, ψ is equal to zero. AxelBoldt 23:35, 10 September 2006 (UTC)

[edit] In English please

Okay, if I have a point source of light physically 100 times brighter than another, how many times brighter will it subjectively look?

What about 2 times, 10 times etc?

I get a feeling the exponent 'a' is like "gamma correction" for a logarithmic scale, am I right?

Please explain the law better. I still don't know how to convert physical and subjective. Sagittarian Milky Way 20:54, 21 April 2007 (UTC)