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Index › Programming Questions & Help › Syntax Questions › gamma correction for fade values of an led
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gamma correction for fade values of an led? (Read 634 times)
intellijel
gamma correction for fade values of an led?
Jul 22nd, 2009, 3:23pm  
I am using processing via arduino to control an led. The led has a 10bit register for pwm values (i.e. linear control of pwm amount).

Linear changes in pwm value do not correlate to linear changes in perceived change in brightness. (I think this is an issue of luminance vs. brightness)

What is the best function to use instead?

For now I am simply approximating using y=X^2.5/1023

where 2.5 is my gamma correction exponent
and 1023 is the max. pwm register value

From what I can tell so far this is called Gamma correction and there are some equations I have come across but do not totally understand.
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« Last Edit: Jul 22nd, 2009, 4:39pm by intellijel »  
 
PhiLho 
Re: gamma correction for fade values of an led?
Reply #1 - Jul 23rd, 2009, 1:21am  
It is more a question for the Electronics section of the forum than a syntax question... (which obviously means "any question" to most people anyway).
I haven't made electronics in ages... Does all the LEDs have the same response curve? If not, you should look at the specifications of your kind.
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