Ok, I admit this is all about how we perceive light. Our eyes aren't bionic implants so our brains compensate. But, I wonder if anyone has either thought about or figured out a better way to do this.
Let's say you are fading an LED from 0 up to 255 then back down to 0 in +1/-1 increments (let's call it a 'pulse'). Well, from 0 to about 175~200, you'll notice it. But going above that, the change is so minute that it's barely noticeable. Yes you can notice it, but it's not as dramatic a change as going from say 100 to 150.
So I thought maybe when one reaches those higher numbers, instead of continuing with a +1 step, change to a +2 step, so the fade reaches max intensity faster. Then I thought, there's got to be a better way. Maybe a formula? Or maybe I'm just going about it all wrong. I may even be over thinking it, who knows. I just know that when I'm fading an LED up to max then down to 0 again, it just seems to stay near it's max intensity longer than any other range. I know it's not, but the light intensity makes it appear that way.
So is there a better way for a smoother "pulsing" of an LED?
A logarithmic or exponential formula would probably provide a visibly smooth enough fade on/off. It may not be a perfectly accurate method, but likely close enough that the human eye won't perceive any inconsistencies.
KirAsh4:
I just know that when I'm fading an LED up to max then down to 0 again, it just seems to stay near it's max intensity longer than any other range. I know it's not, but the light intensity makes it appear that way.
No, it probably is. Light output from a LED isn't linear.
KirAsh4:
So is there a better way for a smoother "pulsing" of an LED?
KirAsh4:
I just know that when I'm fading an LED up to max then down to 0 again, it just seems to stay near it's max intensity longer than any other range. I know it's not, but the light intensity makes it appear that way.
No, it probably is. Light output from a LED isn't linear.
I think we're talking about PWM driving an LED, so the average light output is theoretically linear in the PWM duty-cycle. Self-heating reduces efficiency somewhat so linearity is best at lower output powers. The human eye has nochance of detecting this degree of non-linearity since the response curve is roughly logarithmic over many orders of magnitude (5 or so)