Just FYI for those who are interested, the rate at which a light has to pulse in order to be seen as continuous is referred to in the study of visual perception as the CFF for 'critical flicker frequency' or 'critical fusion frequency'.
As a light gets brighter, the CFF rate must increase in order for it to be perceived as continuous because the increase in brightness results in an increase in contrast between the on and off of the flickers.
In and of itself, the visual system has a lower and upper bound for how often an image has to be presented in order to appear to be moving smoothly. In terms of animation this translates to a frame rate of about 24 fps. Anything slower than that and motion appears to be discontinuous, getting more and more jerky and the frame rate decreases. This translates to a lower bound of about 45 ms per frame or stimulus presentation.
As an example of this is a psychophysical phenomenon called apparent motion. Take two dots of light that are presented on a computer screen a small distance apart, say 3 or 4 cm.
-Present the first dot for 50 ms, extinguish it, then another 50 ms later, present the second dot for 50 ms. The observer will perceive two separate dots appear and disappear at the same time.
-Present the first dot for 50 ms, extinguish it, then another 75 ms later present the second dot. The observer will see the first dot start to move in the direction of the second but disappear briefly and reappear slightly before the actual position of the second dot and move to the actual position of the second dot before disappearing. This is called phi-motion.
-Present the first dot for 50 ms, extinguish it, then another 100 ms later present the second dot. The observer will see one dot that appears on the screen move across the screen to the actual location of the second dot without interruption and for the entire distance between the two dots, then disappear. In other words, it looks as if a single dot appears, moves contiguously across the screen to the second position, then disappears. This is call beta-motion. The dot is perceived to move across the intervening space between the two locations even though no such stimulus is ever actually physically presented.
-Present the first dot for 50 ms, extinguish it, then another 150 ms later present the second dot. The observer will see one dot appear then disappear, then the second dot appear and disappear. No illusory motion is perceived.
Now of course, as the brightness and other characteristics vary (as well as individual differences between observers) these time intervals will vary slightly, but they are remarkably consistent in terms of the range of values that are found through scientific observation of this phenomenon over literally 150 years worth of work on this perceptual phenomenon.
So if the pulse rate of the Preon is 2.4 KHz, that means each pulse is occurring about every .4 ms so even at the Preon's maximum output of 160 lumens, the flicker frequency is high enough for the light to be perceived as continuous in pretty much every situation it might be used/seen/observed in.
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Reverse clickies just SUCK! I'm counting on the LD05 being a forward clicky, not just for myself, but also for Christmas gifting to someone who prefers forward as well.
