Quote from: Gareth on February 12, 2013, 07:51:59 PMOK, the tint thing might not be totally Heinz's fault. I also found myself with an old incan torch that was given to my daughter and thinking "that really is a nice colour of light". Everything else was exactly what you'd expect, dull, ringy etc, but it was nice and "warm" to look at. Another convert! The thing about warm tints is they tent to be strongest in the range of the spectrum our eyes are most sensitive to. The long wavelength (red) cones, and the medium wavelength (green) cones have a fair bit of overlap in the range of wavelengths they're sensitive to. The brain encodes brightness based on signal intensity, and as a result, when viewing two objectively equally intense narrow spectrum lights (measured in photons, candelas, whatever), one yellow and one blue, we will see the yellow one as brighter. That's simply because there are a lot more cones in the eye being stimulated and therefore producing a stronger signal sent to the brain. Now it's true that a cool tint emitter will be objectively (and perceptually) brighter than a neutral or a warm tint emitter, but this is because of how tints are done on LEDs. They're coated with a phosphor layer that absorbs some portions of the spectrum, particularly the higher temperature wavelengths. So even though we're more sensitive to warmer temperatures, we still see a cool tint as brighter because it has a greater amount of total wavelengths in its power spectrum than a neutral or warm tint emitter produces.The advantage of this, though, is that because of the medium and long cones are being stimulated more by a neutral or warm tint, it provides a stronger activation in what's called the parvocellular retinal ganglion system. There are actually five major kinds of different neurons in the retina, with rods and cones being only one type, the photoreceptors. There are at least four different kinds of retinal ganglion cells, and there may be a new one that was just discovered in the last few years, but I'll have to check to be sure... Anyway, ganglion cells are the ones that get signals from the photoreceptors and then send that information to the brain. There are several sub-types, with the magnocellular and parvocellular being the two main types. It's the parvocellular ones that give us our detail, acuity, and color vision; the magno cells only encode motion and changes in brightness. Anyway, to get back to the point, the extra activation of the parvocellular system gives us better depth perception with a neutral or warm tint. Shadows appear crisper and darker as a result, and it's those brightness differences that also affect the magno system, which increases our sense of depth with a neutral or warm tint as well. The magno system does get input from the cones, but it's important to note that rods only send their input to magno cells. Thus, when you're fully dark adapted, what's called scotopic vision, only your rods are working as those levels of light are too dim to actually activate the cones. Rods are six to ten times more sensitive to light than cones are; it takes only a single photon of light to stimulate a rod to fire an action potential. A cone on the other hand, requires (you guessed it) six to ten photons of light to activate and produce an action potential. What's more, rods are maximally sensitive at a wavelength of about 505 nm, which is on the green/blue borderline of the visible spectrum, but yet that information isn't encoded by the brain, so we are literally color blind when in true scotopic vision. This results in a simple rule of thumb to know if you're truly in scotopic vision; if you can see the color of the light, it's too bright, and you're compromising your scotopic vision. I guess I should just skip explaining the difference between dark adaptation and scotopic vision for now, since I've really gone off on a wild tangent here! Okay, brain-dump over.
OK, the tint thing might not be totally Heinz's fault. I also found myself with an old incan torch that was given to my daughter and thinking "that really is a nice colour of light". Everything else was exactly what you'd expect, dull, ringy etc, but it was nice and "warm" to look at.
Quote from: Heinz Doofenshmirtz on February 12, 2013, 08:36:25 PMQuote from: Gareth on February 12, 2013, 07:51:59 PMOK, the tint thing might not be totally Heinz's fault. I also found myself with an old incan torch that was given to my daughter and thinking "that really is a nice colour of light". Everything else was exactly what you'd expect, dull, ringy etc, but it was nice and "warm" to look at. Another convert! The thing about warm tints is they tent to be strongest in the range of the spectrum our eyes are most sensitive to. The long wavelength (red) cones, and the medium wavelength (green) cones have a fair bit of overlap in the range of wavelengths they're sensitive to. The brain encodes brightness based on signal intensity, and as a result, when viewing two objectively equally intense narrow spectrum lights (measured in photons, candelas, whatever), one yellow and one blue, we will see the yellow one as brighter. That's simply because there are a lot more cones in the eye being stimulated and therefore producing a stronger signal sent to the brain. Now it's true that a cool tint emitter will be objectively (and perceptually) brighter than a neutral or a warm tint emitter, but this is because of how tints are done on LEDs. They're coated with a phosphor layer that absorbs some portions of the spectrum, particularly the higher temperature wavelengths. So even though we're more sensitive to warmer temperatures, we still see a cool tint as brighter because it has a greater amount of total wavelengths in its power spectrum than a neutral or warm tint emitter produces.The advantage of this, though, is that because of the medium and long cones are being stimulated more by a neutral or warm tint, it provides a stronger activation in what's called the parvocellular retinal ganglion system. There are actually five major kinds of different neurons in the retina, with rods and cones being only one type, the photoreceptors. There are at least four different kinds of retinal ganglion cells, and there may be a new one that was just discovered in the last few years, but I'll have to check to be sure... Anyway, ganglion cells are the ones that get signals from the photoreceptors and then send that information to the brain. There are several sub-types, with the magnocellular and parvocellular being the two main types. It's the parvocellular ones that give us our detail, acuity, and color vision; the magno cells only encode motion and changes in brightness. Anyway, to get back to the point, the extra activation of the parvocellular system gives us better depth perception with a neutral or warm tint. Shadows appear crisper and darker as a result, and it's those brightness differences that also affect the magno system, which increases our sense of depth with a neutral or warm tint as well. The magno system does get input from the cones, but it's important to note that rods only send their input to magno cells. Thus, when you're fully dark adapted, what's called scotopic vision, only your rods are working as those levels of light are too dim to actually activate the cones. Rods are six to ten times more sensitive to light than cones are; it takes only a single photon of light to stimulate a rod to fire an action potential. A cone on the other hand, requires (you guessed it) six to ten photons of light to activate and produce an action potential. What's more, rods are maximally sensitive at a wavelength of about 505 nm, which is on the green/blue borderline of the visible spectrum, but yet that information isn't encoded by the brain, so we are literally color blind when in true scotopic vision. This results in a simple rule of thumb to know if you're truly in scotopic vision; if you can see the color of the light, it's too bright, and you're compromising your scotopic vision. I guess I should just skip explaining the difference between dark adaptation and scotopic vision for now, since I've really gone off on a wild tangent here! Okay, brain-dump over. Ahhhhhhhhhhmy brain hurts.great post HeinzStay Warm
Just arrived today and I've had a couple of minutes to play with it. Initial impressions are very good.
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