-Does the High CRI show more color? Is this the main point?
The point of a higher CRI is that an LED's spectral content (i.e. the mix of various colors that make up its light) is a closer match to that of an incandescent light source of the same color temperature (i.e. basic tint). Because typical white LEDs generally have pretty smooth spectral curves and are not entirely lacking in the most significant color ranges, the main factor with respect to color rendering is still the basic tint (e.g. warm, neutral, or cool)--high CRI means that some colors may look different and more true to a similarly-tinted incandescent source, nothing more. To know what it means for each specific case and question, you have to take all of the factors into account.
So does high CRI show more color? It can sometimes when it is being compared to a source that is severely lacking in a certain range of colors, while at other times the difference will be more subtle. To take a case in point, with typical
warm LEDs, like the high-CRI LEDs used in 4Sevens' products, the difference in color rendering from that of
warm normal-CRI LEDs is usually not that pronounced--if it is, then it's probably not because of CRI per se, but other factors. Being warm-tinted means that relatively speaking there is a lot of red and orange regardless of CRI, and the area of the spectrum that is usually lacking is cyan (greenish-blue), which usually does not play a major role in how we perceive most colors in practice (at least from my own observations). A warm high-CRI LED will almost certainly have greater output in the cyan region, which may occasionally make a subtle difference in colors--maybe a little more color, or maybe not more but simply slightly different colors. However, different warm normal-CRI LEDs can render colors differently from one another as well, so the only thing you can really say about high CRI
in this specific case is that it's closer in color rendering to a warm incandescent source (which is every hot filament-based flashlight out there).
In the case of cool LEDs, however, high CRI makes a more noticeable difference because cool normal-CRI LEDs are so starved in the red area of the spectrum--they have some red but it's really deficient and very noticeable to many people. High CRI in this case means not only more cyan, as mentioned earlier, but more red while still keeping the tint cool (the additional cyan offsets the additional red). But ironically, despite the fact that high CRI makes a bigger difference with cool LEDs, the high CRI market is primarily focused on warm tints. That's probably because most people who care about color and would even be aware of CRI at all tend to prefer warm tints, which generally make colors look more vivid (accuracy being a whole other quite involved and controversial topic altogether).
By the way, it is important to note that when we're looking at different basic tints and CRI together, it's like apples and oranges because CRI is based on the tint--a neutral high-CRI LED is close to a neutral incandescent source, not a warm incandescent source, and tint generally makes a much bigger difference. So you can't say that a warm high-CRI LED is more "accurate" than a neutral normal-CRI LED on the basis of CRI, because while the former is indeed more "accurate" with respect to old light bulbs, the latter may well look more "accurate" to those who use sunlight as their ideal reference, for example, despite its lower CRI. At the end of the day, CRI is merely one factor that means one specific thing in a specific context--nothing more general or universal than that.
(So the colors should be closer as to natural daylight w/ Preon 2 Hi CRI)
Depending on how our eyes and visual systems adjust for tint, individually, it may render colors closer to natural daylight than typical cool LEDs, but not necessarily more than some neutral LEDs do, regardless of their CRI. This is because, as stated earlier, tint is generally a more significant factor than CRI alone. That said, some folks feel that cool high-CRI (really high) LEDs come the closest to natural daylight because, after all, daylight is pretty high in color temperature. Natural daylight, however, is a complex beast due to atmospheric effects, so sometimes perhaps a neutral LED (especially with a high CRI) would come the closest (e.g. direct sunlight as opposed to shade or an overcast day).
-Would I notice a real world actual difference vs my current SLSP? Are colors like grass and leaves more vivid like if I go for a walk at night?
You would notice a big difference with any non-cool LED, regardless of its CRI, so the answer is yes. Greens, browns, and reds in particular will look more vivid because they won't be overwhelmed by blue. The same would be true for any warm-tinted LED, however--I wouldn't expect high CRI to make a big difference on top of that. Neutral LEDs would also make a significant difference, emphasizing the greens more than warm LEDs; in this case, high CRI would probably make some difference in practice because it usually means more red than typical neutral LEDs.
-Is the SLSP to Preon2 High CRI a worthy upgrade, or are the lights very similar
I question whether a high CRI makes that much of a difference in comparison to other warm LEDs, but having a warm tint will certainly make a big difference in comparison to a typical cool tint. While I prefer neutral myself, I'd still take warm over cool (normal CRI) for use outdoors.
Here's a quick comparoo I just made with some lights.
From left to right:
Quark AA XP-G CW, Terralux lightstar 80, Zebralight H51w and SC51c, Preon 2 High CRI.
VERY interesting! Thanks for posting this. :thumbsup: I think that you may have just helped sell a LightStar 80 because it appears to be of a cool or cool-neutral tint (I had been under the impression that it was significantly warmer), and if it's really high-CRI then I'm intrigued. :thinking:
Note that the SC51c is also high-CRI, but of a different basic tint or color temperature (neutral) than the high-CRI Preon 2 (warm), or the LightStar 80 (cool...ish) for that matter. It has about the same overall color temperature as the H51w, but more red, as I would expect.
As being somewhat recent neutral convert myself, that warmth of preon high cri takes some getting used to.
That terralux is a nice crossover between cool and neutral, don't know if it's actually as high cri as claimed, i'd say it's similar in color as a cool white fluorescent light.
Hmmm...I have "cool white" fluorescent tubes in my kitchen, and their color temperature is around 4100K, which would usually be considered neutral in the LED world. I've compared my H51c (same LED as the SC51c--neutral high-CRI) to this light, and the LED looks pinker or peachier while the fluorescent light (Philips ALTO) is a bit greener, but they're still of similar color temperatures. The LightStar 80 in your photos definitely looks cooler than your SC51c, so maybe your "cool white" fluorescent lights are cooler than mine (or we see differently). :shrug: In any case, I think I'll have to look into this myself--oh darn!