Surfing Hyperikon's website I have found a better promising bulb, in the name of the "Hyperikon 212000401" an A21 17W 120v (sic) solution, still ranging from 2700 to 5000K and advertised at CRI 92.
However, searching detailled data/tests on it, the 4000K version seems to be tested at "17" for R9 (source, indiecinemaacademy)... Meeh ? And EnergyStar tests on the supposedly same (if HyperA2190-40, A21-40, and 212000401 are the same) 4000K version R9 at 63...While the 5000K should be at R9 90 and CRI 95.
Oh, well.
EDIT : browsing indiecinemaacademy pages, have found the Quasar Science S-LED bulbs (95+CRI). Unfortunately, I can't find detailled info or other tests yet. And well, 120v again.
Hyperikon are great. I should do a review of them, I have spectrometer data. fneuf, the R9 of the 4000k are all between the low 70’s and high 60’s on all of mine. CRI Ra was in the 90’s as promised. And they are cheaper than anything else similar.
I hadn’t noticed the thread-starter was from France, but yes, many members are from NA/CA.
I’m not sure where you are going with the R9 generality, but I will post all the data.
Hyperikon’s Amazon pages are filled with pictures of lights that fried themselves, I assume from overheating. I haven’t seen anywhere close to that many proven failures from any other brand and combined with the cheap price it makes me really wary.
No, but warmer CCT’s do require a stronger red component to match their black body reference. This is difficult to achieve, especially without a hit to efficiency.
So even though a 4000K might have more red in its spectrum than a 5000K bulb, it could have a larger gap to its reference.
Same old story everywhere I believe : the fun with standards is there are many.
B22 (Swan's bayonet mount) had an original strong grip on UK (and Commonwealth) and France. But France always used both B22 (and a bit of B15) and E27 (and a bit of E14).
Now B22 mostly remain in usage in UK, India and Australia. France is "converting" (don't know of norms fixing that decision, seem to me it's a market general decision) to E27 since some years (decades), but you will still find some bayonet in old houses/rooms. The majority of Europe uses E27.
I don't have the full history of that, so it looks like a fully purposed mess. For instance I don't know why E26 and E27 both exists same time.
From their sole purpose (electric contact) they are mechanically interchangeables. So maybe it could have to deal with the 110 / 220v standard, because I think E26 is mostly in use in countries which adores 110v, whereas for E27 its 220v believers.Or could it be another cryptic example of metric vs imperial units (where 26mm would be the closest translation of some imperial measure). But this is pure speculation.
This could explain the really poor result at 17. Hyperikon's reference are not clear everywhere.
Well, well, well. Standards. Here we go again :)
Helpfully I have a map for that specific question:
Easy isn't it ? Well, we can still dig in and find more fun. More detailled map:
To each his own, standard, I guess :)
One of the great point of LEDs vs Incandescent or Halogens is that many manufacturers have cleverly took the opportunitu to build worldwide converters (90-250ish) in their bulbs. But not everyone of them.
Very interesting! I've also been recently presented an interesting article (sorry, it is in french) around the design choices of LED manufacturers to achiever High CRI in their chips
I absolutely love the negative DUV so it doesn’t look overly yellow. It is great as a nighttime light to minimize melatonin suppression. It is one of the lowest blue emitting lights I’ve measured, which is about right for the color temp but it still contains about 3x as much blue light as the E21A 2000K 9080.