Yeah, the dip in the blue-green part of the spectrum does seem to be a limitation in all such LEDs. I suppose there has to be a gap between the stimulation and the phosphor emission wavelengths. Have to live with it!MicroBob wrote: ↑Tue May 24, 2022 7:46 pmIn my personal view a good Cree LED gives a very nice illumination for the average variety of uses. Louise posted an LED spectrum that is quite typical. White LEDs are actually blue emitters with a fluorescence layer. Apparently they can't reach "white" without the dip at 500nm at the moment with this technique. This dip at blue-green leads to a limited color vision at the opposite end of the spectrum, ca. orange. So the poor pathologist who stares at haematoxilin-eosin stained sections all day will not be happy with the common LEDs.
The CRI values don't really show this limitation so it is always worth to look at the spectrum in the datasheet.
I really like my self built LEDs conversions, they consume little energy, they last, never wore one out so far, they can be adjusted over a wide range of power (which you shouldn't do with a halogen lamp), they are easy to build for me and I have no spares problem with exotic and expensive bulbs. But of cause a good working halogen setup is good too...
Louise