Finding bulbs 3000K-350oK with CRI of 90-95 between 15W to 20W is very frustrating. Either hard to find, expensive from brands or dubious chinese and some solutions have to put together one. Or wrong one, like 4000K with cri of 80.
I have a strips of loose 5730 SMD LED with CRI of 95 at 3500K by Osram were so good, I can't wait for chinese made LED on PCBs to arrive and mod them with better LEDs.
Philips only sells 2700K bulbs warm white that my mom calls them yellow light, yeah, I know with a smile, and it's okay but for me needs better than that but these are usually CRI of 80 or less. And the mom's sight is not that great needs so bright light at daylight white is too stark too white, so cold and color rendering is terrible in our kitchen. Also Philips only have them available in stores that is bit under wattage than reality. Not quite similar to 100W incandescent, more like 80W because phililps has them in 14.5W and the other 60W equivalent is way less than actual.
Chinese sellers of LEDs for 5050 and 5730/5630, 2835 package are designed to source 60-150mA large die LEDs but as expected, these types you can get from chinese are fakes. 20mA LED dies in a larger packages being over-driven to 60mA at most because the die size is tiny as grain of sand. Osram I had got has real 150mA, larger rectangular LED die. Color LEDs in large dies is nearly impossible especially with chinese sellers. I have not seen any SMD LEDs with two or three LEDs in parallel especially from chinese sources either.
Safest to get in larger LED dies, easiest as well, is ones you can get is star LEDs at 3W-5W and does have bit of copper slug under them on a star PCB, but these are very old technology that was developed 20 years ago or more, was originally Lumileds's for luxeon star design, and lens attached is fake on chinese copies, it is plastic hollow dome, real luxeon stars are flat or true optical dome. And designing PCB to use them is difficult to do due to star large overall package requirements, SMD LED packages had developed further in last decade that you can get high watts LED in compact SMD LEDs and cheaper to manufacture, easier to choose any optics, can be high density by packing these more tightly.
Another is safest way to get large die LEDs from chinese sellers is 10W using real copper *plate* back in 3x3 die chips format. Yes you can under drive them too. Available in 20, 30, 50 and 100W. For white LED, the rendering is poor that limits your choices there too but fantastic choice in red, green, blue, yellow, orange and amber. Also RGB too.
Problem is you have to package it, finding optics substitutes is hard to do and making the housing to hold loose bits and sink the heat at same time.
Related to power stuff, first time bought a chinese 300W 60V 5A bench power supply. Needs one for my future electronics experiments and making circuit boards. Couldn't find one that is within my budget and voltage needed even used. Some of my LEDs is 100W and needs at least 36V for evaluating them. No, not at full brightness, I'm going to under drive them once I know how bright they can be in under driven mode.
Majority of light bulbs uses 2835 package.
Cheers,
Great Northern aka Canada.