In this quick review, I tested 10 different LED bulbs using a spectrophotometer. Impressions and detailed information - under the cut.

Used a USB-650 Red Tide spectrophotometer as a test tool: ($ 1840 + shipping).
There will be a minimum of photos, mainly graphics, and features.
We will look at two main parameters (I will give a very simplified, "kitchen" description):
Correlated Color Temperature (CCT). Roughly speaking, the higher this value, the more cyanotic the color, the lower - the more it tends towards orange. The optimal value is considered to be from 4500K to 6500K. The specific meaning is a subject of controversy and discussion, science has not yet come to a specific solution.
Color rendering index, CRI or Ra is a parameter that characterizes the level of correspondence of the natural body color to the visible (apparent) color of this body when it is illuminated by this light source. The higher the better, but the visibility also decreases. Let's say the difference between 60 and 70 is significantly more noticeable than between 70 and 80.
If you are interested in a more detailed description of these parameters, then the wiki has articles on the topic:


And I will move on to the review.
I'll start with the light bulb in the title. There are many options, I took a non-dimmable 85-265V, 8W model. I took such a model because I wanted with a normal driver, so that it would not flicker. Unfortunately, it flickers and is quite noticeable.




The color rendering index of -86 is very, very good, but the color temperature of 2577K is approximately like a 220 volt incandescent light bulb, if you turn it on at 160 volts. Visually, it looks more like sodium lamps of outdoor lighting. Hike, noticeably flickers with a doubled network frequency, Therefore, I will not recommend it.
No. 2 - Corn for 263 pieces of 5mm diodes with DD4:
(Link is dead, don't go in vain)




What can I say? - p-ts, not a light bulb. Sinit is terrible, as can be seen from the color temperature - as much as 22663K, well, the color rendering index - 71.7, is also not a fountain. Probably it is possible not to write about something that flickers like hell, and it is clear that a light bulb is rubbish.
# 3 - Little Corn from Gearbest:





Also bluish - 8209K, and the color rendering index is also not so hot - 70.4. Of the advantages, I note the presence of a normal driver and the absence of flicker, so it is quite possible to enter the hallway, to the staircase, and so on.
# 4 - Small bulb with DD4:





Also a little blue, but quite tolerable. There is a noticeable flicker as the capacitor ballast is used. For non-residential premises - it is quite possible. CRI = 68.4, CCT = 7648K
# 5 - Magic Blue Light Bulb from Gearbest:





The color temperature here is 3207K, the color rendering index is quite high - 82.7, and there is no flicker at the mains frequency, or doubled mains frequency, but there are two noticeable drawbacks: 1 - Low power, approximately corresponds to a 25W incandescent lamp, and the brightness is regulated by PWM, so flicker will be noticeable at low brightness.
# 6 - Mini Corn with Cndirect:
(The site is buggy terribly)



The color temperature is 3163K (tolerable), but the color rendering index is 59.2, so the color looks more like a car fog than an incandescent lamp. In addition, the circuit with a ballast capacitor, and the filter was not installed at all, so it flickers terribly. I do not recommend buying in any way.
No. 7 - Light bulb with imitation of filaments with Buyincoins:





In terms of the quality of the measured parameters, the color rendering index is 85.8, the color temperature is 6575K, this is a champion of this review, and its light is very pleasant, but as always, we regretted the capacitor in the filter, so we have a terrible flicker with twice the frequency of the network. So it can only be recommended if you modify the nutrition.
# 8 - 5W ice bulb purchased offline for $ 3, cold white:



CRI = 75, CCT = 8630K, which in human language means a slightly noticeable blue, and so-so color rendering. One of the advantages is the absence of flickering, because there is a pulse driver.
The next two positions, these are already bulbs of a different principle of operation, gave the results for comparison.
No. 9: General Electric Energy Saving 6500K:




On the face is a very interesting spectrum, which is fundamentally different from the spectrum of LEDs - we have several pronounced peaks. Total, 8234K and 76.2 - indicators at the level of an average ice bulb, nothing special. I especially did not like the peak at 365nm - this is already ultraviolet, which is very undesirable for the eyes, and its intensity is high. On the plus side, there is no flicker and good workmanship.
No. 10 - 77W halogen bulb OSRAM:





Monotonous, beautiful line, monotonously growing towards IR. CCT = 2809K, CRI = 97.7 Flicker is not noticeable. In general, class, if not for the terrible heating.
Total. In this review, I examined 8 LED bulbs purchased from popular online stores. As can be understood from the text and graphs, it is impossible to take and replace an ordinary incandescent lamp with them like this - either the flicker is strong, then the color temperature is low, then the color reproduction is poor. You might get the impression that LEDs are bad. As if not so, I would say differently - Inexpensive LED bulbs are bad. And for comparison, I will give a spectrum with an expensive LED light bulb, which costs not $ 2-5, but $ 30:



+ You need a native driver (Chinese ones do not fit), which costs about $ 20, and a radiator (well, let's say $ 10). And what do we get by spending "only" $ 60 on one light bulb?


3517K and CRI = 89.5 - Very, very decent. Naturally, there is no flicker. Visually, the light is like a good, sunny day, at 3-4 o'clock in the afternoon, in the middle lane. Will you say expensive? I agree, it's expensive, but for me personally, my own health and the health of my children are more precious.