Bests & Worsts Reviews from Amazon

I purchased these lights specifically to replace equivalent lights in my home that have a 60Hz flicker. The flicker has annoyed me for some time now to the point where I no longer use the lights at all. I purchased these bulbs based on other reviews that said that these lights do not flicker, but I have found by recording them in slow motion that they do in fact flicker. Allow me to explain a bit further what this flicker is, what it's caused by, and why it bothers me but goes unnoticed by many people: An LED is a "light emitting diode" which means exactly what it sounds like; these devices are diodes that emit light. A diode allows current to flow in only one “direction”. The power in most households in North America and around the world is alternating current. Alternating current (AC), like the name suggests, alternates between positive and negative current flow (It flows in two “directions”). Instead of having a positive and negative wire like direct current (DC) devices (think of a battery with a positive and negative terminal, batteries provide DC current), alternating current uses a "hot", or "live" wire, a neutral wire, and a ground (In DC applications the negative wire is usually also the ground). So essentially, the “direction” of current flow is alternating in AC applications. Now you know 2 things. The power in your home is alternating current, and LEDs allow current to flow in only one direction. Alternating current in North America has 60 phases per second, or operates at 60Hz frequency. Each "phase" lasts 1/60th of a second and consists of positive and negative half-phases, each lasting 1/120th of a second. Now look at the annotated diagram of an alternating current sine wave I uploaded. 1/2 of the time the voltage function is above zero (positive), and 1/2 of the time the function is below zero (negative). The individual LEDs on the circuit board of a light bulb can be oriented so that they are either on during the positive half phase, or on during the negative half phase, but each individual LED cannot be on during both phases in a simple LED circuit. Therefore, this LED light flickers at a rate of 60Hz. Now you may be thinking at me, "well, if you knew this, and the flicker bothers you, why would you ever buy a LED bulb?" which brings me to the next thing I would like to explain. Not all LED bulbs flicker!!!!! LED bulb manufacturers can include AC to DC converters in their LED bulbs to get rid of the 60Hz flicker. These circuits take the 60Hz 120V AC power supplied by your home's power and turn it into a DC power source. This is a function your phone charger provides for your phone. It provides your phone with 5V DC power to charge its internal battery. AC to DC converters are very common in LED bulbs, but one is not built into this bulb, which is why this bulb flickers. In summary, LED’s which are powered by a DC power source do not flicker. If a LED bulb has an integrated AC to DC converter, it will not flicker (it also may take a second to turn on and may fade off when turned off). So, why might you not notice this flicker when I do? I don't know the exact answer to this because it does have a bit to do with psychology, and I’m no expert on that (I’m not an expert on anything, not even LED bulbs). With that said, I think it is due to a few factors. I think many people do, at first exposure, notice that the light from some LED bulbs is different than light from incandescent or fluorescent bulbs, but they might not care, they might dismiss it, or they might think their eyes are playing tricks on them. They accept that it seemed a little bit different, subconsciously think to themselves “These are normal lights, look at everyone else acting normal, they don’t notice anything so neither should I,” and move on. I notice this because I am aware of it. When I was young, I had an interest in electronics, and I first noticed 60Hz flicker in old cathode ray tube (CRT) computer monitors and TVs. If you put your hand in front of an old CRT TV and move it around rapidly, instead of seeing your hand move in a blur, you will see sort of snapshots of your hand in different positions as you move it. This can also be noticed under the light of an LED that flickers, but it is a bit subtler in that situation. If you have never paid any attention to the flicker of any screen or any light bulb, you are not likely to notice it. Also, some people I have tried to demonstrate this to have trouble seeing it even when it is pointed out to them. If you were to put these lights above your kitchen sink and wash dishes every night, I would be surprised if you don't notice the flicker at some point in the first few months of use. With this said, let me describe how I observe a light flickering. I'm not super human, I can't stare at a light and tell you if it flickers. The minimum frequency for a human eye to detect flicker is 18Hz. However, that is for looking directly at a light source that is flickering. When motion is involved, things get a little bit different. Remember the screen example I mentioned earlier with old CRT TV's or monitors? I cannot stare at a CRT monitor or TV and tell you whether it is flickering, but if I put my hand out in front of it and move my hand around, then I can tell you if it’s flickering. There are two ways I would recommend trying to observe whether lights flicker in the room you are in. One is to look at something on one side of a room, then quickly move your glance to the other side of the room and pay attention to your peripheral vision. If the light is flickering you will have seen the light in a few different spots in your vision, and if the light is not flickering you will have seen a streak of light as your eyes moved. Another way to tell is to move your hand, or a shiny object quickly under the light source without following it with your eyes. For example, I noticed that my current lights flicker while setting up my speakers for my TV. I had shiny gold-plated RCA cables in my hand, and when I moved my hand and the ends of the cables swung around, I noticed that instead of seeing a streak from the cable ends, I was seeing the ends in different spots in my vision. A definitive way to observe flickering lights is to use the slow motion effect on your smartphone. Check out the video above where I have recorded the light in 960fps with my phone. When the slow motion footage is playing back you can easily see that the light flickers. This will also work with 240fps. Here is a direct quote from this item’s description at the time of my purchase: "50,000 hours rated lifetime. Instant on, no flicker, no UV, mercury free light. 15W, 950L, 120V." Notice specifically "no flicker". I have noticed that most LED bulbs that have "Instant on" also flicker. One more thing that I would like to point out about these LED bulbs is that they are 15W bulbs that emit 950 lumens (for the 2700k model). This is a relatively low efficiency of 63.33 lumens per watt. I am pointing this out because for a bulb that flickers, this is a low efficiency. Including a AC to DC conversion circuit in a LED bulb typically reduces efficiency, and these bulbs do not have AC to DC conversion circuits inside. As a reference, a Phillips brand LED I purchased in 2016, which has the exact same color temperature of 2700k and an AC to DC conversion circuit, emits 800 lumens using 9.5W, which is an efficiency of 84.21 lumens per watt.