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GregAtkinson

GregAtkinson I tried the Maxlite 2700K 60W bulbs a couple weeks ago, but as @GregAtkinson and I expected they might given the spiky shape of the flicker waveform, they made me sick with concussion-like symptoms, although were definitely better than LEDs with high flicker. They were similar to other low-flicker lights that still injure me (data here). These were the MaxLite 2700K A19, E9A19D27/49/WS1, Code 14099718. So maybe they have the new, worse engineering? These had 0.17% flicker (calculated in the standard, misleading way used by the lighting industry).

0.5 seconds (UPRTek flicker meter) with the x-axis at y=0:

0.05 seconds and zoomed-in y-axis:

I received the LG 27MQ450-B from @GregAtkinson last weekend, and I set it up as my main monitor at work to give it a thorough test. Around the same time I also received the Opple Light Master 4 I had ordered, which I know has limited capabilities, but I thought it would at least provide an empirical measurement along with my subjective perceptions.

Leaving the display settings as they came (Brightness=100, Contrast=40), my very first impression was that the picture appeared somewhat unstable. I had a slight perception of the picture moving or flickering. I took a few readings of a white background with the Light Master, and all readings were something like this (I calculate 12.6% flicker using (max-min)/max):

I ultimately reset the brightness and contrast settings to their defaults (I believe ~75 for both), and the picture looked brighter and more stable, although still not as stable as my old Dell monitor from 2013. I initially thought this might be usable once I got accustomed to it. I took another Light Master reading of a white background, and got this (I calculate 7% flicker using (max-min)/max):

I then tried reading emails on the screen for an hour or so (my typical use pattern). Unfortunately, I got the symptoms I get with most modern displays: focus problems, blinking constantly, a feeling like a flashlight is shining in my eyes, lack of comprehension, etc. I forced myself to use it for a few days, and perhaps adapted to it slightly but not significantly.

I am open to thoughts on this, because this sounds contradictory to GregAtkinson's testing indicating very low flicker. My initial thought was that the AC power in my office may not be very clean, or that there could have been a GPU output issue (however, none of these changed from my old setup, which was perfectly comfortable). I was connected via DisplayPort, just like previously (well, previously it was a DisplayPort to DVI adapter), so I wonder if I should try a different cable or try connecting via HDMI. I also am a novice user of the Light Master device, but the measurements do seem to correspond to my real-world discomfort.

For reference, this was a Light Master reading of my old Dell monitor from 2013, which I found perfectly comfortable (the PWM is quite evident, but I can use this all day long):

Got it. Funny enough, it looks like @GregAtkinson posted a review for this product.

Hi @GregAtkinson -- wondering how you are doing nowadays? Is the Paxil still helping?

I bought 4 different brands of LED bulbs off of Amazon and tried them out. Currently, I only have slo-mo phone camera for testing, but am working on an oscilloscope solution to get better results. With slo-mo camera, I can detect flickering (from AC current) in my incandescent and halogen lighting for control. I notice that some LED bulbs flicker similarly to incandescents and some flicker much more sharply. Below are my findings on four brands.

Energetic PAR38 3000K- I detected no flicker with slo-mo video. It's not a perfect test and I wish I had an oscilloscope, but it's the best I can do at the moment. I figure if I can detect incandescent flicker and nothing on these, then it's reasonable to deduce that they don't flicker at all. I only tried their PAR 38 bulb but would hope that their other bulbs would have similar technology. They also make an A19 bulb. My only beef with Energetic is their warmest bulb I can find is 3000k. I prefer warmer light indoors. However, I do like this cooler/whiter light for outside and I'm going to put these bulbs around the exterior of my house.

Sunperian BR40 2700K - On this one I could detect flicker, but it was very similar, if not the same, to the flicker of incandescents. Interestingly, when you turn this bulb off, it "glows down" like an incandescent. You can see it slowly get dimmer and dimmer before turning off. It "glows down" more slowly than the incandescent bulbs that were right next to it. So, my thinking is that they have introduced some technology in LED bulbs to have them show some afterglow just like incandescents when the power to them is cut. If this afterglow also takes effect with the oscillating AC current, then I would expect an oscilloscope wave for these bulbs to look similar to an incandescent's wave and MAYBE be ok on our eyes and heads. I didn't love the color of this bulb either, they call it a 2700K but it felt more like 3000+K to my eyes, that's all very dubjective though.

Torchstar BR30 3000K - This one behaved very similarly to the Sunperian above as far as flicker. It MAY have been a slightly sharper flicker than Sunperian's but that's really hard to know for sure just using video. Even though this bulb is a 3000K, it felt slightly warmer than Sunperian's 2700K. I would like to try a 2700K version of this bulb for a bit of time to see how they feel with long-term use.

Sunco BR30 2700K - The Sunco bulb displayed a very noticeable, very sharp flicker. It is noticably distinct from the flicker of incandescents and the other 2 LEDs. I suspect that it would show the blocky waveform of the instant on/off oscillation that many LEDs do. This one also seemed to strain my eyes right away and I imagine would give headaches with any prolonged usage.

Summary:

Energetic - Seems good and usable

Sunperian - worth trying

Torchstar - worth trying

Sunco - Stay away

I'm also going to try Greg's recommendation above. Thanks @GregAtkinson for that info!

Next step is to find/build an oscilloscope of my own and test more bulbs.