I believe I have found a method to test computer monitors, TVs, phones, laptops, etc. for headache-inducing flicker using a powerful photodetector (Thorlabs PDA100A2) and oscilloscope. It can zoom 3000x, which I believe is way beyond what anyone on this forum has used. Hats off to @KM who had mentioned it in a previous post and also described how to build a DIY device that I’ve been using.
Like many on this forum, I have a handful of devices that work for me and a growing junkyard of devices that I thought would be usable but in fact give me headaches. So I set about looking at each of my screens using the Thorlabs photodetector to see if I could tell the difference between the screens that give me headaches and the screens that do not.
When I zoomed to 100x magnification, I was able to see significant differences in the amount of flicker between screens that bother me and screens that do not. I then went to Best Buy and spent about 3 hours wandering the store testing 100+ devices (phones, TVs, laptops, etc.) in search of truly flicker-free devices. I was able to find about five laptops/chromebooks, one iPad, zero TVs, zero phones, and zero computer monitors.
Let me try to boil it all down to three screen shots:
My trusty Dell 5567 laptop that I’ve been using for five years without symptoms. There is barely any flicker.
A used Dell 5567 that I bought a few weeks ago as a backup. I cloned the SSD drive, so everything should be the same. But this one gives me headaches within minutes. The flicker is clearly visible.
An example flicker-free device that I found at Best Buy, just to prove that such a thing exists. This happens to be a laptop that I went ahead and ordered but have not yet received.
I really want to get some more people involved in this as I think this testing could have a huge impact. I have two ideas, but I’m sure there are others I’m not thinking of.
Idea #1: If someone with a variety of good and bad devices is willing to repeat my experiment, I’m happy to loan you my equipment. It’s not terribly difficult, but there are some steps that must be followed precisely. If you’re good at things like setting up your home theater system, you’ll probably be able to do this without any problems.
Idea #2: I could visit some other stores and find a truly flicker-free monitor, buy a dozen of them, test them for flicker (just because the display model doesn’t flicker doesn’t mean the ones I actually get won’t flicker), return the ones that flicker and re-sell the flicker-free ones to people on this forum for cost + shipping. Then the people who buy these monitors could then confirm whether they are usable for them or not. We could conduct the purchase through eBay so you’d be protected if something went wrong (I have a 100% positive rating on eBay). I plan to do this for myself anyway because I’ve been wanting a new monitor (I have a decade-old 22” monitor that’s been good for me but it’s not working as well as it once was and I’d like something a little larger).
I’ve got tons of more details, ideas, theories, etc., but don’t want to overwhelm you with information.
In short, is there anyone who is willing to help validate my findings?
Here’s those three screen shots.