First clip: CFL only in Ikea light fixture
Second clip: overhead lighting at full (uses standard phase dimmer) along with the floor CFL lamp later.
Third clip: Incandescents in Ikea fixture. (Sorry for lack of focus)
A few months ago I got a Ikea floor lamp with what appeared to be CFL lights preinstalled. I didn't think much of it at the time but I was able to see some stroboscopic effects right away. I thought i was crazy because of the lighting industry's claim "CFL's don't flicker hurr durr" but of course I knew that was BS because I went to a friend's house with CFL's and had symptoms right away and the CFL's were later identified as the case using my DSLR.
(they were very cheap one's. I've seen CFL's that don't flicker with my own eyes but they are pricey. Remember the post I made mentioning the hotel I went to)
I was worried the CFL's in my floor lamp were contributing to my headaches so I made a video of them vs installing standard incandescents in the fixture. Keep in mind AC power in North America runs at 60 HZ (50 in Europe, idk about others). So all lights running on AC here run at either 60 or 120 HZ. Incandescents just have a very short form of "duty cycle/off period" based on the heating if you will, hence why nobody has problems with them vs fluorescents or other forms of lighting.