benq 540hz vs asus 540hz scrolling, red phosphor?

[MSIfanboy]

when i bought asus many months ago, i noticed this immediately, not sure if its red phosphor backlight or ulmb2

[Discorz]

You are correct!

• PG248QP uses KSF/PFS wide gamut backlight = red artifacts during strobing
• XL2586X uses QD wide gamut backlight = no red artifacts during strobing

You can see it when eye tracking moving objects or just by moving eyes around. It's aslo easier to notice at lower refresh rates.

impulsed persistence with ksf.png (37.24 KiB) Viewed 949 times

Additionally both images show phantom array/stroboscopic effect since 540 Hz is insufficient to blur it up.