Frequently Asked Questions
Q: Why Do Some LCDs Have Image Retention With BFI?
The mechanism is explained in an existing thread I wrote a long ago at
Why do some LCDs have image retention with BFI?
In short, BFI sometimes synchronizes to the alternating voltage of the LCD voltage-inversion algorithm, so static electricity builds up in opposite voltage polarities on the visible frames versus black frames, creating an image retention.
Q: How do I fix my image retention?
Play some content for a loop for a while. If it doesn't fade away after an hour, then keep the monitor turned off for a while before turning it back on. Then play some video for a few hours. Keep cycling until the image retention fades away.
Q: Are Other LCDs Affected?
Yes. I have seen image retention on TN, IPS and VA LCDs. Some are mostly immune while others have some side effects. It varies from brand to brand, LCD to LCD.
Q: How do I use BFI or CRT safely with LCDs?
There are two methods:
1.
Use odd divisible refresh rates, like 60fps BFI at 180Hz (3x) or 60fps BFI at 200Hz (5x). These odd divisors are
IMMUNE to image retention. Don't use 2x refresh rate. Don't use 4x refresh rate. Don't use 60fps BFI at 240Hz. Use 180Hz or 300Hz. For PAL emulation, use 150Hz or 250Hz for 50fps PAL.
OR
2.
Verify There's An LCD Saver Algorithm Built Into It Or use a BFI/CRT algorithm that slowly drifts (adds an extra frame, or blends to even/odd voltages), such as the CRT simulator with the LCD Saver mode. You need to stick to BFI or CRT algorithms that have a built-in "LCD Saver mode". The Blur Busters CRT beam simulator has a built-in LCD Saver Mode. A good demo of CRT Simulator is at
https://testufo.com/crt and adjusting the "LCD Saver" setting.
OR
3. Use an OLED. They also behave much better with software BFI and are immune to software-BFI image retention effects.
You don't need both 1 or 2. Just doing 1 or 2 will solve things.
