idea to lower persistence in a 120hz DLP projector

[jlafarga]

Hello everyone, I have an infocus IN112 DLP projector(probably one of the cheapest 120hz low res projectors you can buy), I haven't checked its color wheel yet but if it were a 6 segment (RGBRGB) wheel would it be possible to lower its persistence if I blocked one of the RGB halves with black tape? I don't mind it halving its brightness (I already think its too bright and always find myself lowering it).

Saludos everyone!
JLafarga

[Chief Blur Buster]

Hello everyone, I have an infocus IN112 DLP projector(probably one of the cheapest 120hz low res projectors you can buy), I haven't checked its color wheel yet but if it were a 6 segment (RGBRGB) wheel would it be possible to lower its persistence if I blocked one of the RGB halves with black tape? I don't mind it halving its brightness (I already think its too bright and always find myself lowering it).

Saludos everyone!
JLafarga

This will theoretically work with the following caveats:
1. The wheel makes one cycle per refresh. Otherwise, you will get the multi image artifact of repeat flashes on the same refresh. The problem is modern DLPs spin the color wheel too fast, so you would end up getting PWM artifacts during multiple flashes per refresh.
2. Your color wheel is spinning at exactly 2x during the refresh rate you choose. A 6x wheel would still strobe 3x when you block half of it, so you need a slower 2x 6-segmentcolor wheel (at 60Hz) or 4x color wheel that runs in 2x mode at 120Hz.
3. You block three segments completely out of six to reduce persistence by a further 50%
4. Your color depth will be halved due to impact on temporal dithering.

A much easier way is to enable 3D mode to lower DLP persistence
There is a much easier way to reduce persistence of a cheap 120Hz DLP: Enable 3D mode even for 2D!. When you enable 3D mode on a 120Hz DLP, black frame insertion is enabled as a waiting cycle for LCD shutter glasses to open/close while nothing is displayed. As a side effect, it lowers persistence during 2D use. This occurs on Optoma GT720, GT750 and GT760, as well as some BENQ DLP projectors and a few others. Try that first, it is easier.