3D mode settings can be a little complicated for Optoma ZH39, this tip should be helpful.

Optoma ZH39 Projector

3D Mode
Use this option to disable or enable the 3D function.
Off: Select “Off” to turn off 3D mode.
On: Select “On” to turn on 3D mode.


3D Tech
Use this option to select 3D technology.
DLP-Link: Select to use optimized settings for DLP 3D Glasses.
3D Sync: Select to use optimized settings for IR, RF or polarized 3D Glasses.


3D → 2D

Use this option to specify how the 3D content should appear on the screen.
3D: Display 3D signal.
L (Left): Display the left frame of 3D content.
R (Right): Display the right frame of 3D content.

To enable 3D mode, the input frame rate should be set to 60Hz only, lower or higher frame rate is not supported. And to reach the best performance, resolution 1920×1080 is recommended, please be noted that 4K (3840×2160) resolution is not supported in 3D mode.


Read more:

How to Adjust Brightness Mode of Optoma ZH39 Projector?

Optoma ZH39 Signal Options Adjsutment Tip

Optoma ZH39 Projector Gamma Curve Setting Guide