How focus impact depth in AD-96TOF-EBZ device

Hello,

We found "JCD J6920B lens with 940nm bandpass filter" lens used in the AD-96TOF-EBZ kit.

If we opt to fix focus at infinity based on the IR Scene. But considering the lens specification, the hyperfocal length measured was 135cm(1.35m).
If we fix focus for this calculated hyperfocal length distance, then from 67cm to infinity the target scene will be sharper. This will not impact the medium and far depth mode.
But for short-range mode which covers range from 25cm to 80cm, the range below 67cm will not be sharper. So we're not sure how will it impact the depth scene.

I have two queries,
1. Whether infinity focus is followed in the AD-96TOF-EBZ kit? If not, how we focus the TOF camera in the AD-96TOF-EBZ device.
2. If the infinity focus option is used, will it impact the short-range mode and how to handle the same?


  • 0
    •  Analog Employees 
    on Aug 31, 2020 11:15 AM 2 months ago

    The AD-96TOF-EBZ lens focus is adjusted in near mode to get sharp edges on a checkerboard target at about 50cm from the camera.

    Theoretically, the change is sharpness will result in depth error and a reduction of the depth image resolution. Since the camera was calibrated for them medium and far modes with the focus set in near mode there shouldn't be any additional depth errors just an image resolution degradation as the distance from the camera increases and the edges are getting less sharp.