3 Replies Latest reply on Oct 15, 2018 1:30 AM by m0oz

    Defective IR frames for short exposure times (<70usec) [USB2.1]

    m0oz
      Setup Info
      Camera ModelD435
      FW version5.10.3
      SDK version2.16.0

       

      Did anyone else experience issues when setting the IR camera to very short exposure times?
      When connected to a USB2.1 port I observe weird artifacts and damaged frames for exposure times shorter than 70usec

      On a USB3.2 port however, this behavior is not visible.

      Issue Description

      When connected to a USB2.1 port one cannot set the depth exposure time shorter than 70usec.

      Exp times shorter than 70usec will lead to artifacts and over-exposed frames.

       

      Steps to Reproduce

      * Connect a D435 to a USB 2.1 port and open realsense-viewer

      * Enable infra1 stream and set "enable auto exposure" to OFF

      * Set exposure time to something like 100usec and you get unaffected frames

      * Set exposure time to any value lower than 70usec and the frame becomes over-exposed (it looks brighter than at 100usec) and will show artifacts.

       

      ATTENTION: When using a USB3.2 port we could not observe this issue

       

      Example of an IR frame taken at 1usec exposure:

      (Visible salt and pepper artifacts, foggy)

      usb2.1-1us.png

       

      Comparison 60us vs 90us exposure
      USB2.1, 90usec exposureUSB2.1, 60usec exposure
      usb2.1-90us.pngusb2.1-60us.png