Find it here: Firmware v1.10 for the Pentax K-3

Changes to V1.10:
  • Added Diffraction Correction on Lens Correction.
  • Shortened processing time for Digital Filter and Color Fringe Correction.
  • Improved stability for AWB (Auto white balance) performance.
  • Changed to ISO Bracketing when using Exposure Bracketing on TAv mode
  • Improved stability for general performance.