How to determine distortion parameter for VEGAS Lens Correction Plugin

Vegas_Sebastian wrote on 11/17/2020, 1:05 AM

This little tutorial is about determining the distortion parameter of your camera or optics by using open source software:

Preparation

  • download and install the open source software hugin (http://hugin.sourceforge.net/)
  • print out that image:
  • take a video clip depicting that print out (note: camera should be parallel to print-out to avoid tangential distortion)
  • take a still image from that clip where the print-out is centered, e.g.

Use Hugin's "Lens calibration GUI"

The open source software Hugin is able to determine the 3 parameter of ptlens model (a,b,c):

  • add Image
  • enter any value for focal length and crop factor
  • click button Find lines, if no sufficient number of lines were found:
    • increase edge detection scale
    • and/or decrease minimum len length
  • check ratio buttons
    • a, b, c
  • click optimise button
  • check preview with "Corrected" option and verify that lines are straight
  • if lines are straight, note these 3 parameter (a,b,c) for VEGAS plugin (which are named as k1, k2, k3)

Comments

RogerS wrote on 11/17/2020, 2:58 AM

For already characterized lenses, you can download values to use in Vegas. Be sure to grab the distortion, not the vignetting data, and guess the approximate focal length of the shot.
https://github.com/lensfun/lensfun/tree/master/data/db

alifftudm95 wrote on 11/17/2020, 7:53 AM

nicee

PC DEKSTOP

CPU: Ryzen 9 5900x

GPU: RTX2060 6GB

RAM: 64GB 3200MHZ

Storage:

C DRIVE NVME M.2 1TB SSD GEN 4

D DRIVE NVME M.2 2TB SSD GEN 4

E DRIVE SATA SSD 2TB

F DRIVE SATA SSD 2TB

G DRIVE HDD 1TB

Monitor: BenQ PD2700U 4K HDR