# monitor calibration **URL:** \ **Category:** Uncategorized\ **Created:** [July 17, 2002, 12:05pm UTC](https://psychtoolbox.discourse.group/t/monitor-calibration/1444 "2002-07-17T12:05:09Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![zpopse](https://avatars.discourse-cdn.com/v4/letter/z/bb73d2/32.png) [@zpopse](https://psychtoolbox.discourse.group/u/zpopse)\ **Post date:** [July 17, 2002, 12:05pm UTC](https://psychtoolbox.discourse.group/t/monitor-calibration/1444/1 "2002-07-17T12:05:09Z")
Hi all! I recently installed the new Psychtoolbox 2.5. I decided to recalibrate my monitor, but to my surprise I did not obtain what I expected from the calibration (see screendumps below). My system is a PowerMac 8500/180 with a Sonnet Crescendo G4/350 upgrade and an ATi Radeon 32Mb Mac Edition with the latest drivers installed running Matlab 5.2.1 under MacOS 9.2.2. This is the Matlab output during calibration: \*\*\*\*\*\* Which screen to calibrate [0]: Enter RGB values for background as a row vector [190 190 190]: Enter distance from meter to screen (in meters): [0.7]: Enter monitor name: ViewSonic P225ƒ Enter your name: Zoran Describe the calibration: Standard Save codes: 0 - screenX.mat 1 - string.mat 2 - default.mat Enter save code [0]: If colorimeter is off, turn it on Hit any key to proceed past this message and display a box. Focus radiometer on the displayed box. Once meter is set up, hit any key - you will get 10 seconds to leave room. Pausing for 10 seconds ... done Monitor device 1 Monitor device 2 Monitor device 3 Monitor device 1 Monitor device 2 Monitor device 3 CalibrateMonDrvr measurements took 61.9569 minutes Computing linear models Fitting with cubic spline Warning, fit is not non-decreasing Fitting with linear interpolation CalibrateAmbDrvr measurements took 0.793109 minutes \*\*\*\*\*\*