Here is a more detailed session: dispcal -v -r -yl -K Setting up the instrument Instrument Type: Eye-One Pro Serial Number: 313906 Firmware version: 503 CPLD version: 999 Date manufactured: 19-6-2007 U.V. filter ?: No Measure Ambient ?: Yes Tot. Measurement Count: 8082 Remission Spot Count: 691 Remission Scan Count: 754 Date of last Remission spot cal: Thu Jul 31 08:54:18 2008 Remission Spot Count at last cal: 682 Total lamp usage: 2635.150635 Place the instrument on its reflective white reference Serial no. 313906, and then hit any key to continue, or hit Esc, ^C or Q to abort: // Placing the eye-one on the white reference. Calibration complete Setting up the instrument Instrument Type: Eye-One Pro Serial Number: 313906 Firmware version: 503 CPLD version: 999 Date manufactured: 19-6-2007 U.V. filter ?: No Measure Ambient ?: Yes Tot. Measurement Count: 8082 Remission Spot Count: 691 Remission Scan Count: 754 Date of last Remission spot cal: Thu Jul 31 08:54:18 2008 Remission Spot Count at last cal: 682 Total lamp usage: 2635.150635 Place cap on the instrument, or place in on a dark surface, or place on the white calibration reference, and then hit any key to continue, or hit Esc, ^C or Q to abort: // Having read Graemes reply, the suggestion to place the instrument on the white calibration reference seem wrong. I use the ambient measuring head with cap on. Calibration complete Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: // Placing the eye-one on the display, in its display calibration holder. patch 3 of 3 Current calibration response: Black level = 0.55 cd/m^2 White level = 189.74 cd/m^2 Aprox. gamma = 2.29 Contrast ratio = 346:1 White chromaticity coordinates 0.3450, 0.3444 White Correlated Color Temperature = 4980K, DE to locus = 5.3 White Correlated Daylight Temperature = 4974K, DE to locus = 9.1 White Visual Color Temperature = 5100K, DE to locus = 5.0 White Visual Daylight Temperature = 5203K, DE to locus = 8.7 Effective LUT entry depth seems to be -1073742664 bits The instrument can be removed from the screen. Trying to get rid of the hassle using the ambient reading cap, I try placing the eye-one on an opaque surface (my desktop). Now without the -K setting: dispcal -v -r -yl Setting up the instrument Instrument Type: Eye-One Pro Serial Number: 313906 Firmware version: 503 CPLD version: 999 Date manufactured: 19-6-2007 U.V. filter ?: No Measure Ambient ?: Yes Tot. Measurement Count: 8082 Remission Spot Count: 691 Remission Scan Count: 754 Date of last Remission spot cal: Thu Jul 31 08:54:18 2008 Remission Spot Count at last cal: 682 Total lamp usage: 2635.150635 Place cap on the instrument, or place in on a dark surface, or place on the white calibration reference, and then hit any key to continue, or hit Esc, ^C or Q to abort: // Placing the eye-one on my desktop, in its display calibration holder. Calibration complete Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: // Placing the eye-one on the display, in its display calibration holder. patch 3 of 3 Current calibration response: Black level = 0.62 cd/m^2 White level = 209.56 cd/m^2 Aprox. gamma = 2.42 Contrast ratio = 337:1 White chromaticity coordinates 0.3425, 0.3615 White Correlated Color Temperature = 5126K, DE to locus = 8.0 White Correlated Daylight Temperature = 5129K, DE to locus = 4.1 White Visual Color Temperature = 4946K, DE to locus = 7.7 White Visual Daylight Temperature = 5047K, DE to locus = 3.9 Effective LUT entry depth seems to be -1073742656 bits The instrument can be removed from the screen. Hum, some differences. Then I try the DTP94 with and without -K setting: dispcal -v -r -yl -K Setting up the instrument Instrument Type: DTP94 Serial Number: 100440 Boot version: D929 Software version: DB06 Place cap on the instrument, or place in on a dark surface, or place on the white calibration reference, and then hit any key to continue, or hit Esc, ^C or Q to abort: // Placing the DTP94 on my desktop Calibration complete Setting up the instrument Instrument Type: DTP94 Serial Number: 100440 Boot version: D929 Software version: DB06 Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: patch 3 of 3 Current calibration response: Black level = 0.43 cd/m^2 White level = 153.62 cd/m^2 Aprox. gamma = 2.43 Contrast ratio = 357:1 White chromaticity coordinates 0.3488, 0.3595 White Correlated Color Temperature = 4893K, DE to locus = 3.8 White Correlated Daylight Temperature = 4893K, DE to locus = 1.2 White Visual Color Temperature = 4819K, DE to locus = 3.6 White Visual Daylight Temperature = 4914K, DE to locus = 1.1 Effective LUT entry depth seems to be -1073742664 bits The instrument can be removed from the screen. Without -K setting. dispcal -v -r -yl Setting up the instrument Instrument Type: DTP94 Serial Number: 100440 Boot version: D929 Software version: DB06 Place instrument on test window. Hit Esc, ^C or Q to give up, any other key to continue: patch 3 of 3 Current calibration response: Black level = 0.42 cd/m^2 White level = 156.13 cd/m^2 Aprox. gamma = 2.44 Contrast ratio = 372:1 White chromaticity coordinates 0.3494, 0.3602 White Correlated Color Temperature = 4873K, DE to locus = 3.9 White Correlated Daylight Temperature = 4874K, DE to locus = 1.0 White Visual Color Temperature = 4796K, DE to locus = 3.8 White Visual Daylight Temperature = 4891K, DE to locus = 0.9 Effective LUT entry depth seems to be -1073742656 bits The instrument can be removed from the screen. basiccolor display and DTP94 calibrated on my desktop reports: White Point: Target D50, Achieved delta 0.5 deltab 1.6 Luminence White: 156 cd/m^2 Luminence Black: 0.44 cd/m^2 Contrast: 355:1 basiccolor display and eye-one calibrated on my desktop (I was wrong in my previous post, saying basiccolor display calibrates on the white reference) reports: White Point: Target D50, Achieved delta -4.1 deltab 1.2 Luminence White: 153 cd/m^2 Luminence Black: 0.42 cd/m^2 Contrast: 359:1 Apart from the white point no difference between the DTP94 and eye-one readings using basiccolor display.