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Once inCamera's dialog opens, the first thing you should do is select the proper chart type from the pop-up menu:
These five chart types have already been discussed in some detail, so it shouldn't be too difficult to figure out which one to select.
Next, select the proper reference file for your chart:
If you are using the standard ColorChecker chart, you do not need to select a reference file, because inCamera has a reference file for that chart "built in." (The built in file does not contain spectral data though, so if you want to specify your light source, you will have to chose a spectral reference file.) The other chart types will require you to locate the proper file. Reference files for each chart type are described in greater detail earlier in this User Guide.
If the file you select is the wrong type or is not the proper format, you will see a Read Error or a Data Format Error message.
If you are using one of the ColorChecker charts and you have selected a spectral data reference file, you can optimize your profile for your light source. You should select the illuminant that best represents the lighting in your image using the Light Source pop-up menu:
The CIE (Commission Internationale d¹Eclairage) has specified a number of standard illuminants. The D illuminants represent daylight at various color temperatures and are based on actual measurements of daylight. Illuminant A represents incandescent light. Illuminant C is a simulation of average daylight. The F illuminants represent various types of fluorescent illumination. F2 represents a cool white fluorescent lamp, F7 and F8 are broad band (continuous-spectrum) daylight fluorescent lamps, and F11 is a narrow band (line-spectrum) white fluorescent lamp, such as TL84.
Several standard illuminants are built into inCamera, listed with their approximate correlated color temperatures. The lower the color temperature of the light source, the redder the light source and the higher the color temperature, the bluer the light source.
If you choose Custom... from the Light Source pop-up menu, you will be asked to select a custom illuminant file. Custom illuminant files are described in the following section.
Note that the Light Source pop-up menu is not available if your data reference file does not contain spectral data. In that case, the reference file contains XYZ or Lab data that is based on a D50 illuminant. You cannot specify a different light source, but D50 is suitable for many situations.
Power Users Only: Custom Illuminant Files
Two custom illuminant files are installed with inCamera. The file named NorthLightCopyLightUV.txt contains spectral data for a North Light HID copy light with the standard diffuser and optional UF3 UV blocking filter. The file named NorthLightCopyLight.txt is for a North Light HID copy light with the standard lenticular diffuser but without the UV filter.
If you have, or can obtain the necessary spectral data about your light source, you can create your own custom illuminant file. If you wish to make a custom illuminant file, it must contain the relative spectral power distribution of the light source, measured from 380 nm to 730 nm at 10 nm intervals. The data may be formatted in several ways.
One example is illustrated by the file named NorthLightCopyLightUV.txt. The format of the spectral data is defined by the line following the BEGIN_DATA_FORMAT line, which specifies that each line of data contains two fields: SPECTRAL_NM, which is an integer wavelength (nm) of an associated data value, followed by SPECTRAL_RM, which is the corresponding spectroradiometric data value. The data itself follows the BEGIN_DATA line, from 380 through 730 nm at 10 nm intervals, as required. The contents of that file are shown here:
# Copy Light w/lens diffuser+UF3
# Copyright ©2004 Robin D. Myers, all rights reserved.
BEGIN_DATA_FORMAT
SPECTRAL_NM SPECTRAL_RM
END_DATA_FORMAT
#
NUMBER_OF_SETS 36
BEGIN_DATA
380 37.439
390 45.991
400 327.10
410 1644.5
420 3647.1
430 5309.9
440 6127.9
450 6546.9
460 7220.1
470 7467.2
480 7322.8
490 7453.8
500 8276.9
510 8642.7
520 8627.7
530 10730.0
540 12886.0
550 10239.0
560 10692.0
570 11559.0
580 11257.0
590 13151.0
600 15050.0
610 14410.0
620 14053.0
630 14107.0
640 14531.0
650 13402.0
660 11856.0
670 10740.0
680 10152.0
690 8776.6
700 7107.0
710 5879.8
720 5320.9
730 4735.4
END_DATA
The file named NorthLightCopyLight.txt was generated by SpectraShop, a spectral analysis program. It contains additional information that is ignored by inCamera, but since the required information is included, the file can be read by inCamera. The contents of that file are shown here:
BEGIN_RECORD
SPECIMEN_ID1 "Copy Light w/lens diffuser"
SPECIMEN_ID2 ""
SPECIMEN_ID3 ""
MATERIAL ""
MANUFACTURER "North Light Products"
SERIAL ""
PRODUCED ""
SURFACE "Matte"
ORIGINATOR "Robin D. Myers"
CREATED "24.5.04"
COPYRIGHT "©2004 Robin D. Myers, all rights reserved."
NOTES ""
#
INSTRUMENT "EyeOne"
SPECTRUM_TYPE "Emissive"
FILTER "Ambient"
GEOMETRY "d/0"
REFERENCE "Absolute"
ILLUMINANT "N/A"
BACKING "N/A"
NMEASURE 4
ACQUIRE_NOTES "Positioned at center of fixture at 5 feet distance."
#
BEGIN_DATA_FORMAT
SPECTRAL_NM SPECTRAL_RM SPECTRAL_MIN SPECTRAL_MAX SPECTRAL_STDEV
END_DATA_FORMAT
#
NUMBER_OF_SETS 36
BEGIN_DATA
380 7.7725E+2 7.7497E+2 7.8125E+2 2.8321E+0
390 1.5943E+3 1.5909E+3 1.5975E+3 2.8301E+0
400 2.5500E+3 2.5473E+3 2.5561E+3 4.1209E+0
410 3.5938E+3 3.5899E+3 3.5977E+3 3.1689E+0
420 4.7757E+3 4.7723E+3 4.7790E+3 2.9567E+0
430 5.8993E+3 5.8977E+3 5.9029E+3 2.4760E+0
440 6.5438E+3 6.5416E+3 6.5471E+3 2.3973E+0
450 6.9299E+3 6.9258E+3 6.9339E+3 3.3804E+0
460 7.6168E+3 7.6108E+3 7.6257E+3 6.3288E+0
470 7.8704E+3 7.8664E+3 7.8790E+3 5.8855E+0
480 7.7172E+3 7.7123E+3 7.7240E+3 5.6334E+0
490 7.8502E+3 7.8467E+3 7.8573E+3 4.8733E+0
500 8.7162E+3 8.7124E+3 8.7257E+3 6.3452E+0
510 9.0999E+3 9.0943E+3 9.1110E+3 7.5754E+0
520 9.0831E+3 9.0797E+3 9.0900E+3 4.8005E+0
530 1.1311E+4 1.1306E+4 1.1320E+4 6.4211E+0
540 1.3594E+4 1.3590E+4 1.3604E+4 6.6356E+0
550 1.0783E+4 1.0778E+4 1.0791E+4 5.6041E+0
560 1.1260E+4 1.1255E+4 1.1268E+4 5.5479E+0
570 1.2176E+4 1.2168E+4 1.2188E+4 8.8340E+0
580 1.1855E+4 1.1848E+4 1.1866E+4 7.9973E+0
590 1.3874E+4 1.3869E+4 1.3884E+4 7.2020E+0
600 1.5866E+4 1.5861E+4 1.5879E+4 8.9888E+0
610 1.5174E+4 1.5167E+4 1.5183E+4 7.4563E+0
620 1.4800E+4 1.4793E+4 1.4812E+4 8.6302E+0
630 1.4854E+4 1.4848E+4 1.4871E+4 1.0795E+1
640 1.5290E+4 1.5284E+4 1.5301E+4 7.7261E+0
650 1.4087E+4 1.4083E+4 1.4096E+4 5.8558E+0
660 1.2457E+4 1.2449E+4 1.2473E+4 1.1315E+1
670 1.1281E+4 1.1277E+4 1.1290E+4 5.7882E+0
680 1.0673E+4 1.0664E+4 1.0683E+4 7.7113E+0
690 9.2245E+3 9.2156E+3 9.2386E+3 1.0062E+1
700 7.4673E+3 7.4639E+3 7.4698E+3 2.4971E+0
710 6.1848E+3 6.1786E+3 6.1922E+3 6.0046E+0
720 5.5997E+3 5.5979E+3 5.6020E+3 1.9619E+0
730 4.9796E+3 4.9764E+3 4.9846E+3 3.5169E+0
END_DATA
END_RECORD
A third possibility is shown here:
Date: 5/24/2004 Time: 15:50 ILLUMINATION_NAME "Emission" BEGIN_DATA_FORMAT SampleName nm380 nm390 nm400 nm410 nm420 nm430 nm440 nm450 nm460 nm470 nm480 nm490 nm500 nm510 nm520 nm530 nm540 nm550 nm560 nm570 nm580 nm590 nm600 nm610 nm620 nm630 nm640 nm650 nm660 nm670 nm680 nm690 nm700 nm710 nm720 nm730 END_DATA_FORMAT BEGIN_DATA My_Light 3.257189 6.165859 19.269892 21.802994 16.533678 39.975159 57.056049 30.274649 30.155033 32.977394 35.03986 36.617123 37.617252 38.191128 38.476234 39.155827 51.626312 62.044827 42.804649 43.08567 48.201847 44.268539 43.22028 43.416119 42.784763 41.291107 39.292709 36.579609 33.26786 29.675453 26.125034 22.980124 19.86338 16.922205 13.994864 11.727232 END_DATA
This format is similar to the GretagMacbeth ColorChecker spectral reference file format. In this case, the BEGIN_DATA_FORMAT section of the file specifies that all of the measurements will be on one line, following the name of the sample. So, a single line of spectral data follows the BEGIN_DATA line, and includes the measurments from 380 through 730 nm at 10 nm intervals, as required by inCamera.
Your measuring instrument may have come with software that can create a file in one of these formats. If not, the easiest way to make a custom illuminant file that can be used with inCamera, is to copy one of the files that is included with inCamera, and then edit it with any text editor that can save plain (unformatted) text files.
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