[argyllcms] Re: is my colorimeter broken?

Hmm,
I've found a tungsten bulb to test this with (though it's a rather old one) 

Produktname: Philips CLASSICTONE 60W E27 230V A60 CL
Tc: 2800K
Ra(cd): 100
720lm 60W

My readings were:

1) towards a black surface in a rather (but not quite) dark cupboard:
Result is XYZ: 0.000063 0.000024 0.000071, Yxy: 0.000024 0.398823 0.152360 
 Ambient = 0.0 Lux, CCT = 1206K (Delta E 844.002624)
 Closest Planckian temperature = 999960K (Delta E 184.562801)
 Closest Daylight temperature  = 34999K (Delta E 193.950907)

2) pointed directly at the light bulb  just turned on:
Result is XYZ: 4717.548485 5240.499321 1804.802846, Yxy: 5240.499321 0.401055 0.445513 
 Ambient = 16463.5 Lux, CCT = 3961K (Delta E 41.546625)
 Closest Planckian temperature = 3293K (Delta E 32.139549)
 Closest Daylight temperature  = 3393K (Delta E 30.456772)
I took 13 more readings over the course of a few minutes without much change. I tried variations of distance to the bulb from a few inches to an arm's length. The lux range was between 700 and 23000. I tried shutting the daylight out (put bulb and and reader in a white bucket or a cupboard and close it). Still, the Planckian temperature was always around 3200K. I only got anything near 2800 once. 

All of that with the ambient light adapter on, of course.

Thanks,

Karl.
Result is XYZ: 4253.471889 4515.959677 1708.480062, Yxy: 4515.959677 0.405947 0.430998 
 Ambient = 14187.3 Lux, CCT = 3777K (Delta E 30.615787)
 Closest Planckian temperature = 3298K (Delta E 22.980267)
 Closest Daylight temperature  = 3388K (Delta E 21.182894)
Result is XYZ: 9293.057604 7629.753842 3267.776806, Yxy: 7629.753842 0.460267 0.377887 
 Ambient = 23969.6 Lux, CCT = 2432K (Delta E 40.857009)
 Closest Planckian temperature = 2793K (Delta E 22.857740)
 Closest Daylight temperature  = 2622K (Delta E 24.819379)
Result is XYZ: 6779.544230 6992.365384 2529.911301, Yxy: 6992.365384 0.415877 0.428932 
 Ambient = 21967.2 Lux, CCT = 3570K (Delta E 27.025012)
 Closest Planckian temperature = 3167K (Delta E 19.545443)
 Closest Daylight temperature  = 3239K (Delta E 18.090882)
Result is XYZ: 2961.331466 3480.816800 1116.266942, Yxy: 3480.816800 0.391793 0.460522 
 Ambient = 10935.3 Lux, CCT = 4220K (Delta E 52.606084)
 Closest Planckian temperature = 3269K (Delta E 41.595466)
 Closest Daylight temperature  = 3397K (Delta E 40.055702)
Result is XYZ: 6039.838902 6350.497743 2381.350673, Yxy: 6350.497743 0.408879 0.429910 
 Ambient = 19950.7 Lux, CCT = 3712K (Delta E 29.213073)
 Closest Planckian temperature = 3261K (Delta E 21.680278)
 Closest Daylight temperature  = 3346K (Delta E 19.968345)
Result is XYZ: 1553.337686 1847.814491 578.914583, Yxy: 1847.814491 0.390279 0.464267 
 Ambient = 5805.1 Lux, CCT = 4266K (Delta E 55.127197)
 Closest Planckian temperature = 3226K (Delta E 43.587239)
 Closest Daylight temperature  = 3360K (Delta E 42.128861)
Result is XYZ: 278.693345 333.135559 95.108045, Yxy: 333.135559 0.394227 0.471238 
 Ambient = 1046.6 Lux, CCT = 4220K (Delta E 59.021741)
 Closest Planckian temperature = 3067K (Delta E 46.044001)
 Closest Daylight temperature  = 3185K (Delta E 44.932717)
Result is XYZ: 282.871010 339.435023 96.397713, Yxy: 339.435023 0.393585 0.472288 
 Ambient = 1066.4 Lux, CCT = 4237K (Delta E 59.736475)
 Closest Planckian temperature = 3055K (Delta E 46.644996)
 Closest Daylight temperature  = 3173K (Delta E 45.547473)
Result is XYZ: 181.747428 217.243468 61.250575, Yxy: 217.243468 0.394896 0.472021 
 Ambient = 682.5 Lux, CCT = 4211K (Delta E 59.451730)
 Closest Planckian temperature = 3046K (Delta E 46.290080)
 Closest Daylight temperature  = 3161K (Delta E 45.231679)
Result is XYZ: 5337.099163 6428.983577 1981.987675, Yxy: 6428.983577 0.388207 0.467628 
 Ambient = 20197.2 Lux, CCT = 4321K (Delta E 57.445464)
 Closest Planckian temperature = 3189K (Delta E 45.504924)
 Closest Daylight temperature  = 3327K (Delta E 44.082656)
Result is XYZ: 7449.018329 7542.837374 2591.730458, Yxy: 7542.837374 0.423635 0.428970 
 Ambient = 23696.5 Lux, CCT = 3425K (Delta E 25.504206)
 Closest Planckian temperature = 3061K (Delta E 17.939152)
 Closest Daylight temperature  = 3116K (Delta E 16.836939)
Result is XYZ: 7328.971698 7489.320688 2560.463565, Yxy: 7489.320688 0.421720 0.430947 
 Ambient = 23528.4 Lux, CCT = 3474K (Delta E 27.440030)
 Closest Planckian temperature = 3076K (Delta E 19.484918)
 Closest Daylight temperature  = 3138K (Delta E 18.352690)
Result is XYZ: 2020.261782 2264.007749 674.037797, Yxy: 2264.007749 0.407450 0.456609 
 Ambient = 7112.6 Lux, CCT = 3899K (Delta E 48.190201)
 Closest Planckian temperature = 3118K (Delta E 36.725583)
 Closest Daylight temperature  = 3210K (Delta E 35.596975)

On Jun 11, 2009, at 2:42 PM, Graeme Gill wrote:


Karl H. Beckers wrote:
But before I consider dual-booting the Mac, is there a good way to verify I can trust my i1d2? 

Does it have an ambient light adapter ?

If I point my i1d2 with the ambient light adapter on at a standard
tungsten incandescent globe (color temperature nominally that of 'A', about 2870 K), and do an ambient reading (ie. spotread -a -x), I get the following:
Result is XYZ: 1087.581794 939.634246 272.759751, Yxy: 939.634246 0.472867 0.408541 
Ambient = 2951.9 Lux, CCT = 2513K (Delta E 5.610268)
Closest Planckian temperature = 2566K (Delta E 3.186191)
Closest Daylight temperature  = 2245K (Delta E 2.133122)

How does your's compare ? Is it's color temperature and xy values
similar ?

Graeme Gill.

Other related posts: