[feynman]

I noticed that IES files, obtained from certain manufacturers display the full sphere (blue dots) whereas other files reveal only a partial display that also changes with each click on the "X" to enable the IES file in an emitter. Is this a display bug? If you open the IES files in a text editor, nothing is missing.

CITIZEN Electronics LED 2010


CITIZEN Electronics LED 2012

[Mihai]

Compare both 2010 and 2010 files. Any extra lines in one of them? Other differences?

[feynman]

Compare both 2010 and 2010 files. Any extra lines in one of them? Other differences?

Thanks for asking... maybe this here provides some clues?

First lines from a "new" IES file (where the blue IES sphere displays erratically)

IESNA:LM-63-2002
[TEST]1
[TESTLAB]Radiant Imaging ProSource
[ISSUEDATE]2011/10/31 10:22:06
[TESTDATE]04-10-2011 09:52:10
[MANUFAC]Citizen Electronics CO., LTD.
[LAMP]LED
[_NUMBEROFRAYS]10000000
TILT=NONE
1 1063.6801 1.00 94 361 1 2 0.019 0.019 0.001
1 1 10.73
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
85 86 87 88 89 90 91 92 93...

...376.92078 377.73560 374.21133 370.34460 368.34000 368.10254 371.21442 372.95908 368.93491 364.87073 365.17316 364.00339
358.71198 357.20978 357.21228 356.29498 359.13190 360.50409 355.08273 350.85358 349.96625 345.69461 340.48068 337.96368
339.62585 339.01099 336.09909 331.57501 326.66098 324.56894 322.08444 315.50577 309.71695 308.49969 306.78754 302.27844
297.18701 294.93997 292.17053 288.70621 284.15466 276.45120 269.96255 265.50345 260.91187 255.89290 249.14427 241.66579
237.02426 235.39958 227.75864 219.16287 217.06331 213.99394 209.90479 203.16365 191.17859 183.67511 182.24040 178.22871
169.69547 162.28447 156.75809 147.78741 142.26355 138.47682 131.28326 125.33448 119.19573 112.22715 104.98363 97.25270
90.13416 82.97061 78.04661 72.39776 63.93448 55.94611 50.14729 44.19600 37.53486 30.78123 25.24736 19.96344 15.21940
11.48016 7.77842 4.77403 4.00543 0.00000 0.00000 0.00000 0.00000 0.00000

First lines from an "old" IES file (where the blue IES sphere displays correctly)

IESNA:LM-63-1995
[TEST]
[TESTDATE]06-4-2010 17:23:21
[MANUFAC]
[LAMP]LED
[_NUMBEROFRAYS]10000000
TILT=NONE
1 380.0000 1.00 91 361 1 2 0.007 0.050 0.001
1 1 3.15
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
85 86 87 88 89 90...

...121.62853 120.83653 119.28268 118.04156 117.03103 117.01144 117.28573 117.53591 118.64215 118.81622 118.33018 117.73938
116.75220 116.52388 115.83738 114.35210 113.29259 113.56538 113.88564 113.75452 113.63094 112.61362 110.70560 109.54209
109.56921 109.27232 107.82698 106.42685 105.12695 103.84287 102.91146 102.02678 100.87683 100.80676 100.39004 99.57920
99.33579 97.85126 95.10829 93.42558 92.46101 91.08575 89.97651 88.43923 87.10015 85.97658 84.02635 81.85307 80.47555
79.04980 77.39120 75.15462 73.08156 70.91205 68.89777 68.03719 66.38010 64.11564 62.62508 60.50229 58.12177 55.88218
53.69985 52.16258 50.10610 46.90570 44.32775 42.90276 40.98946 39.00984 36.61049 34.54044 32.08457 29.05071 27.30018
25.60164 22.56779 19.82481 18.61232 16.35615 13.02162 10.32159 7.60122 5.05040 2.72037 2.53952 1.66011 0.25621 0.35945
0.17332 0.00000

I don't know the anatomy of an IES file, but the "new" one has four trailing zeroes in each block, whereas the "old" one has only one. The odd thing is also, that the "new" IES file's sphere (or, rather, random dots) is displayed pointing downwards, whereas the light emits upwards. The "old" IES file's sphere points in the expected direction. If you like, I could also e-mail the two files if they are of any use.