4 replies to this topic

[Alienizer]

Hello,

Where can I find document on IES lighting? I have some .ies files, and don't know what all the numbers do at the bottom.

Also, is there docs anywhere on how to implement IES lighting, theory? how it works etc?

Thanks,
Al

[Reedbeta]

I did a quick search for "IES file format" and found this. Does that look like the kind of file you have?

From the look of it, it is just a spherical coordinate grid that tells how much luminous intensity the light puts out in each direction. These numbers can be used directly as direction-dependent light values in a physically-based renderer.

[Alienizer]

Yes it looks like it. Here's what I have from Lithonia Lighting, they have lots of IES data...

IESNA:LM-63-2002
[TEST] 2194061712
[TESTDATE] 1/31/2008
[ISSUEDATE] 11/2/2010
[TESTLAB]
[MANUFAC] Lithonia Lighting
[LUMCAT] 6B1 (13DTT)
[LUMINAIRE] 6" OPEN DOWNLIGHT WITH BLACK BAFFLE.
[LAMPCAT] PLC 13W/27 PHILIPS
[LAMP] ONE 13-WATT DOUBLE TWIN TUBE COMPACT FLUORESCENT, VERTICAL BASE-UP POSITION.
[BALLAST]
[BALLASTCAT]
[DISTRIBUTION] DIRECT, SC-0=1.41, SC-90=1.41
[_LAMPPOSITION] 0 , 0
[_LAMPTYPE] COMPACT FLUORESCENT
[_LAMPWATTAGE] 13
[_LAMPLUMENS] 860
[_MOUNTING] Recessed
[_FAMILY] 6" Baffle Wide Flange
[_PRODUCTID] 945900ae-02db-4cfb-bdf7-ba2d75b1408d
[_INFOLINK] www.lithonia.com/visual/ies/ies.asp?vfile=
[_PRODUCTGROUP] LITHONIA RECESSED
[_TERCAT] Downlight, Commercial
[_TER] 10
TILT=NONE
1 860 1 37 1 1 1 -0.39 0 0
1 1 24
0 2.5 5 7.5 10 12.5 15 17.5 20 22.5 25 27.5 30
32.5 35 37.5 40 42.5 45 47.5 50 52.5 55 57.5 60
62.5 65 67.5 70 72.5 75 77.5 80 82.5 85 87.5 90
0
97 97 98 100 103 105 108 111 115 117 118 118
115 110 103 96 87 77 68 59 50 42 34 27 19 13
9 4 1 0 0 0 0 0 0 0 0

Reedbeta, on 07 February 2012 - 09:05 PM, said:

From the look of it, it is just a spherical coordinate grid that tells how much luminous intensity the light puts out in each direction. These numbers can be used directly as direction-dependent light values in a physically-based renderer.

Any ideas or docs on how that works?

Thanks,
Al

[Reedbeta]

It's too big a topic to cover in a forum post. I'd suggest reading up on the subject of physically-based rendering. There's a great book on the subject that you might pick up. It's pricey, but worth it.

[Alienizer]

Thanks!