Learning IES/Photometry - looking for course or book recommendation

R

RickwTexas

New User
Location
Fort Worth Texas
Occupation
Lighting Specificator
I've been "creating" IES files and various photometry reports for 3 years - without any kind of primer or anyone teaching me. It's challenging to find info on IES files, even after joining IES. I have to create IES files nearly daily for typical office/hospital fixtures, and would sure like to know more than I do. Like; adjusting for lens depth/refraction, compensate for trapped light, how to adjust the LOR, how to look at a Iso-intensity Diagram and tell if it's close or just abstract. I'm not an electrical engineer, but after 3 years I going a base. Book or course, online or in person. Thanks in advance. )
 
RickwTexas said:
I've been "creating" IES files and various photometry reports for 3 years - without any kind of primer or anyone teaching me. It's challenging to find info on IES files, even after joining IES. I have to create IES files nearly daily for typical office/hospital fixtures, and would sure like to know more than I do. Like; adjusting for lens depth/refraction, compensate for trapped light, how to adjust the LOR, how to look at a Iso-intensity Diagram and tell if it's close or just abstract. I'm not an electrical engineer, but after 3 years I going a base. Book or course, online or in person. Thanks in advance. )
Click to expand...
Your creating....how?
Are you manufacturer products or a MAKER?

Toured a plant a life time ago.
Picture a blacked out room, sensors everywhere on the floor or test area.
Test fixture in center point of sensor arrays fixed mounted on plate that could be raised or lowered to different heights to gather the lumen values.
No rules of thumb for trim or lens variations, they simply tested each product they built and generated its IES file.

Went to "https://www.cooperlighting.com/global/resources/ies-file-downloads", they have IES files on everything.

Here is one random one.

IESNA:LM-63-2002
[TEST]P21689
[TESTLAB]INNOVATION CENTER P2
[ISSUEDATE]03/03/2020
[LUMCAT]PD6V120-60V1GC_16PAR38LED
[LUMINAIRE]HALO 6 INCH RECESSED LED LENSED DOWNLIGHT
[MORE]VERTICAL LAMP, SPECULAR CLEAR TRIM AND PRISMATIC GLASS LENS
[LAMPCAT]16E26PAR38
[LAMP](1) PAR 38 LED 16 WATTS
[BALLASTCAT]CHROMA IN0061
[BALLAST]CHROMA IN0061
[OTHER]INPUT WATTS: 15.00, AMPS:.143, VOLTS:120.02, HOURS OPERATED
[MORE]PRIOR TO TESTING: 2, STABILITY: 30 MIN, TOTAL OP TIME: 3 HRS
[MORE]AMB TEMP: 25.4 DEG C
[_MOUNTING]RECESSED
[_ABSOLUTE]NOTE: DATA SHOWN IS ABSOLUTE FOR THE SAMPLE PROVIDED.
[_ABSOLUTELUMENS]606
[MANUFAC] COOPER LIGHTING SOLUTIONS - HALO COMMERCIAL (FORMERLY EATON)
[_SEARCH_APPLICATION] Indoor, Commercial, Corridor, Educational, Entertainment, Hallway, Healthcare, Hospitality, Hotel, Library, Retail, Ambient, Downlight
[_SEARCH_MOUNTING] Ceiling, Recessed
[_SEARCH_SOURCETYPE] LED
[_SEARCH_COLORTEMP] 3000K
TILT=NONE
1 -1 1 37 1 1 1 -0.520833 -0.520833 0.1
1 1 15
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
815 808 800 798 789 762 715 648 563 469
375 293 226 173 134 105 85 70 59 51
43 35 27 17 10 6 4 2 1 1
0 0 0 0 0 0 0
 
Manufacturer. But we don't have a dark room with a goniometer/spectormeter. That is the correct way of doing it. But you can "create" an ies file for a brand new fixture by finding a similar fixture online with a true IES file, and tweaking to meet your specs. This industry shares a lot of files, with no complaining. Often a fixture is designed and originally tested in Asia, and that manuf. will post photometry online for everyone to use. Then other manufs. will use that as a springboard for other fixtures - as long as the basic lighting design is the same (like a 2'x2' troffer with 8000 lumens and basic reflector is going to be the same as everyone elses' 2x2 troffer with 8000 lumens).

What you show above is a great example. So If I design and build a fixture very similar to the Cooper one, there is no reason to spend $5000 on a photometry test. But even if you pull up one of Coopers IES files, the LOR is 100% (impossible in real life) and the candela plot shows no refraction at all. Coopers files are most likely produced using Photopea. It's not a matter of finding an ies file, its a matter of did I try and make it accurate. LED is linear, but light coming from inside a metal fixture will encounter all sort of angles, be diffused by thickness of lens, etc... so there must be a few rules to adjust by.
 
RickwTexas said:
Manufacturer. But we don't have a dark room with a goniometer/spectormeter. That is the correct way of doing it. But you can "create" an ies file for a brand new fixture by finding a similar fixture online with a true IES file, and tweaking to meet your specs. This industry shares a lot of files, with no complaining. Often a fixture is designed and originally tested in Asia, and that manuf. will post photometry online for everyone to use. Then other manufs. will use that as a springboard for other fixtures - as long as the basic lighting design is the same (like a 2'x2' troffer with 8000 lumens and basic reflector is going to be the same as everyone elses' 2x2 troffer with 8000 lumens).

What you show above is a great example. So If I design and build a fixture very similar to the Cooper one, there is no reason to spend $5000 on a photometry test. But even if you pull up one of Coopers IES files, the LOR is 100% (impossible in real life) and the candela plot shows no refraction at all. Coopers files are most likely produced using Photopea. It's not a matter of finding an ies file, its a matter of did I try and make it accurate. LED is linear, but light coming from inside a metal fixture will encounter all sort of angles, be diffused by thickness of lens, etc... so there must be a few rules to adjust by.
Click to expand...
"But you can "create" an ies file" ...
I will have to take your word for that though I don't see how it is possible and the result be accurate.
Your going down a path I can provide no insight for you.

"encounter all sort of angles, be diffused by thickness of lens, etc... so there must be a few rules to adjust by" ...
All the fixtures on Coopers web site had different IES files associated with them if you selected a different trim or lens, etc.
If they are modifying these from a BASE IES file with fudge factors, I would be surprised at that, but in the age of cost cutting I suppose anything is possible.
 
You must log in or register to reply here.
Top