Problem with IES light object

[Anonymous]

I'm having an issue using the IES light object in Archicad 19 - apologies if I have put this in the wrong forum.

As far as I understand, the IES object is able to pick up the luminous size of a IES file (if included within the file itself) and is able to generate an illuminated shape to represent these dimensions. This is of particular importance when using IES files to represent fluorescent fittings/strip lighting, as the IES profile must be "stretched" accordingly.

I am currently using an IES file from Fagerhult (http://www.fagerhult.com/Products/DTI/DTI-type-2-Beta/), which I have checked and does contain dimensions for the luminous opening, however when I activate the options in the light object to use the size as given in the source file, it will only render out a small square at 100mm x 100mm - see the attached image. The luminous opening in the IES file is 1.44m x 0.08m x 0.00m. I'm using the Maxon CineRender.

This doesn't cause a problem for point/circular lights, but for rectangular fittings I can't use the IES object to realistically represent the fitting being used.

I spoke to Graphisoft support and was told that the file I am using doesn't have parametric sizes in it, but I have checked and this isn't the case. Almost all of the IES files I've looked at do have sizes in them, but Archicad doesn't seem to be picking this up.

Help?

[Aaron Bourgoin]

i thought an IES profile was actually for a lightbulb, not a specific fixture. Did I miss something?

[Anonymous]

Aaron wrote:
i thought an IES profile was actually for a lightbulb, not a specific fixture. Did I miss something?

I suppose so, as far as I understand IES profiles are to provide the illumination profile for a specific fixture. As it currently stands, it's fine using the IES object for emulating point/spot lights, but in the case of longer fixtures. it's not possible. The IES object alludes to being able to use the sizes provided in the IES file but doesn't seem to want to. In the video from Graphisoft (http://helpcenter.graphisoft.com/videos/archicad/object-libraries/light/archicad18-new-features-new-and-enhanced-light-sources-ies-light/ at about 2:30 in), it specifically mentions this but am yet to find a working example.

Does that clarify the issue?

[Anonymous]

I thought I'd add some extra information.

Attached is a screenshot of the settings as I have them in Archicad.

So I am expecting the glowing shape to be the size as defined in the IES file. Now, according to the IES standard (Section 5.10)

Luminous Dimensions

The following dimensions refer to the luminous (that is, light emitting) opening of the luminaire, not its physical dimensions. They are meant to approximate the luminous opening (either as a luminous area or volume) for lighting calculations.

It does go on to say it's not inteded for renderings, but there are no other dimensions in the standard, so I am assuming this is where Archicad is supposed to be getting sizes from.

So looking in my IES file, in the corresponding line, I have:

IESNA:LM-63-1995
[TEST]
[MANUFAC] Fagerhult
[LUMCAT] 28829
[LUMINAIRE] DTI type 2 Beta 1x49W
[LAMP] 49W
[DATE] 2007-11-12 17:08:31
[OTHER] EULUMDAT file: 28829.LDT
TILT=NONE
1 4300.0 4.300 95 19 1 2 1.44 0.08 0.00

Indicating units in metres (2) and a width (1.44), depth (0.08) and height (0.00).

Output is as in attachment on the first message.

I guess I'm asking if anyone has ever managed to get this feature to work.