OTOY Forums

More and more often is required for us to simulate a real illumination effect in Architectural visualizations, so many clients give us their lamp specifications, the IES files, and ask us to visualize the real lighting aspects in external or interior representation.

I have learned how to use IES lights in Octane, so for example:
- use a light shape as small as possible
- use real Lumen Lamp values in Power field (setting 1/683 value in Texture Field)
- don't check "Surface Brightness" field
- check "Normalize" field
- Load IES file in "Distribution" field (obviously)

But often I have many doubts about the real Power lamp effect, in many cases I have to multiply the power lamp of about 10 times in order to see the light effect...
So I'm asking if I miss something especially about the scale of my project (I always work using cm units).

I ask if there is an "official" approach and workflow in order to use Octane as a Photometric simulator or if we have to give up these features and advise our clients to not consider our visualization valid for a real light effect evaluation.

Many thanks to anyone who wants to give their support to this question.

Hi Luca,
set the Gamma at 1 for the IES file, it should give you a more correct results.

ciao Beppe

Many thanks, Beppe, also for taking part in this difficult argument.
Now using Gamma = 1 the power of the lamp have a more real congruity.

(could be set at value =1 by default in next release?)

GIOLETS wrote:Many thanks, Beppe, also for taking part in this difficult argument.
Now using Gamma = 1 the power of the lamp have a more real congruity.

(could be set at value =1 by default in next release?)

Gamma=1 in ImageTexture is not an ideal case for material textures.

To further elaborate on what Ahmet wrote, the image texture node is used anywhere an image is loaded. Many textures are actually in gamma 2.2 and is actually far more common than those in gamma 1.0.