photometry

[mskin]

I have created a model in autocad, then file linked it to max.... paying attention to maintaining the correct units. then, after double checking the system units for max, i insert a bunch of photometric lights using web files. i still need to pump them up to 40000 output to get the lights to read. what am i doing wrong/missing and how do i get an accurate lighting model.

[mattclinch]

what are your exposure control settings?

 

and what is the value of the 40000? cd? lm?

[RobNJ73]

Is this a case where you need to do a physically accurate lighting study? Or are you more concerned with capturing the look and feel of the lighting?

 

There is another thread that discusses this (or at least a similar) topic, albeit with VRay as the renderer in question:

 

http://www.cgarchitect.com/vb/29800-ies-real-world-lighting-simulations-vray-2.html

[mskin]

The value is set to cd.

 

I am not completelyt interested in being physically accurate yet, but it has been mentioned here so it would be nice to be able to do it when asked.

 

the scene is set to logorithmic with brightness, contraest, MT and Physcal scale set to 65,50,1,1500 and exterior daylight turned on (there will be an exterior light source - mr sky).

 

I guess that exterior daylight toggle really darkens the scene. im going to try resetting the intensity to the web file and shutting turning that toggle off.

[mskin]

Wow, that seams to make the difference. Now what if i want to use a mr sun? ---

 

the scene is completely washed out. How do i use the mr sun and physically correct photometric lights at once?

[SandmanNinja]

you have to change the 1500 default value (dont have it in front of me) to 80,000 to 120,000. I start in the middle - 100,000

 

That's the value of the brightest light in the scene (i.e. MRSun).

 

As soon as you do that, the lighting level comes inline with reality.