I am having a difficult time understanding lighting and exposure within TM. I have “Exposure compensation” unticked so that it does not affect the scene as I have been instructed to have more control over the lighting.
In the first image, I have 4 spotlights set at 300lm at the ceiling which is an unrealistically low setting as most LED ceiling lights are in the 650 to 1200lm range. As you can see the translucent shades at the windows (left side between vanities) are showing no light from the exterior, which is again, unrealistic. The exposure is set to zero to compensate for the overly bright interior ceiling lights.
In the second image, I am showing the ceiling lighting completely off (pay no attention to the glow on the diffuser lens) with the exposure ramped up to 6 which seems reasonable for a scene lit entirely by the outside environment.
In the third image, the ceiling lighting is set to 1lm each which for LED fixtures is impossible to reach. The exposure is still at 6 as in the second example. I must dial the ceiling lights all the way down to 1lm to avoid over-exposing the scene which is not realistic.
What’s the balance here? What am I doing wrong? I have been using Corona Renderer and many other rendering software for years and they never behave in this unnatural way. I’d really like to use TM as it’s so easy and comes with a lot of assets, but I just don’t understand how to achieve a scene lit primarily by the exterior environment with a few interior lights that are set to realistic outputs.
Also, while we’re on the subject, why is it attenuation effects the light output when we are already specifying the light output using lumens?
I understand that most photographers either expose for the exterior or the interior but with this software, I am finding it impossible to do without using ridiculously low lumen settings. I’d like to think TM incorporates a physically accurate rendering engine.
It might be worth mentioning that I work in inches. Could there be a conversion problem here or is this the normal behavior no matter the units?
I’d appreciate any advice. Thanks!
