100W Light Blub

[del82]

Source type: Point
Distribution: Isotropic
Magnitude: Luminous Intesity
Candelas : ????

I found reading Ls Help that one light blub has intensity of 139 cd. If I use this amount, the room stays dark.
Help

[del82]

6000 cd

[Majdi]

A 100W bulb emits a flux of 1360 lumen (Osram lamp).
This gives a uniform intensity in space of 1360/(4x3.14) = 108 candela. Which is not far from the value given in Lightscape.
What is the size of your room?
The height?
What colors and reflectances are the ceiling, walls and floor?
Then I can calculate the lux level on a horizontal plane (illuminance).
To see something on the screen, just boost the brightness in the properties menu. This will only change the screen appearance without changing the real values.
Hope it helps.

[del82]

Majdi, the room is 4x3 meters, height is 2,7 m.
If I boost the brightness than I will have a problem. My materials are always set for brightness/contast level at 50/50 (default).

[del82]

This is Ls block that I used as a luminarie, its a 100W lamp. Point, isotropic distribution.
The room is 4x3x2,7 m.
Reflectance of materials around 70%.
Also I made the cover of the lamp non occlouding, but still the room is black.

[del82]

forgot 140cd intesity

[del82]

Any lightning designers that can help/explain this?!

[del82]

Are these like the real values you would get when illuminting a room with 140cd?

[Arnold Gallardo]

Hmm let me guess you are comparing your impression of a 100 watt lightbulb with your brain and eyes right as to what you get with your render ? have you actually considered how much exposure you will need to get a bright room with a camera?

The reason it is dark is because of the tone mapping in LVS. The tone mapping in LVS is set for mean values rather than mapping the perceptually important tones hence LVS does not know which areas ARE IMPORTANT to YOU. It uses a very simple cut off rate of displaying the computed luminance. This is why the file-properties- tone adjustments are there for because only YOu can tell which areas of the scene are important to you.

[del82]

o.k. I understand this taht I can control the level of brigtness to get disered results, but are thies the real values you would get?!