How can I set up an acurate 100w Blub (with LWF)???

[JeffG2]

How can I set up an acurate 100w Blub (with LWF)???

When I use the vray light an give it an accurate size and set the light to Watts and the multiplier to 100 (watts I assume) it is very much brighter that a standard 3dsmax photometric 100w bulb.

Someone could make a tidy sum setting up Vray light scenes with accurate lights and preset cameras...

[CGdiggs]

A quick reply as I dont have the exact numbers handy.

A typical 100w incandescent lamp is highly inefficient and puts out closer to 1 or 2 watts of actual brightness or about 1200 lumens.

[JeffG2]

Wow, that's right around what I was having to put in the vray light to match the photometric bulb. I thought I was crazy.

[Dariusz Makowski (Dadal)]

Its slightly more complicated than that...

I was doing research about it some time ago, wish I could remember more but here we go..

100 Wat < Wat means nothing its just industry standard for ''dummy'' people to know about the power of bulb which actually can be different. Its more like... the consuption of electisity is 100 wat, but the bulb itself got 5 wat and its brighter than a 200 wat bulb... bla bla bla it changes as the technology goes forward so go for lumens if I'm not wrong

So if I'm not wrong u have to look at eee lumens or the other one..cant remember SORY...

As for matching it to real world theres quite lots of work to do... EG, Gamma isse, camera exposure, Vray gamma and so on, U be better off just doing it on ur ''eye'' and as long as ur scene is accurate in units and scale u will be fine...

Also vray let u change the units in vray light setup, so just scroll it down to third position which say W for Wat type 100 and there u go...

If u want to be physically accurate I advice u to pick camera, take image of your room and a lamp that is in it, if U got ''100'' wat lamp, create exact scene in max, with exact lamp, match the lights and go from there...

[thablanch]

Also vray let u change the units in vray light setup, so just scroll it down to third position which say W for Wat type 100 and there u go...
\

You mean type 2 or 3 watts and there you go. The Vray watt referes to the lights produced ( 2 or 3 watts ) and not to the energy consumed ( 100w)

From the Vray Help File:

Lumious power (lm) - total emitted visible light power measured in lumens. When this setting is used, the intensity of the light will not depend on its size. A typical 100W electric bulb emits about 1500 lumens of light.

Luminance (lm/m^2/sr) - visible light surface power measured in lumens per square meter per steradian. When this setting is used, the intensity of the light depends on its size.

Radiant power (W) - total emitted visible light power measured in watts. When using this setting, the intensity of the light does not depend on its size. Keep in mind that this is not the same as the electric power consumed by a light bulb for example. A typical 100W light bulb only emits between 2 and 3 watts as visible light.

Radiance (W/m²/sr) - visible light surface power measured in watts per square meter per steradian. When this setting is used, the intensity of the light depends on its size.


--------------------------------------

My regular GE clear bulbs states 1250 lumens on the box

[Dariusz Makowski (Dadal)]

You mean type 2 or 3 watts and there you go. The Vray watt referes to the lights produced ( 2 or 3 watts ) and not to the energy consumed ( 100w)



--------------------------------------

My regular GE clear bulbs states 1250 lumens on the box

Ha ! Interesting, good to know that thablanch ! Guess I gotta redo the research then hehe

[JeffG2]

Anyone know of a chart of standard studio lights showing their light production in watts?

[thablanch]

I prefer to work in lumens, as when you load an ies file for exemple, the data is in lumens. Easier to compare apples to apples. So if I have a scene with <real> ies lights, I can use vray lights as a complement, and dealing both with lumens values mixes my head a little less....

[JeffG2]

Anyone know of a chart of standard studio lights showing their light production in lumens?

[digitarch]

well, i also don´t get the clue about lm-values. even when using real-word luminaires with ies-files, correct lamp parameters and everything else the spots are way to dark when using vraysun/vrayphysicam.
a luminaire which is valued 1800 lm by the manufacturer isn´t even softly shimmering compared to the sunlight floating through the window. From what gives me the right "optical" balance between sunlight and photometric lights i use 500.000 lm- values depending on the ies-file.
Matthias

[glorybound]

I don't know if you found your chart, but here is one. http://www.cleanenergybrands.com/sho...tchart-pic.jpg

Anyone know of a chart of standard studio lights showing their light production in lumens?

[Macker]

Good find Bobby.

[Vizioen]

http://www.rapidtables.com/calc/ligh...calculator.htm I use this sometimes

[JeffG2]

I saw the active thread title and thought, "well that looks interesting...".

Little did I know that it was my thread from 5 years ago!