Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: romullus on 2016-07-31, 15:13:21

Title: CoronaLight - colour temperature and light intensity relation
Post by: romullus on 2016-07-31, 15:13:21
Just noticed that changing colour temperature of CoronaLight, also changes light level quite significantly. Is this expected behaviour or a bug. If former, then i would like to know what causes that?

p.s. going below 3000K light dims dramaticaly and going below 2000K it almost completely dissapears.
Title: Re: CoronaLight - colour temperature and light intensity relation
Post by: Ondra on 2016-08-01, 11:19:53
yes, this is by design, I remember doing it this way for some reason that I cannot remember ;)
Title: Re: CoronaLight - colour temperature and light intensity relation
Post by: romullus on 2016-08-01, 12:03:00
:]
Maybe it has something to do with fact that IRL incandescent lightbulbs change its colour temperature while dimming?
Title: Re: CoronaLight - colour temperature and light intensity relation
Post by: Ondra on 2016-08-01, 12:44:23
AFAIK it is implemented so that the brightest color component is always intensity 1 while other compoenents dim to make the light colored
Title: Re: CoronaLight - colour temperature and light intensity relation
Post by: romullus on 2016-08-01, 15:03:46
Wouldnt it be better to make brightest component >1 and dimmest <1, so average would always be equal to 1? If that's possible, of course. Not a big deal if not.
Title: Re: CoronaLight - colour temperature and light intensity relation
Post by: Njen on 2016-08-02, 02:03:08
The colour and exposure changes that a light experiences when raising its temperature is something that happens naturally IRL. In my opinion, Corona should not change this relationship. If you want bright lights of a certain colour choosing one of the other modes is the answer.

(http://www.seesmartled.com/images/general/led-color-temperature.jpg)
Title: Re: CoronaLight - colour temperature and light intensity relation
Post by: samuelAB on 2016-08-11, 18:48:54
Your statement is inaccurate, this only makes sense for fluorescent lights. 3ds (or Revit?) max provides a check mark for this (dimming light changes color temperature).

For LEDs and halogen lights, there is no relationship between a change in light intensity and a change in color temperature. Only a small subset of lamps (fluorescent) do this, so it's almost irrelevant, especially since fluorescent can't dim.