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I had thought LEDs produced a poor color spectrum for film. I see the linked site advertises a color temperature "from daylight to tungsten and anything in betw

I had thought LEDs produced a poor color spectrum for film. I see the linked site advertises a color temperature "from daylight to tungsten and anything in between". How is that accomplished (or is my memory of LED's spectrum poor)?

toomuchtodo 12y ago
Have a Home Depot near by? Go in and look at their Cree bulb displays (both warm and daylight colors).
clarry 12y ago
The diode itself produces only a peak in the spectrum. Phosphors are used to convert the light to a wide spectrum. There are different kinds of phosphors, and there can be multiple coatings of different types. So you can also have different qualities -- and the quality can be very good.
- hackuser 12y ago
  > The diode itself produces only a peak in the spectrum. Phosphors are used to convert the light to a wide spectrum. There are different kinds of phosphors, and there can be multiple coatings of different types. So you can also have different qualities -- and the quality can be very good. Thanks for the explanation. I've been learning a little about light sources; based on my limited knowledge, I wouldn't expect that the full spectrum (or spectral power distribution (SPD)) of daylight could be replicated by hacking together LEDs and phosphors, though perhaps the untrained eye would not be cognizant of the difference. Can they really pull off 'daylight'?
  - aidenn0 12y ago
    They've made fluorescent tubes with daylight spectrum for a long time (I recall seeing them available, but expensive in the 90s). Those work with phosphors, so I don't see why an blue LED pumped phosphor couldn't work as well as one driven by a near-UV mercury vapour lamp.
  - aortega 12y ago
    To exactly match daylight you would need all the visible light, plus infrared and UV, and a total power of 1 KW/square meter. The good thing is that the lamp would also work as a space heater.
- slashink 12y ago
  True! Worked a lot in building broadcast studios and i usually went for http://www.bbslighting.com/products/area-48-soft-remote-phosphor http://www.bbslighting.com/products/area-48-soft-remote-phos... due to the Phosphor filter. Wonderful color representation from a small, efficient fixture.
anigbrowl 12y ago
They have both elements and allow you to dial in a ratio between them (just as multicolor LEDs are actually made up of very very small primary LEDs sandwiched together). They're not as good as HMIs or incandescents in terms of quality or power output capability, but they're 'good enough' for many situations where you just need a little extra light and it's more important to get a good shot than to go to a lot of logistic expense to get a perfect one - on a film set, time is money and there are literally hundreds of cost decisions that have to be made every working day. The other thing they have going for them is that almost every film now comes under the hand of a colorist who adjusts the elements of every scene to favor a particular color palette - ideally one that was chosen in advance of photography and that is supported by lighting, costume, and production design. A tightly constrained color palette provides thematic unity and makes a big contribution to a film's 'atmosphere,' and generally takes precedence over photographic realism. The extreme example of this is making a film in black-and-white for aesthetic reasons; although that's a bit extreme for most mainstream audiences, many popular films are almost monochromatic with a strong tint. This creates visual tension and where the plot revolves pretty clearly around heroes and villains, strong visual contrasts underline the moral contrasts of the narrative. Comedies generally have broader colors palettes and colors are more saturated, reflecting the dramatically unpredictable and chaotic interactions of the characters. Anyway, since shooting features on digital media became practical, and high quality digital scans of film stocks became affordable, filmmakers have exerted more and more control over the color of a film Because They Can, and the increasingly minor deficienices of LEDs are that much more likely to be smoothed away in post anyway because the white balance of a scene can be so easily manipulated in the digital realm.
- caf 12y ago
  Once you've seen the Teal And Orange, you can't unsee it.

toomuchtodo 12y ago

Have a Home Depot near by? Go in and look at their Cree bulb displays (both warm and daylight colors).

clarry 12y ago

The diode itself produces only a peak in the spectrum. Phosphors are used to convert the light to a wide spectrum. There are different kinds of phosphors, and there can be multiple coatings of different types. So you can also have different qualities -- and the quality can be very good.

hackuser 12y ago
> The diode itself produces only a peak in the spectrum. Phosphors are used to convert the light to a wide spectrum. There are different kinds of phosphors, and there can be multiple coatings of different types. So you can also have different qualities -- and the quality can be very good. Thanks for the explanation. I've been learning a little about light sources; based on my limited knowledge, I wouldn't expect that the full spectrum (or spectral power distribution (SPD)) of daylight could be replicated by hacking together LEDs and phosphors, though perhaps the untrained eye would not be cognizant of the difference. Can they really pull off 'daylight'?
- aidenn0 12y ago
  They've made fluorescent tubes with daylight spectrum for a long time (I recall seeing them available, but expensive in the 90s). Those work with phosphors, so I don't see why an blue LED pumped phosphor couldn't work as well as one driven by a near-UV mercury vapour lamp.
- aortega 12y ago
  To exactly match daylight you would need all the visible light, plus infrared and UV, and a total power of 1 KW/square meter. The good thing is that the lamp would also work as a space heater.
slashink 12y ago
True! Worked a lot in building broadcast studios and i usually went for http://www.bbslighting.com/products/area-48-soft-remote-phosphor http://www.bbslighting.com/products/area-48-soft-remote-phos... due to the Phosphor filter. Wonderful color representation from a small, efficient fixture.

anigbrowl 12y ago

They have both elements and allow you to dial in a ratio between them (just as multicolor LEDs are actually made up of very very small primary LEDs sandwiched together). They're not as good as HMIs or incandescents in terms of quality or power output capability, but they're 'good enough' for many situations where you just need a little extra light and it's more important to get a good shot than to go to a lot of logistic expense to get a perfect one - on a film set, time is money and there are literally hundreds of cost decisions that have to be made every working day. The other thing they have going for them is that almost every film now comes under the hand of a colorist who adjusts the elements of every scene to favor a particular color palette - ideally one that was chosen in advance of photography and that is supported by lighting, costume, and production design. A tightly constrained color palette provides thematic unity and makes a big contribution to a film's 'atmosphere,' and generally takes precedence over photographic realism. The extreme example of this is making a film in black-and-white for aesthetic reasons; although that's a bit extreme for most mainstream audiences, many popular films are almost monochromatic with a strong tint. This creates visual tension and where the plot revolves pretty clearly around heroes and villains, strong visual contrasts underline the moral contrasts of the narrative. Comedies generally have broader colors palettes and colors are more saturated, reflecting the dramatically unpredictable and chaotic interactions of the characters. Anyway, since shooting features on digital media became practical, and high quality digital scans of film stocks became affordable, filmmakers have exerted more and more control over the color of a film Because They Can, and the increasingly minor deficienices of LEDs are that much more likely to be smoothed away in post anyway because the white balance of a scene can be so easily manipulated in the digital realm.

caf 12y ago
Once you've seen the Teal And Orange, you can't unsee it.