Why Daylight Balanced Chip?

[David Cho]

I am curious as to the fact that RED's chip is natively daylight balanced. Most cinematographers shooting on film prefer to shoot on tungsten stock because it its a lot easier to light. Would anyone care to give me some background on why the decision was made to make the RED daylight balanced?

Also, will there ever be a firmware upgrade that allows me to shoot tungsten balanced with the same amount of noise as shooting daylight balanced? I have the new firmware (build 20) and did some tests---I was not satisfied with the noise levels under tungsten.

 

[Von Thomas]

I am curious as to the fact that RED's chip is natively daylight balanced. Most cinematographers shooting on film prefer to shoot on tungsten stock because it its a lot easier to light. Would anyone care to give me some background on why the decision was made to make the RED daylight balanced?

Also, will there ever be a firmware upgrade that allows me to shoot tungsten balanced with the same amount of noise as shooting daylight balanced? I have the new firmware (build 20) and did some tests---I was not satisfied with the noise levels under tungsten.

It's a well known fact, to get the best with tungsten lighting you need to add blue to your lights or over the lens. The blue channel is not receiving the same amount of illumination as the red and green channel, turning that lack of illumination into discernable information that the chip cannot accurately translate and causing it to produce blotches of info we call noise.

If I'm wrong, someone please correct me.

Von

 

[David Cho]

Thanks for the reply. I've used an 80C filter before, and it seems to be a good option, however it cuts down the light dramatically. I would also like to know what the exact ISO would be if I used the 80C filter with the RED.

 

[Stephen Gentle]

Silicon is naturally insensitive to blue light. It is impossible to make a sensor that is tungsten balanced unless you made it out of some other material that was more sensitive. But none exists...

 

[Cail Young]

It is impossible to make a sensor that is tungsten balanced unless you made it out of some other material that was more sensitive.

Or severely limit the sensitivity of the other channels optically; but this would make the sensor incredibly light-hungry, which ruins the point.

 

[David Cho]

Thanks for the explanation. That makes some sense. However, I have shot with still cameras (which probably have silicon based chips, correct?) and they produce clean images with both tungsten and dayllght. And also, using dv cameras like the GL2, the images look the same regardless of whether it is tungsten balanced or daylight balanced. Could someone explain to me the difference between the situations with these cameras and the RED?

 

[Rob Castiglione]

Well, the Red does produce clean images under tungsten lights. I have never really noticed any serious problem shooting under Tungsten lights.

I DO agree however that the Red does seem to hit a kind of awesome sweet spot when you shoot under HMIs.

 

[Wesley Scoggins]

Silicon is naturally insensitive to blue light. It is impossible to make a sensor that is tungsten balanced unless you made it out of some other material that was more sensitive. But none exists...

I wouldn't say that no material exists like that. I am sure we'll be able to build a Tungsten tuned sensor given enough time and research, it's just simply easier to squeeze the most out of the technology we currently have, rather than design a completely new sensor from the bottom up.

 

[jbeale]

Keep in mind that all commercial video cameras for the past 30 years or more have used silicon sensors with about the same native spectral response*. Developing a completely new type of sensor is one (very difficult) thing- making it commercially manufacturable and cost-competitive is a very different thing!

*silicon is actually most sensitive in the near-IR around 800 nm wavelength, and (color) silicon-based camera sensors always need a strong IR-block filter to avoid washing out all visible colors (400-700 nm) whenever there is IR radiation present.

 

[David Cho]

Well, the Red does produce clean images under tungsten lights. I have never really noticed any serious problem shooting under Tungsten lights.

I DO agree however that the Red does seem to hit a kind of awesome sweet spot when you shoot under HMIs.

Rob, it does produce clean images when tungsten lights are used. But I'm not talking about the lights themselves, but when the camera white balance is set at 3200K.

 

[Jannard]

Rob, it does produce clean images when tungsten lights are used. But I'm not talking about the lights themselves, but when the camera white balance is set at 3200K.

With Build 20 you can use tungsten lighting and set WB to 3200K and everything is fine. Not sure what the question is.

Jim

 

[Steve Sherrick]

David, you need to provide us with more information.

What were you rating the camera at?
Where are you seeing the most noise? Is your talent fine but backgrounds are noisy?
What color temperature is your meter reading on set?
Are you viewing proxies, ProRes transcodes, or R3D native?
Have you played your clips on a broadcast monitor?
Have you tried setting your WB metadata to 5000K and then color correcting from there?
Have you tried adding fill to shadow areas, perhaps with CTB gelled light and seeing if that helps improve noise levels?

I've seen some really great looking tungsten footage, but it was lit very well. I think the key with tungsten is getting the lighting ratios correct and making sure you are giving the sensor as much information as possible while still maintaining the mood of the shot. This can involve adding some blue spectrum to certain parts of the image. Shadow areas in the background for example.

I would continue to do tests. I think you will find you just have to figure out what the sensor needs to pull off a clean image under tungsten. Build 20 should help too.

 

[Von Thomas]

As mentioned above, tungsten light is pretty the same with ALL digital cameras, where the blue channel receives the least amount of light, and ALL digital cameras provide their best images under daylight.

Von

 

[Stuart English]

Tungsten setting(s)

Tungsten setting(s)

it does produce clean images when tungsten lights are used. But I'm not talking about the lights themselves, but when the camera white balance is set at 3200K.

Are you saying that you are setting White Balance to 3200K but NOT shooting under tungsten lights?

 

[David Cho]

Are you saying that you are setting White Balance to 3200K but NOT shooting under tungsten lights?

Yes, that's what I'm doing. I'm just doing what people have done for ages, which is shooting diffused hmi and balancing under 3200K to get bluish moonlight look.