noisy footage when using low color temperature

[Chris Nuzzaco]

You have to increase the total amount of light when trying this though, correct?

All that cutting out the red and green does is give you an indication that you need more light to get a good exposure. You can't just filter out red and green and expect blue to get less noisy - you actually have to increase the amount of blue there by adding light wattage. Otherwise, you'll be cranking up your digital gain.

Yes thats correct. I figured it would be a given. As for needing more light, its just life. No one ever said great cinematic images came cheap or easy.

There is a technique however that no one ever seems to mention though... You could design a bayer filter sensor that has the over sensitive channels photosites dies mixed with ND (much like color correction ND gels, for example). If you took this route, you could balance each channel individually without causing global light loss. The sensors sensitivity would go down, however, it would be the most sensitive you could possibly have it for shooting under tungsten light and not suffer blue channel noise. This is all due to the channel based filtering, instead of global filtering... As of right now, it seems (I can't say for sure) that Red has designed their Mysterium sensor in this manner, but balanced it for daylight.

Hope that helps!

 

[Joe G.]

The optimum color temperature for the camera is "5500k"?

Are photo lights generally at that temperature? I thought most were 3200k? Isn't that just a problem at the outset? Should we try to get lighting sets closer to 5500?

 

[Mark L. Pederson]

The optimum color temperature for the camera is "5500k"?

Are photo lights generally at that temperature? I thought most were 3200k? Isn't that just a problem at the outset? Should we try to get lighting sets closer to 5500?

I think it's actually 5000k. Close to daylight temp 5600k.

 

[Sarah C.]

Nuttin like re-awakening an old thread.. but I wanted to comment this has been a great read!

And.. heck, I've seen a lot of these woes from images taken on my still cameras. I'm still not clear if it is the engineering of the chip(s) and lens combination(s) or the ghost in the machine...(firmware)--that colors and light sensitivity/balance are optimized for most common photography.. people and landscapes during daylight hours.

~S

 

[Deanan]

Silicon (and even film) is less sensitive in blue so it makes it naturally daylight balanced since there an abundance of blue in daytime light.

When you shoot under very low temperature light, there is less and less blue so in effect you can be underexposing the blue channel significantly. By trying to balance tungsten back to a neutral balance, you end up gaining up the blue channel tremendously.

One way to work around this if you want to go for a very blue look is to mix part of the green and or red channels back into the blue channel (ala channel mixer in photoshop). This will decrease saturation but also reduce the noise in the blue channel from alot of gain.