A "Tener" or 10K (10,000 watt Tungsten) light cooks the air in the cool Southern California night. The large frame with blue cellophane in front of it is called a "Gel" - this gel is identified as "Full CTB" or Color Temperature Blue. When shooting with film you have to compensate for the color temperature that the film stock you are using sees white light. You have Tungsten Balanced Film (3200K) and Daylight Balanced Film (5600K). If you want to make a tungsten light look cooler - like moonlight would appear - if using tungsten film - you have to add a blue filter. Because tungsten film sees tungsten produced light as white - without any coloring in either the warm or cool spectrum. If you are shooting Tungsten film outdoors during the day, you need to use an "85" filter to compensate for the color shift. Tungsten film will shift blue in daylight. Daylight film will shift orange indoors under tungsten light. With digital cameras you don't need these filters - you can adjust the "white balance" of the camera system to adjust warmer or cooler - usually in increments of 100K. As an old-school cinematographer - I still prefer to use filters and the same tools with digital systems as I would film systems. If you capture a digital source - adjusted to make it more cool - this is what you have. If it's too blue, you have to adjust your RAW files to bring it down. I'd rather shoot for normal exposure - get the best possible representation of what is being presented in front of the camera - and make any adjustments needed in post-production. Changing your RAW capture settings to adjust for creative parameters instead of corrective - is called an in-camera effect. Depending on the needs of the film and the creative choices made, in-camera adjustment can be a positive or a negative. It has to be decided on a case-by-case basis.