January 17, 2017 at 2:21PM

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Why do I need to adjust color temperature on camera?

Hey guys, I'm young cinematographer from Turkey. Still studying.. I want to ask one basic question. What's the advantage of adjusting white balance on shooting if we can change the color temperature and do whatever we want later on the post. And even what's the advantage of shooting raw?

4 Comments

Here's an answer based on a number of years shooting RAW on RED (and before that, RAW on Blackmagic Cinema Camera).

Adjusting the camera to the proper white balance when shooting provides the best information for making proper exposure decisions. If you are shooting in overcast daylight (nominally 6500K) and you set the color balance for 2700K (household tungsten lights), first off the monitor image is going to look horribly blue. Secondly, the luma calculations that go into your exposure tools (Waveform, RGB Parade, Video False Color, etc) are all going to be wrong, seeing too much blue and not enough in the orange. It is true that with RAW one can also adjust ISO in post, so in theory if your exposure decisions were wrong, you can fix that, too. But the reality of that is this: if you chop off 1-2 stops of dynamic range because you set the wrong exposure, you are working against your camera, not with it. Thousands upon thousands of REDUSER.net members have posted questions asking "Why is there so much noise in my video?" The answer, 99% of the time, was that they used the wrong references to set exposure, and when they underexposed their images by 3, 4, 5, sometimes 6 stops (no joke!), the great DR specs of the camera couldn't save them from the realities of bad exposure.

As to the advantages of shooting RAW, I would say this: RAW is much more than saving people from making idiotic mistakes. Indeed, as I just argued, RAW does not in fact really save people from that. What it does do is give you the most amazing flexibility to do whatever you want, as long as you do enough things right at the outset: expose properly, light properly, and have a sharp enough lens well enough focused to get the look you want.

January 17, 2017 at 6:27PM

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So in case we cannot shoot raw, if we exposure correctly the image we can change the colour temperature, for example in overcast daylighto we set for 2700K, like you said, we won't loose any information of color on editing, right?

Mete Ağar

January 18, 2017 at 1:21PM

Mete,

I'm afraid you are very confused. If you cannot shoot RAW, then whatever you record is baked in to the pixels you do record. If you are shooting in overcast daylight with a 2700K color balance, the camera is going to throw away 3-4 stops of orange while keeping all the blue. When you go to color correct that error (NLEs like Premiere Pro now have a color temperature slider), what little orange you have left will be noisy and blotchy and no fun at all to work with. On the other hand, if you accurately color balance your camera when you shoot, your colors will have sane video levels that can then be pushed around within the normal boundaries of your codec.

You should always work hard to never need any adjustment in post other than for creative effects. A RED camera, with 16 stops of dynamic range and an codec that doesn't throw away information to fit into a very limited 8-bit or 10-bit 4:2:0 or 4:2:2 color space does provide a certain amount of forgiveness. But not as much as you may think. And that forgiveness is a limited resource that must be shared between the DOP and the colorist. If one is sloppy when shooting, there's no room left for creative grading. A camera that shoots 10-bit log (such as Panasonic GH4 with an external recorder) offers maybe 2 stops to play with. A camera that shoots 8-bit log (such as a Panasonic GH4 without external recorder) gives you maybe one stop to play with. Nothing at all like a RED in that way. Properly exposed, a RED gives the DOP a solid 2 stops to play with and the colorist another 2 stops to play with. That's very cool.

Michael Tiemann

January 18, 2017 at 5:36PM

I'll add to this. With video, your biggest shortcoming is dynamic range in most cases. You lose at least a stop of DR in-camera just to white balance. If working in raw, you can use lens filters to handle most of the white balance and get an extra top in the highlights.

Here's an example I made with a hacked consumer-grade still camera to give you an idea. Top left if the camera's JPEG, bottom right is the processed raw image.
http://www.gcmstudio.com/imagesonly/canon_a540_jpgvsraw.jpg

January 18, 2017 at 8:35AM

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