Saturday, December 26, 2009

Part 2: Photography with Imre Z. Balint: Episode 7 - White Balance

Overall, I think that my video covered white balance (WB) quite well, and I don't have a whole lot more to add other than a couple of comments.

First up are the flamingo photos toward the end of the video (starting around 6:12). Now if you look at the values below the photos and then examine the color casts, you might be thinking that something is wrong. The photo of the first flamingo at 3,500 K has a blue cast, but earlier in the video I showed that lower temperatures have a red to yellowish hue. Sames goes for the third pic at 9,000 K, where the image has a stronger red to yellowish hue, yet higher temperatures usually have a blue color cast. What's going on?

The answer is that when I load my RAW file into Photoshop and adjust the WB setting, I'm TELLING the program that the scene has a particular color temperature, thus Photoshop accordingly tires to balance the colors. In other words, if I set the WB on a photo to 9,000 K then the program will assume that the image has a blue cast to it, so the software will try to warm up the photo by auto-magically adding more reds and yellows. Yet another way of putting this is that the color temperature value you set is not what you want the photo (output) to look like, but instead represents what the color temperature of the photo is (input).

The second thing I wanted to comment on is more of a tip that has served me well throughout the years I've been shooting. In general, I always try to get my photographs "right" at the time I take them, versus taking a poorer shot (e.g. over-exposed, wrong WB, etc.) and then trying to fix it later. Doing the latter not only could take more time, but is also risky as there's a chance I may not be able to correct for the flaw, such as an over-exposed shot with blown highlights. So even though I shoot in RAW, I still do my best to expose the image properly and set the WB to where it should be by using either the in-camera presets or my ExpoDisc. And by the way, many digital cameras will still save settings like WB, sharpening, saturation, etc. in the RAW file. So even though I can set my WB (et al.) after I take the shot when I shoot RAW, it still saves me some time and the WB setting will also better represent the color temperature at time of shooting, versus having to make guesses afterwards.

And here is a link to the makers of the ExpoDisc: http://www.expoimaging.com/
Again, I'm not sponsored by them, but I do like their product and I think it does a very good job at getting the white balance correct in regard to the scene I'm shooting.

In next week's episode, I'll be discussing polarizing filters. If you haven't already, please subscribe so you can stay up-to-date with my videos. Happy Holidays!

Web Resources
http://en.wikipedia.org/wiki/Black_body
http://en.wikipedia.org/wiki/Kelvin
http://en.wikipedia.org/wiki/Color_temperature
http://en.wikipedia.org/wiki/Color_balance
http://www.cambridgeincolour.com/tutorials/white-balance.htm
http://digital-photography-school.com/introduction-to-white-balance

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