Wednesday, August 15, 2007
Color Choice Isn't By Chance
Getting color right isn't just about the scientific quantities of the Kelvin scale and wavelengths of light; it's also about emotion and creativity.
Picture by picture, we can change ISO selection, color rendering, white balance, tone and exposure, all of which, in some way, will affect color. The following is a list of examples of camera settings and how they can affect your picture making.
ISO change. This provides broadened control for depth of field and action scenes. But expect color luminance and chrominance to change and noise level and quality to vary as ISO is changed.
Tone curve adjustment. Adjust dynamic range bringing more recorded detail into view; change the appearance of brightness values throughout the tone curve. But also examine color rendering, from shadows to highlights, making adjustments according to your vision. New tools let you make selective changes, dealing with only parts of the picture; get the hang, and you'll be more effectively making images.
Exposure change. Stay within the sensor's dynamic range and get the most appealing color throughout the image. Fine-tune for dynamic range using in-computer software; also, use fill-flash to adjust the scene's dynamic range. Take advantage of every tool in the arsenal.
White balance. If Kelvin temperature is uniformly the same throughout the scene, life is simple! But you can expect a significant variation in Kelvin temperature within many scenes. The fix can be to control color with filtered flash, or fix it in-computer with tools to make selective adjustments. Challenging, yes! Doable, definitely!
Color mode. Color scientists understand the need for compensation and creative choices that bring better color to images. Color modes in your camera provide renderings that are (in the view of the designer) enhancements to a scene or (just as importantly) are compatible with the printer's color range. If you choose a color mode and later decide it's not right, no problem! In-computer change will help, especially if you're working with RAW files. Be aware that such changes can affect the appearance of color and that you may need to make concurrent adjustments to compensate for those changes.
I've gone through changes to how I select in-camera color mode. I originally used Adobe RGB, and then switched to sRGB to have a better “monitor experience.” Now, I've switched back to Adobe RGB. Why? If you shoot in sRGB and later make an in-computer change to Adobe RGB it can affect the appearance of image sharpness due to the (higher contrast) lower color resolution of sRGB. For me, every image begins with Adobe RGB, that is, until there's a color space with more color for better appearance and higher color resolution! Lots of experimenting will help develop your instincts about color.
Changing to a higher ISO typically results in loss of color vibrancy. Get the picture with the higher ISO and change the color later. Adjust a tone curve and make commensurate changes to colors for improved appearance. Didn't get a perfect white balance? Adjust in-computer! Noise raising its ugly head? Use in-camera and in-computer digital tools to help. If exposure's not right, software helps, too.
This sets the stage for examining how to compensate for imaging challenges and also for your personal preferences or needs for making each picture.
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