Black and white photography techniques
When converting color images to black & white, a common technique is to control how each color contributes to the resulting image. This is the same idea as using color filters when shooting a black and white film stock.
In the two images below, the left image uses channel blending to use 70% red and 30% green while the right image uses the standard Black & White filter in Sony Vegas. (These shots are from a music video.) Controlling the black and white conversion this way can be used to increase contrast in the image.
*Roll-over the images above to see the other image.
Another way of changing contrast is simply to use curves with a s-shaped curve. The image below shows curves applied to the image above. Roll-over the image to see the image without curves applied.
An interesting way of doing black and white conversions is to use channel blending to decrease contrast and then use curves to add contrast back. Doing this on the right channels can result in an image with increased detail and texture. Michael Kieran talks about this in his book Photoshop Color Correction. Results can be seen below. Note that there is more texture in the ground where the shaft of light hits it.
Adding color to black and white images
Another useful technique for black and white photos is to add a slight tint to it like a sepia tone. Photo.net has a good tutorial on doing exactly this. The key idea is to add tints of slightly different colors for more ‘tonality’ to the image as opposed to a tint of a single color.
The feature films Sin City and The Spirit (upcoming) do very interesting things in their use of black & white. Here is a frame grab from the trailer on Apple’s website (unfortunately the color tints may not show up in the Sin City trailers, even though they are there). I apologize if the colors are not 100% accurate due to compression and possible Quicktime color management issues.
And with saturation boosted to help visualize all the tones in the image:
Aside from the obvious red tie, there is some subtle color tints added to this image… in particular, the sky has a blue tint added to it and the highlights are just a touch yellow.
Play around these techniques and see if they give you more dynamic shots!