Home | News
Lesson Materials
Course Information
Resources

Supplemental Assignment 1: Black & White conversion

Assignment Theme: "Epic Skies"

Before chroma, there was luma. Long before we ever had color photographs, photographs were simply based on luminance - levels of brightness - without any sort of hue or saturation. The first photo ever, by Nicéphore Niépce in 1826, was in black and white:

Black and white, of course, came about because of lack of technology, not because it was actually superior to color. The materials initially used for photography were photoreactive to any kind of light, not any specific colors, so the only thing that could be measured was simply how much light there was.

These days of course, everything is in color - there isn't a single camera on the market that records only the luminance information. This is a good thing - color provides a lot more information and can be manipulated in many more ways. However, and here we delve into the subjective-feely part of photography, there's a certain unique aspect that is exclusive to black and white photography. Call it the isolation of monochrominance, the epicness of rich shadows, or just plain old nostalgia - black and white photos are simply attractive to people, for many different reasons.

For this assignment, you'll learn how to convert your images into black and white (or technically, grayscale). There are a few ways to do this. Your first inclination is to use the black and white mode on your camera. "COOOL!! This is so artsy and sophisticated", you might have said the first time around. But this is noobish, and a terrible way to go about making black and white images.

The key to black and white imagery is that, even though your final image has no color, the physical world and the light that actually reaches your camera does have color. By making use of this color by controlling how much different colors factor into the luminance information of the image, you can create stunning B&W images that highlight or contrast select elements.

Start with this plain old color image here:

The quick, easy, and boring way of turning this image to black and white is to simply change the color space to grayscale. To do this, go to Image->Mode->Grayscale. This simply removes all color information from the image, just like your in-camera B&W mode does, and produces an image like this:

Direct Grayscale/Desaturation

Frankly, this is a pretty boring image. Put this side-by-side with the original color photo, and it's readily apparent that this photo doesn't have any cool black and white effects, it's just a boring desatured version of the original:

In the old days of film, photographers could use color filters to allow in only certain colors of light. You might put a red filter on the front of your lens, for example, and then only red light would pass through and reach the film. Then the black and white film wouldn't be representing the brightness of all the light, but the brightness of just the red light. We could do this with our digital cameras, too, but since our cameras can naturally record a full color image, we can achieve the same effect by taking the digital image and looking at only a certain channel of color (recall that for digital images, everything is composed of Red, Green, and Blue color components). Go to Window->Channels, and the Channels palette should show up in your workspace. Click on "Red", or hit Ctrl+1, to select only the Red channel.

Red channel

You can do try this with the other channels as well. Compare them to the original full color image - you'll notice that areas that are very strong in one color appear very bright when you look at that channel. Heavily blue areas are very bright when you look at the blue channel, for example (conversely, they're very dark when you look at the red channel).

Green channel


Blue channel

You can take looking at individual color channels a step further by combining color channels together with a tool called the Channel Mixer. Instead of looking at just the blue channel (100% blue) or just the green channel (100% green), you can use the channel mixer to create a 0% red, 50% green, 50% blue combination instead. Open Channel Mixer by going to Image->Adjustments->Channel Mixer. Check the "Monochrome" box, and input a combination of percentages that total up to 100%. Here's an example with approximately equal proportions of red, green, and blue.

Equal RGB Combination

The image here looks very boring, because it is - this is pretty much taking equal amounts of red, green, and blue together, which is pretty similar to the regular scene without color. In other words, our ordinary grayscale image that comes straight out of the camera or grayscale conversion mode.

Applying 100% on any particular color gives us the same result as looking at only that channel (blue channel, for example):

You can also apply negative percentages. Placing -75% will subtract 75% of the color information, for example. But make sure you implement an extra +75% somewhere to still end up with a net 100%.

By playing around with different combinations of the color channels, you can create results that are much more appealing or interesting than the ordinary grayscale conversion done in your camera or by most image editing applications, achieving that elusive, intangible "Black and White" look, whatever it is. Here's what we ended up with:

Original color; direct grayscale conversion; channel mixer conversion with +175% red, 0% green, -75% blue

Another example showing what mixing color channels can do:

Original Color
 Direct grayscale conversion
Red channel
 Channel Mixer: 25% Red, 25% Green, 50% Blue
Channel Mixer: 70% Red, 40% Green, -20% Blue

Supplemental assignments are extra assignments that can be done for fun, but will also count towards the 6 completed assignments you'll need to pass the class. For this assignment, take a color image and turn it into a black and white image, utilizing the channel mixer to create mixtures of color that give a more interesting result than the plain old direct grayscale. Submit the original color image, the direct grayscale version, and two images created using different channel mixer combinations.

Assignment Summary: