Creating a Black and White Photograph from a Color Negative

File-->Desaturate.  Done.

I wish.

Like most everything in Photoshop, there are so many different ways to create a black and white image from a color negative.  And most of them work pretty well.

This article is going to cover the primary ways that I work to create these black and white tonal relationships.  These techniques can be more time consuming, take more practice, and will create larger files than many of the other techniques, but will give us much more control.

Now creating a black and white image in Photoshop is a bit like putting together a puzzle with a 100 different solutions.  As you begin to create more and more black and white images you will start to get a better feel for which of these pieces/techniques to use and how to use them. 

But for now the first step for us is to figure out where to get these pieces.

Step 1: Finding the Puzzle Pieces (through channels)

Always shoot in color.  If we capture an image in black and white then we are stuck with whatever tonal relationships were originally captured and so we won't have any flexibility in changing them.  We also don't want to just remove all the color from the image.  This is what File-->Desaturate does. 

Instead, we want to use the existing color information to create new tonal relationships within the image that are to our liking.  Here is where channels come in.

Above: Red, Green, Blue and Lightness Channels in Clockwise Order

Each RGB file uses a separate grayscale Red, Green and Blue channel to map out the colors in an image.  These channels are located under the channel tab in the layers palette.  We want to click on each of these layers and copy and paste the information above the color image.  Make sure to label them since it is easy to forget which one is which. 

There is also a fourth channel that can be used, called Lightness in LAB mode.  To access this channel select Image-->Mode-->Lab Color.  Flatten the image and click the channel tab under the layers palette.  Copy the Lightness channel, go back in history to before you converted the image into LAB and paste it into your file.

You will not usually need to copy all of these channels each time you make a black and white.  Many times you will like only the information from one or two channels.  However, it helps to copy all of the channels over the first few times you try this technique.

Step 2: Using Layer Masks

Once we have these layers copied we want to choose the channel that has the best representation of what we want and move it to the bottom of the stack. We then want to add a black layer mask to each layer above it and start painting in the areas of the other channels that we want to show.

Often you’ll want to show a mix of different layers instead of just strictly information from a single channel.  In this case you will want to paint with different levels of grey on the mask depending on how much of the layer you want to show through.  Layer masks themselves are a huge subject that will have to be covered separately.

By using all of these layers of information with layer masks and different opacity brushes you not only have an extreme latitude to work with your images, but you also have the flexibility to come back and alter or edit your creation.

In the case of this image, I decided that I liked the moodiness in the sky of the blue channel the most and so I brought it to the bottom of the stack.  I added the green channel above at 20% to add a little detail and lightness to the grey values and masked off the area around the sun to not blow out any more of the highlights. 

I then wanted some lighter values on the left side of the image everywhere except the main building and so I painted in some of the red channel on the layer mask.

Step 3: Local Adjustments:

Once you have the basis for the tonal look of the image then you want to get into working with lightening/darkening, dodging/burning or tweaking the contrast etc. of the image.  It is important to get the foundation for the image finishes first however.

You can see above that I added a few localized curves to the image.  I did not use these to change the image that much, since the layer channels had already helped me to get pretty close to where I wanted the final image to be.

Channel Mixer:

There is also the channel mixer, which allows you to mix the information from each layer in different percentages.  I use this technique a decent amount.

Under the layer adjustments palette select Channel Mixer.  Click the monochrome button and then play around with the percentages of each different color in ways that add up to 100%.  If you go above 100% you will often begin to clip your whites, so be careful if you do this. 

I believe that this technique is similar to copying each of the red, green and blue channels into your document and mixed them together with different opacities, but without the flexibility of being able to use layer masks.  You can create your entire black and white photo using the channel mixer, or you can copy the effect and use it as a single piece to the puzzle.

The Most Important Step: Rest your Eyes and Come Back Later

Some images will be easy.  But this stuff can sometimes drive you crazy.  The constant back and forth and staring and tweaking will often pound on your eyes and put you in 'the fog'.  If you feel like this there's no point in going on.  You'll most likely just hurt your image and any good progress that you've made already.

Go outside, look around at colorful things, take a 15 minute nap, go to sleep for the night and come back the next day or days later.  You need to see the image from a fresh viewpoint that you can only see with some time away.  There have been so many times where I have woken up the next day and looked at a black and white that I had spent so many grueling hours on and was shocked to see that it looked terrible! 

And then I sat down and whipped up the final image in no time at all.

 Above: The finished image.  Maybe.