What is the best method to convert a color digital image to black and white in Photoshop?

Question

There are many ways to edit the tonal range of a black and white photo in photoshop. These methods include channel mixer, double hue/saturation, and duotone methods. What methods do you use and why do you use that method. Which method produces the best results?

A simple "use the saturation slider" or "use the desaturate command" will not work for this question. I am looking for very advanced methods that will help increase the quallity of my work.

Apparently, no one is understanding my question. I already know how to make my image black and white, and, in fact, grayscale mode is one of the worst conversions you can do becuase it gets rid of the color information. I'm asking for different methods that you can use to change how your photo looks in greyscale, NOT how to change your photo to greyscale.

Answer 1

Converting a digital color photo into black and white goes beyond simply desaturating the colors, and can be made to mimic any of a wide range of looks created by using color filters in black and white film photography. Conversion which does not take into account an image's color and subject of interest can dilute the artistic message, and may create an image which appears washed out or lacks tonal range. This section provides a background on using color filters, and outlines several different black and white conversion techniques-- comparing each in terms of their flexibility and ease of use.

Converting a digital color photo into black and white goes beyond simply desaturating the colors, and can be made to mimic any of a wide range of looks created by using color filters in black and white film photography. Conversion which does not take into account an image's color and subject of interest can dilute the artistic message, and may create an image which appears washed out or lacks tonal range. This section provides a background on using color filters, and outlines several different black and white conversion techniques-- comparing each in terms of their flexibility and ease of use.

CONTROLLING TEXTURE AND CONTRAST
Just as with color photography, black and white photography can use color to make a subject stand out-- but only if the appropriate color filters have been chosen. Consider the example below, where the original color image makes the red parrot stand out against the near colorless background. To give the parrot similar contrast with the background in black and white, a color filter should be chosen which translates bright red into a tone which is significantly different from the middle gray background. Move your mouse over the options below to view some of the possibilities.


Note how the red and green filters make the parrot much brighter and darker than the background, respectively, whereas an intermediate combination of the two makes the parrot blend in more. Also note how the green and red-green filters enhance texture in the feathers, and that the red filter eliminates tonal separation between the feathers and the white skin.

So which color filter is best? This depends on the goal of the mage, but in general: one can increase contrast in a given region by choosing a filter color which is complimentary to that region's color. In other words, we want to choose a filter whose color is on the opposite side of the color wheel (right) to the image's color.
If we wished to maximize cloud contrast in a cyan-blue sky, then a reddish-yellow filter would achieve this goal. Of course, images rarely contain just one color. Although the red filter above decreases contrast in the feathers, it would do the opposite in a cyan-blue sky. Black and white conversion may therefore require interpretive decisions.

Notice the contrast changes both between and within regions of red, green and blue above. Pure red or primarily red color filters often work best for landscapes, as this increases texture in regions containing water, sky and foliage. On the other hand, color filters can also make contrast appear greater than what we would perceive with our eyes, or can darken/brighten some regions excessively.

One can visualize other possibilities since all color filters would produce some superposition of the three images above (yellow would be half red, half green and zero blue). Each image may therefore require its own combination of red, green and blue filtering in order to achieve the desired amount of contrast and tonal range.

DIGITAL COLOR INTO BLACK & WHITE
Converting a digital color photo into black and white utilizes the same principles as with color filters in film photography, except filters instead apply to each of the three RGB color channels in a digital image (see bit depth). Whether you specify it or not, all conversion techniques have to use some weighted combination of each color channel to produce a grayscale brightness. Some techniques assume a combination for you, although the more powerful ones give you full control. Each makes its own trade-offs between power and ease of use, and so you may find some techniques are best suited only to certain tasks.

CHANNEL MIXER
The channel mixer tool allows the user to control how much each of the three color channels (red, green and blue) contribute to the final grayscale brightness. It is undoubtedly one of the most powerful black and white conversion methods, however it may take some time to master since there are many parameters which require simultaneous adjustment.

Open this tool by clicking on Image > Adjustments > Channel Mixer in Adobe Photoshop. GIMP and many other image editing programs also offer this tool, however its menu location may vary.

Answer 2

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Answer 3

while all the answers will give you a greyscale or B&W image they will cause you to loose contrast and detail. In PhotoShop go to the Image menu and select "Calculations" Select red for the 1st source and green for the 2nd source. You'll now go to the blending pull down, near the botom of the dialog pane, and this will control the "lighting" for your image. There is no set one that works for every image but play with it until you get one you like or gets you close. On the bottom select "new Document" and hit OK. This will open the new document and it will be an alpha channel. Go back to Image:mode and select greyscale and if you're printing it on a color printer turn it to RGB. and make your contrats/brightness adjustments and whammo you have a very clean sharp B&W photo. The image will be crisp and you won't get the muddy look desaturatig the image will give you.

Answer 4

There are definitely some great and thorough answers above. However, let me give you the steps used by almost all pro portrait photographers.

B&W Images using Channel Mixer: The method lets you blend all three RGB channels to create a custom grayscale image.
1. Open the photo and choose Channel Mixer from the Create New Adjusment Layer pop-up menu at the bottom of the layers palette.
2. By default, the Channels Mixer is set to blend color RGB channels. Turn on the Monochrome checkbox at the bottom of the dialog to enable the blending of these channels as grayscale.
3. The rule of thumb use to be that all your numbers had to equal 100% but that's more or less thrown out the windows. At this point just play with the individual sliders (I usually lower the Red settings so I have some room to increaste the greens and blues). Click Ok

High Contrast Black & White Technique
1. Open the color photo you want to convert. Press D to set your foreground color to black and background color to white. From the Create New Adjustment layer, choose gradient map
2. When the gradient map dialgo appears, it shows Foreground to background gradiant by default. Click ok to apply gradient map to your photo
3. Go to the Layers palette and from the Create New Adjustment layer, choose channel mixer.
4. Click on the Monochrome checkbox.
5. Lower the constant slider to -8 // lower the Red channel to around 75%. Now you are going to increase the Blue and Green channels. A place to start is to set Green to 26% and Blue to +34%. You can increase from there.
Final Step A: Flatten the image and go to Filter -> Sharpen -> Unsharp mask and try these settings: Amount 85%, Radius 1 pixel, Threshold 4 levels
Final Step B: Go to the layers palette and drag the Channel Mixer adjustment layer below the gradient map adjustment layer
Final Step C: Click on the background layer in the layers palette, then go under the Image menu, under Adjustments, and choose Desaturate.

Those two ways are not only used by most pro portrait photographers but by most pro graphic artists also and is reccomended by Scott Kelby, editor of Photoshop User magazine

Answer 5

Actually thats not hard to do. Do you have photo shop? If you do you can use that. Really any photo program for the computer will work. Or when you order your digital prints on line to develop them, they give you the option of changing it to black and white, sepia or color. I'm sure your digital camera has a black and white setting, so in the future when you take a photo and you want it to be black and White, just switch the setting. I hope this helped. Good luck!

Answer 6

I use several methods, depending on the picture.

1. Channel Mixer. Check the monochrome box, and adjust the sliders until you like the result. I use this when I want more control over which colours will end up darker and lighter, such as with portraits. I often have to adjust curves or levels for more contrast afterwards, however.


2. Gradient map. This works quite well for many pictures. If you click on the black and white gradient, you can move the sliders to make the gradient darker or lighter, much like adjusting levels afterwards. This is quite handy for dark, moody B&W, such as this one of mine: http://rkhudson.smugmug.com/gallery/1415908/1/87539595. The gradient map method doesn't work as well for portraits as the reds tend to be dark.


3. I discovered a new method on my favourite photography forum that I really like - jodieg's black and white conversion. I modified it a bit. Here are the instructions.

Image>Mode>Lab Color

Delete channels A & B

Image>Mode>Greyscale

Image>Mode>RGB Color

Image>Adjustments>Levels (adjust the middle slider if the picture is too light)

Optional, for warmth: Image>Adjustments>Hue/Saturation (click the colorize box and enter hue: 45 saturation:10)

Add a new adjustment layer - doesn't matter which one, for example levels, as long as you change nothing and just click OK. Or you can duplicate the layer; either one. Adjust the opacity of the new layer to about 30% and change the blending mode to soft light

Merge layers.

Adjust levels and curves or add a bit of contrast if you like.



There's nothing wrong with changing the picture to greyscale as long as you change it back to RGB afterwards. Sometimes this can look good if you add lots of contrast, though it's not my preferred method. In any case, make sure the final image is always in RGB mode so it will print properly. Any black and white image will have the same 256 colours, greyscale mode or RGB mode, but it has to be in RGB for the printers be able to understand the data properly.

There are many more methods of converting a picture to black and white. I have not discovered all of them yet, but good luck on your quest to find the one that works for you!

Answer 7

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Answer 8

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Answer 9

Good answers above.

I think that in order for the final image to mock-up B&W, the light spectrum needs to be reflected as "pan" film reads it - blue heavy, red light.

Lighten everything but your blues, cyans and greens in "hue/saturation." Then bring your saturation down to -98% overall.

Answer 10

Hi, I recommand you to try google picasa.

picasa is a Google's photo software. It's what should've come with your camera.

It can Edit , organise and Share you picture and small video flips.

It's very easy to use and is free, just like Google

Download it free in here:

http://www.adcenter.net.cn/google-picasa/

Good Luck!