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Converting Black and White Photos In Photoshop
In this article we're going to look at the principles and techniques of converting black and white photos in Photoshop. I'll explain some of the background information that you need to know, and then dive straight into step-by-step guides on my favourite conversion methods (Camera Raw and B/W adjustment layer). Let's get started...
Shoot in black and white, or convert in post-processing?
I'll just quickly address this question first. Whilst there's something to be said for shooting in black and white, I always find it preferable to stay in colour and then convert the image in post-processing. The vast majority of photographers feel the same. That way, you always have your orignal image, but are free to see how it looks in b/w if you wish.
The tools for converting a colour image are fantastic, especially if you shoot in Raw (more below). So I definitely recommend leaving your options open and not shooting in b/w, even if you have every intention of producing a b/w image!
Black and white is all about colour
The most important thing when converting black and white photos is the colour! Sounds odd, but it's actually the prominence and relationship of colours in the original shot that determines tone and contrast when it's converted to b/w.
In the days of film, photographers would make use of colour filters to enhance or reduce the prominence of certain colours, when shooting in black and white.
The colour of filter they chose depended on the subject. To increase the contrast within a certain colour range, it was necessary to use a filter with a colour from the other side of the colour wheel. For example, a red filter would increase the contrast of blue sky and sea, whilst a blue filter would increase the contrast of red flowers or pink skin.
The Colour Wheel:
Meanwhile, to brighten a certain colour and make it stand out against a background (though reducing its contrast) a filter of the same colour would be used. For example, a red filter lightens pink skin, whilst a blue filter lightens blue sky.
These days, we don't need to shoot on black and white film and carry a plethora of filters. Photoshop enables us to convert a colour image to black and white, then alter the balance of colours to increase contrast/lighten the image in our chosen areas. There are several ways for doing this, but I think that Camera Raw and the black and white adjustment layer (from CS3 onwards) are the best.
Colour sliders in the b/w adjustment layer:
It's almost always best to use 'non-destructive' processing techniques in Photoshop. This means that the changes we make to do not directly alter the original picture, but occur on layers, which can be removed easily if we decide a change hasn't worked. Of course, shooting in Raw is the best option of all, and I definitely suggest having a go with it if you haven't yet (introducing the Raw file format).
Luckily, the b/w conversion methods in Photoshop that give us most control are also non-destructive. I'm not a fan of the results that destructive edits like converting to Grayscale or Lab Color (via Image>Mode) produce.
So, below, I'll explain my 2 favourite options for converting colour images to b/w, using Camera Raw and a black and white adjustment layer.
I recommend this little digital book if you like simple, effective, easy to follow Photoshop techniques: "Photo Nuts and Post".
B/W conversions in Camera Raw
1. Open your image and click on the HSL/Grayscale tab (4th from the left). Tick the 'Convert to Grayscale' box to switch to black and white. It will look pretty flat and faded. Use the 8 colour sliders to increase contrast and brighten your image in the relevant colour areas. Take your time, there's lots of control to increase tonal range here.
2. Go back to the basic tab. Drag the exposure slider to the right as far as possible before the highlights become clipped (the top right triangle in the histogram will turn white when clipping occurs). If necessary, use the Recovery slider a bit.
3. Now use the Blacks slider to deepen the drak areas. Again, watch the histogram to ensure shadows don't become too dark (the top left triangle will turn white). If you need to, use Fill Light to bring back detail.
4. Drag the Clarity slider to the right. This is really important for b/w conversions and I often go to +50 or more.
5. Push the Contrast slider to the right a bit. It's normally best to use the Tone Curve tab for this, but with b/w conversions it's fine.
6. Finally, head over to the Detail tab (3rd from left) and zoom in to 50%. Check for any noise, which is most likely to be in the shadows and blue colour channel. Drag the the Luminosity slider across carefully, until the noise reduces. Use the Luminosity Detail slider (sparingly) to restore a bit of detail. Hit 'Open Image'.
7. Duplicate the background layer and apply sharpening using the Unsharp Mask filter. Done.
Black and white adjustment layer conversion
This adjustment layer is available in Photoshop CS3 onwards and is a really powerful tool. In fact, even though I'm a big fan of Camera Raw, I sometimes leave Raw images in colour (having made some changes to Clarity, Contrast etc) and then convert to b/w using the below method. If you shoot JPEG, this is the way to go...
1. Open your image and duplicate the background layer (Cmd/Ctrl + J).
2. Add a black and white adjustment layer.
There are 3 major options here, all of which are brilliant. The first is to choose from the list of default conversions, which mimic the effect of camera filters. I always try a few of these because, actually, even with the possibility of subtle fine tuning with the colour sliders, they often hit the nail on the head!
In this case, the Lighter filter has done a pretty decent job
Remember, to increase contrast in a particular colour area, choose a filter from the oppoite side of the colour wheel. The red filter preset is often good for making blue skies punchier, whilst the blue filter adds contrast to pink skin. To lighten a colour area, choose a filter that matches the colour. So to lighten skin, choose the red filter (in the above example, a red filter blew out the highlights).
3. The next option is to use the colour sliders. This is always worth doing, even if you have applied a preset filter. It just allows you to fine tune things even more accurately. Play with all of them until you get the result you want.
4. Finally, and this is my favourite option, there's the targeted adjustment tool. Click the pointing hand with arrows pointing left/right, located at the top left.
Find an area of the image that you'd like to lighten/darken and hover the mouse over it. You'll notice the cursor is now a pipette tool. Click and hold the mouse (the cursor becomes a pointing finger with arrows), then drag it to the right to lighten that colour channel, or to the left to darken.
How awesome is that? Very, I think. It takes away the problem that, once an image is converted to b/w, you're not always completely sure which parts of an image the blue, red, green, magenta etc. sliders are going to impact. It's totally intuitive. Just pick a spot to work on and drag the slider.
5. Having tried the presets, tweaked the colour sliders, and tweaked some more with the targeted adjustment tool, hit 'OK'.
6. Next, create a Levels adjustment layer and decide whether the highlights and shadows need to be altered to increase the overall contrast. Make any changes you think are necessary.
7. Go to Filter>Sharpen>Unsharp Mask and enter the paramaters for sharpening. Hit 'OK'. Reduce the opacity of the sharpened layer if necessary.
8. Save the image.
Final Converted Image:
Both Camera Raw and the black and white adjustment layer can be used to make excellent b/w images in Photoshop. Just remember that the strength of a certain colour influences brightness and contrast when converted to b/w. It's also worth using Curves and Levels, or the Basic tab in Camera Raw, to increase contrast more than you usually would for a colour image.