Movie 10

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Black and white adjustments

Movie 10

Martin Evening

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www.photoshopforphotographers.com

This PDF is provided free with the Adobe Photoshop CS4 for Photographers book. Not for distribution or resale.

Converting color to black and whiteThe most important tip here is to always shoot in color. Whether you shoot film or shoot digitally, you are always far better off capturing a scene in full color and use Camera Raw or Photoshop to carry out the color to mono conversion. Although having said that, you do need to use the right conversion methods to get the best black and white conversions from your color files.

The dumb black and white conversionsWhen you change a color image from RGB to Grayscale mode in Photoshop, the tonal values of the three RGB channels are averaged out, usually producing a smooth continuous tone grayscale. The formula for this conversion consists of blending 60% of the Green channel with 30% of the Red and 10% of the Blue. The rigidity of this color to mono conversion limits the scope for obtaining the best grayscale conversion from a scanned color original (see Figure 1). The same thing is true if you were to simply desaturate the image or make a Lab mode conversion, copy the Luminosity channel, convert the image back to RGB mode and choose Edit ➯ Paste. There is nothing necessarily wrong with either of these methods, but you are not really making full use of the information contained in the image.

Smarter black and white conversionsIf you capture in color, the RGB master image will contain three different grayscale versions of the original scene and these can be blended together in different ways. One of the best ways to do this is by using the Black & White image adjustment, which while not perfect, can still do a good job of providing you with most of the controls you need to make full use of the RGB channel data when applying a conversion. Black & White image adjustments can be applied to images directly, or by using the Adjustment panel, and the advantage of this is that you can quickly convert an image to black and have the option to play with the blending modes to refine the black and white conversion. Let’s start by looking at the typical steps used when working with the Black & White adjustment controls.

Black & White slider adjustmentsThe Black & White slider adjustments will, for the most part, manage to preserve the image luminance range without clipping the shadows or highlights, unless you apply extreme negative or positive weightings to two or more sliders.

Black and white film conversionsTraditional black and white film emulsions can all differ slightly in the way they respond to different portions of the visual spectrum (as well as the colors we can’t see). This is partly what gives emulsion films their ‘signature’ qualities. So in a way, you could say that film also uses standard formulas for converting color to black and white, and that these too are like rigid grayscale conversions. You may also be familiar with the concept of using strong colored filters over the lens when shooting with black and white film and how this technique can be used to emphasize the contrast between certain colors, such as the use of yellow, orange and red filters to add more contrast to a sky. Well, the same principles apply to the way you can use the Black & White adjustment to mix the channels to produce different kinds of black and white conversions.

Figure1 If you convert direct to Grayscale, Photoshop advises you there are better ways to convert to black and white!

Martin Evening

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1 The following steps show the basic method for converting a full color original photograph into black and white. The Black & White image adjustment can be applied directly by going to the Image ➯ Image Adjustments menu, or you can go to the Adjustments panel and click on the Black & White button (circled) to add a new adjustment layer.

2 To begin with I clicked on the Auto button. This applied an auto slider setting based on an analysis of the image color content. The auto setting usually offers a good starting point for most color to black and white conversions and won’t do anything too dramatic to the image, but this is immediately a lot better than choosing Image ➯ Mode ➯ Grayscale.

Martin Evening

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3 If you don’t like the auto setting result, you can adjust the sliders manually to achieve a better conversion. In this example, I lightened the Reds and Yellows and darkened the Cyans.

4 Lastly, I clicked on the target adjustment mode button (circled) for the Black & White adjustment. This allowed me to move the cursor over particular areas of interest (such as the sky) and dragged directly on the image to modify the Black & White adjustment. This action selects the nearest color slider in the Black & White adjustment panel. Dragging to the left makes the black and white tones go darker and dragging to the right, lighter. The end result was a photograph in which I managed to lighten the sculpture more and increased the contrast in the sky.

Martin Evening

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1 I started with an RGB color image and converted it to monochrome using the Black & White image adjustment. I then added a Color Balance adjustment layer to colorize this RGB/monochrome image. To do this, I went to the Adjustment panel and selected Color Balance. I first of all clicked on the Shadows button and adjusted the Red slider to apply a red cast to the shadows.

Color blend modeYou will notice that I suggest you use the Color blend mode when applying adjustment layers that are intended to color an image. The advantage of using the Color blend mode is that you are able to alter the color component of an image without affecting the luminosity. This is important if you wish to preserve more of the tone levels information.

Split color toning with Color BalanceAlthough the Black & White adjustment contains a Tint option for coloring images, this can only apply a single color overlay adjustment and I have never really found it that useful. It is nice to have the ability to apply a split tone coloring to a photograph and the simplest way to do this is to use the Color Balance image adjustment. The simple controls here make this an ideal adjustment tool for editing RGB images that have been converted to monochrome using the Black & White adjustment, and the Color Balance controls are really quite intuitive. If you want to colorize the shadows, click on the Shadows radio button and adjust the color settings, then go to the Midtones, make them a different color and so on. Note that it is best to apply these coloring effects with the adjustment layer set to the Color blend mode.

Martin Evening

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3 Finally I clicked on the Highlights button and added a yellow cast to the highlights. I also set the adjustment layer blending mode to Color, which helped to preserve the image luminance information.

2 I then clicked on the Midtones button and adjusted the color sliders there to add a green/blue color balance to the midtones. You will notice that I had Preserve Luminosity checked. This helped prevent the image tones from becoming clipped.

Martin Evening

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Black and white outputBlack and white printing should be easy, but if you are printing from RGB files you’ll meet the exact same issues that affect normal color printing. Your ability to match the print to the screen will be dependent on the same factors as always: the accuracy of the monitor calibration, the type of paper you are printing to and the effectiveness of the printer profile you are using. Mind you, with black and white printing there is perhaps more latitude for the color to be off and for you to still be pleased with the results. If you are aiming for a neutral black and white result, then the profile used must be accurate. In theory, if the measured Info panel gray values are all neutral, the print output should be neutral too. If you are using one of the more advanced Epson printers you may be interested to know that if you convert the image to grayscale, you can access the Advanced B&W Photo settings shown in Figure 2 to apply coloring effects via the system print dialog.

Figure 2 This shows the Advanced Color Settings for the Epson 4800 printer when the ‘Advanced B&W Photo’ option is selected in the main Print Settings section of the System print interface. This allows you to select preset black and white output toning options.

Advanced B&W Photo tipsThere are a few things you need to do in order to access and make the most of the Advanced B&W feature for Epson printers. Firstly, this is only available with certain printer models, such as the Epson 4800 that I use in my office. You can make a print using RGB or Grayscale, but the printer driver assumes the image to be in neutral RGB (ignoring any colors), or in Grayscale mode. Normally you would convert to Grayscale first, in which case, the gamma of the Grayscale space you convert to should match the gamma of your RGB workspace (see page 590 in the book). In the Photoshop Print dialog you will want to select Photoshop Manages colors and select an appropriate printer profile and rendering intent (see pages 623–624 in the book). When you click Print, this will take you to the Epson print dialog, where in the Print Settings section you will need to select an appropriate media type, such as Photo Paper > Premium Glossy Photo Paper (to match the profile selected in the Photoshop Print dialog). Note that not all paper media settings support Advanced B&W. Then select the Advanced B&W Photo from the Color menu (page 627 in the book). Having done that, click on the Advanced Color Settings, to access the Print dialog options shown in Figure 2, where the key thing is to leave most of these sliders alone, except to choose a Color Toning method. You can choose a preset color from this menu, click on the color wheel below, or adjust the Horizontal and Vertical values. The Tone setting says ‘Darker’. This is actually the default setting, but you can modify this if you wish.

Martin Evening

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Adobe™ Photoshop™ CS4 for PhotographersThis PDF on digital capture is supplied on the DVD that comes with Martin Evening’s book: Adobe Photoshop CS4 for Photographers. This latest update in the Adobe Photoshop for Photographers series contains 704 pages in full color, plus a DVD containing video tutorials. The book layout has been further improved to make navigation easier and contains updated advice on everything you need to know about using Photoshop, from digital capture to print output, as well as all that is new in Adobe Photoshop CS4.

PDF usageThis PDF extract is available to view and print. You may share this PDF file or any links to the PDF file with others, but the copyright of the material and images remain the property of myself. The contents may not be modified in any way, or used commercially without express permission from the author.

WebsiteThere is a website for the book from where you can find more information and download more PDF sample pages from the book.


To order the bookAdobe Photoshop CS4 for Photographers is published by Focal Press.ISBN: 9780240521251The title is stocked in most major bookstores throughout the world and is also available to purchase from:www.focalpress.com as well as through the on-line bookstores: www.amazon.com and www.amazon.co.uk.

Movie 10

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