Camera Raw basic adjustments

Movie 2

Martin EveningAdobe Photoshop CS4 for Photographers

2

Basic panel controlsThe Basic controls are best approached and adjusted in the order you find them. Start with the white balance adjustments and Exposure and work your way down.

White balanceThe white balance refers to the color temperature of the lighting conditions at the time a photograph was taken and essentially describes the warmth or coolness of the light. Quartz-halogen lighting has a warmer color and a low color temperature value of around 3,400 K, while daylight has a bluer color (and a higher color temperature value of around 6,500 K). If you choose to shoot in raw mode it does not matter how you set the white point settings at the time of shooting, because you can decide later what is the best white balance setting to use. Camera Raw was first designed by Thomas Knoll, one of the original creators of the Photoshop program. Thomas has cleverly used two profile measurements, one made under tungsten lighting conditions and another done using daylight balanced lighting. From this data, Camera Raw is able to extrapolate and calculate the white balance adjustment for any color temperature value that falls between these two white balance measurements, as well as calculating the more extreme values that go beyond either side of these measured values. The default white balance setting will normally use the ‘As Shot’ white balance setting that was embedded in the raw file metadata at the time the image was taken. This might be a fixed white balance setting that was used on your camera or it could be an auto white balance that was calculated at the time the picture was shot. If this is not correct, you can try mousing down on the White Balance pop-up menu and select a preset setting that correctly describes the white balance that should be used. Alternatively, you can simply adjust the Temperature slider to make the image appear warmer or cooler and adjust the Tint slider to balance the white balance green/magenta tint bias.

Figure 1 The Camera Raw Basic panel controls. Clicking Auto will apply an auto adjustment and clicking Default will apply the default Camera Raw settings (which will differ according to whether you are editing a raw or non-raw image). Cu Lu can also be used to apply an Auto setting.

Figure 2 WhiBal™ cards come in different sizes and are available for order from RawWorkflow.com.

Martin EveningAdobe Photoshop CS4 for Photographers

3

Using the white balance toolThe easiest way to set the white balance manually is to select the white balance tool and click on an area that is meant to be light gray color. Don’t select an area of pure white as this may contain some channel clipping and produce a skewed result, which is why it is better to sample a light gray color instead. You will also notice that as you move the white balance tool across the image, the sampled RGB values are displayed just below the histogram, and when you click to set the white balance, these numbers should appear even. There are also calibration charts that you can use such as the X-Rite ColorChecker chart, which can be used in carrying out a custom calibration, although the light gray patch on this chart has been regarded as being a little on the warm side. For this reason, you may like to look into a using a WhiBal™ card (Figure 2). These cards have been specially designed for obtaining accurate white point readings under varying lighting conditions.

Color temperature and filmIn the days of color film we basically had just two choices of film emulsion: daylight and tungsten. Daylight film was rated at 6,500 degrees Kelvin and was used for outdoor photography and studio flash, while tungsten film was rated at 3,400 degrees Kelvin and used for photography with artificial tungsten lighting. These absolute values would rarely match the lighting conditions you were shooting with, but they would enable you to get roughly close to the appropriate color temperature of the light you were using in either a daylight/strobe lighting or indoor/tungsten light setting. One could then fine-tune the color temperature by using filters over the camera lens or color gel filters over the lights themselves.

Figure 3 To manually set the white balance, select the white balance tool and find what should be a light gray neutral area and click to update the white balance..

Martin EveningAdobe Photoshop CS4 for Photographers

4

The tone adjustment controls The tone adjustment controls allow you to make further adjustments to the highlight and shadow clipping points as well as the overall tone balance and brightness.

ExposureThe Exposure slider is used to set the overall brightness, so that the photograph looks ‘correctly exposed’. You can use the Exposure slider to visually assess how brightly exposed you want the picture to be and use this as your primary tool for adjusting the image brightness. You can if you like hold down the O A key as you drag the Exposure slider to see a threshold preview that indicates where there might be highlight clipping or you can rely on the highlight clipping indicator shown in Figure 5 to tell you which highlights are about to be clipped.

RecoveryYou don’t have to worry too much about setting the Exposure too bright or clipping the highlights, because the Recovery slider can be used to restore some of the detail which at first may appear lost. The Recovery slider cleverly utilizes the highlight detail in whichever channels contain the best recorded highlight detail and uses this to boost the detail in the weakest highlight channel. There are limits as to how far you can push a Recovery adjustment, but you may be able to recover as much as a stop or more of overexposure. Plus Camera Raw can sometimes use extra tricks such as ignoring digital gain values used to create higher ISO captures. If you hold down the O A key as you drag the Recovery slider you will get to see a Threshold mode preview, which can often make it easier to determine the optimum setting.

BlacksThe Blacks slider is a little less critical, but again I find it useful to hold down the O A key to obtain a threshold mode preview to help determine the point where the shadows just start to clip.

How Camera Raw calculatesCamera sensors have a linear response to light and the unprocessed raw files therefore exist in a ‘linear gamma space’. Human vision on the other hand interprets light in a non-linear fashion, so one of the main things a raw conversion has to do is to apply a gamma correction to the original image data to make the correctly exposed, raw image look the way our eyes would expect such a scene to look (see Digital exposure on pages 174–175 in the book). So the preview image you see in the Camera Raw dialog presents a gamma corrected preview of the raw data, while the adjustments you apply in Camera Raw are in fact being applied directly to the raw linear data. The reason I mention this is to illustrate one aspect of the subtle but important differences between the tonal edits that can be made in Camera Raw to raw files and those that are applied in Photoshop where the images have already been ‘gamma corrected’. Note that in the case of non-raw files, Camera Raw has to temporarily convert the image to a linear RGB space to carry out the calculations.

Martin EveningAdobe Photoshop CS4 for Photographers

5

Fill LightThe Fill Light kind of matches the behavior of the Shadow amount slider in the Shadow/Highlight image adjustment. If you drag the Fill Light slider to the right this adds more lightness to the dark tone areas and lightens the darkest shadow areas. If you overdo this adjustment, it may knock back the contrast too much and you’ll end up with an artificial looking result such as the Figure 4 example.

Suggested order for the basic adjustmentsThe first step should be to set the Exposure to get the overall image brightness looking right, taking care not to introduce too much highlight clipping. If necessary, use the Recovery slider to restore any important detail that may be clipped in the highlight areas (see page 169 in the book). Next, use the Blacks slider to set the shadow clipping, followed by the Fill Light slider should you need to reveal more detail in the shadow areas. The Brightness and Contrast sliders should be used last to fine-tune the image after you have adjusted these four sliders first.

Figure 5 If you click on the clipping indicators in the Histogram panel you will see a colored overlay in the preview image that indicates any shadow and highlight clipping.

Figure 4 Be careful when setting the Fill Light. Shown here is an extreme example of a solarization type effect that can occur with some photos if you apply too much Fill Light.

Martin EveningAdobe Photoshop CS4 for Photographers

6

1 This shows a raw image as viewed in the Camera Raw dialog, using the default settings in the Basic panel. One way to quickly optimize an image is to click on the Auto button. If you then want to reset all the settings you can do so by double-clicking on the individual sliders, or by clicking on the Default button.

2 In this example I adjusted the Exposure to make the photograph look lighter and achieve what looked like the best visual brightness. You don’t have to worry about blowing out the highlight detail because you can use the Recovery slider to restore any highlight detail that may be clipped (but without destroying the exposure effect).

Basic image adjustment procedure

Martin EveningAdobe Photoshop CS4 for Photographers

7

3 The next step was to optimize the shadows. I used the Blacks slider to set the clipping point for the shadow detail and after that I used the Fill Light slider to lighten the darker areas of the photograph such as the bracken in the foreground. Note that as you adjust the Recovery and Blacks sliders, you can hold down the O A key as you drag to see a threshold view of the image, which can help you determine how far to drag to set the correct amount of clipping.

4 And last of all, I used the Brightness and Contrast sliders to fine-tune the tonal balance of the photograph. It is important that you use the Basic adjustment controls in the order suggested here, instead of adjusting the Brightness first and then tweaking the Exposure afterwards.

Martin EveningAdobe Photoshop CS4 for Photographers

8

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.

www.photoshopforphotographers.com

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.