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Adobe Photoshop 7

The digital darkroom: improve your photographs

 
Rotate your photo
 Crop the image
 Adjust brightness and contrast
 Sharpen the image with the Unsharp Mask
 Repair scratches and blemishes
 Delete the background and use another
 Remove Red Eye

With thanks to Balraj Bector in Brent for use of his image.

 
If you have taken a portrait orientation shot with your camera, rotate the image by selecting Image > Rotate Canvas > 90o clockwise etc.
To improve the composition, consider cropping the image: select the Crop tool, drag a marquee onto the canvas, adjust the edges of the selection by dragging the handles and press Enter to apply changes (or Right-click and choose Crop). Crop image

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Digital images and, especially scans, are often dull with low contrast. A good way to improve the Brightness/Contrast is to use Levels.

TIP: When making technical adjustments use an Adjustment Layer, which allows you to see the effect without changing the original layer until you are ready to apply it permanently by Merging Layers or delete it by dragging the layer to the trash can. A layer in Photoshop is like a piece of acetate overlaying the image. Layers can be turned on or off, deleted or merged with layers above and beneath them.

  • Select Layer > New Adjustment Layer > Levels. A window opens showing a histogram of the image. This reveals the distribution of light values with a range of 256 values or tones, from dark to light. The vertical axis shows the amount.

  • Drag the slider on the left (which makes the image darker) to the beginning of the histogram on the left side, and the one on the right (which makes the image lighter) to the start of the other side (see below). The centre slider allows you to make overall adjustments and may not need moving.

  • Make sure the Preview box is checked so that you can view the changes. When you are happy with the result, click OK. Compare this to the original layer by toggling the visibility icon for the new layer off and on (see 4 below).

 
 
Improve the colour balance of the image if necessary on another Adjustment Layer: Layer > New Adjustment Layer > Colour Balance. Experiment with the RGB sliders and view the effect on Shadows, Midtones and Highlights. Click OK when satisfied.
            

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To sharpen the image use a special filter, but flatten the layers first as sharpening is best done when other image adjustments have been applied: select Layers > Flatten image. On the Filter menu choose Sharpen > Unsharp Mask. There are three settings:

  • Amount controls the degree of sharpening applied to the whole image depending on its size and resolution. Move the slider and preview the changes in the window. If the % is too high the image begins to show artifacts (unwanted break up of pixels). Try 100% to start.

  • Radius determines whether the effect applies to a single pixel or a group: keep settings between 1 and 

  • Threshold excludes parts of the image: a setting of 0 applies the effect globally; a higher setting excludes tones from dark to light. Keep this at 0.

  • Click OK to apply if you are satisfied with the result.
  

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Remove small unsightly blemishes, spots, dust, scratches by using the Healing Brush tool. Select the tool and set the tool options: choose a suitable brush size, for example. Sample an unblemished but similar part of the image by holding down the ALT key (Mac = Option key) and clicking, then place the cursor over the damaged area and click to paint the correction.
   
Use the Eraser tool or Background Eraser tool to remove the background around your subject and open another image e.g. a new location.  NB It is easier, but not essential, for new Photoshop users if the two images are a similar size.    
  Balraj with background erased

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Drag the subject onto the new image using the Move tool and reposition.

Balraj levitating
To remove Red Eye, work on a duplicate layer in case of mistakes: Layer > Duplicate. Zoom in on the eyes to magnify them 200% - 300% for greater accuracy [1]; use the Eyedropper to sample a colour for the iris – try to find the darkest part of the eye or lashes [2]; then select the Brush tool and choose a suitable size [3]. Paint out the red and if appropriate add a highlight as below by sampling the lightest tone on the image, rather than selecting pure white.

 

     

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© RKM 2002 - 2007

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