Introduction to Photoshop

By Ginny Santora (with the assistance of Paul Eggermann)

Our April 11th lecture meeting was provided by our own Paul Eggermann. Paul generously shared his knowledge of the Photoshop program as well as his technical skills to provide us with a great introduction to digital technology. We also are grateful that he was able to bring his computer and provide the overhead equipment that made viewing easy for everyone! We wish to thank Avatech Solutions of New Jersey in East Brunswick for the generous use of their projector. Paul has been involved with computers since the '60s and in 1985 he and Barbara started their own computer business. They sold custom built computers with various computer aided design and graphics programs, including Adobe Photoshop.

Photoshop is an image editing program for Windows and MAC and lists for $700, but it is discounted to about $589. Version 6.0 can be purchased for about $250 on EBay. The upgrade to version 7.0 is $149 so it is possible to get the latest rendition at a reasonable price. PhotoShop LE (Limited Edition) usually comes bundled with a scanner but lacks some of the more advanced functions.

Paul took us for a quick tour of the command bar and a few of the tools that photographers would normally use. Photoshop is a huge program with advanced graphics editing features that are beyond the scope of a one hour introduction. Paul demonstrated various techniques for us, including adjusting the tonal range of an image by applying the Image/Adjust/Levels/RGB sliders. Adjusting Levels changes the range of Blacks___Midtones___Whites contained in an image by converting the almost black pixels to black and the almost white pixels to white. Mid-tone grays also can be darkened or lightened. These changes affect the highlights and shadows without changing the overall color balance. Another method to make tonal adjustments is through Image/Adjust/Levels/AutoLevels or AutoContrast. These automatically find the black point and white point and may be adequate for some pictures. Paul prefers using the RGB Adjusting Levels for finer control. Using Image/Adjust/Curves you can control the color range and tonal balance of the image. Like the Levels dialog box, the Curves dialog box allows you to adjust the entire tonal range of an image. But instead of making adjustments using only three variables (highlights, shadows, midtones), with Curves you can adjust any point along a 0-255 scale while keeping up to 15 other values constant. You can also use Curves to make precise adjustments to individual color channels in an image. You also can adjust Color Balance and Hue/Saturation. The Hue/Saturation command permits you to adjust the hue, saturation, and lightness of either the entire image or of individual color components in an image. Paul showed us the Image/ImageSize/ and /Canvas Size functions, which enlarges or reduces your image. It also changes the resolution and gives the image a bigger border, if desired. Image/Rotate Canvas allows you to rotate the image in fixed or variable increments to overcome such problems as horizons that are not horizontal. This can also be accomplished by using Edit/Free Transform and selecting the corners or sides to rotate or scale the image.

A very useful tool to make changes to an image is the Rubber Stamp. To use it, the operator selects the Rubber Stamp tool and a brush. The Rubber Stamp copies the selected area to a new position in the image. This is a great way to eliminate unwanted things in the background. Paul showed how to rotate a shore scene to keep the water from "running off the edge". He then placed a rectangle around a boat and cropped the picture, making the boat more prominent in the picture. He then picked a brush and used the Burn tool to darken an area that was too bright. Selection tools are a major part of Photoshop. It is possible to select an area of an image and then modify that area without changing the rest of the scene. In addition, a selected area can be copied to another Layer where it can be manipulated independently of the rest of the image. Paul demonstrated on his image of a sculpture, "Deux a Plante", how to move the objects closer to or farther away from each other. In another image of a mother and child stone sculpture, Paul showed how to select the sculpture and apply a Blur Filter to the background to effectively bring the sculpture to the front of the image. Paul selected the Magnetic Lasso selection tool which finds the edge of a color and pretty much sticks to it. The Polygonal Lasso tool will do the same job, only point to point. The shorter the segments, the more accurate it will be. The Magic Wand tool selects colors and will give a much smoother edge, but it is still tedious. By choosing the Quick Mask Mode, it is possible to modify a selection by picking the paintbrush and painting at the edge of the area you wish to have as a selection. Zoom in to do a tight selection. This creates an orange mask over the areas to be selected. Picking the Paint Bucket and applying it to the interior of the outlined area fills it completely. Going back to Normal Mode converts the masked area to a selection that can be saved. For his final demonstration, Paul used a photo of a sculpture in which the sky was of little interest. He opened a photo that had a more interesting sky and copied it into another layer in the sculpture scene. He placed the new layer behind the original, then using selection tools, he identified all the areas in the original scene that contained the bad sky and erased them. Voila! The replacement sky appeared in the scene. Since it was on another layer, it could be moved around to get the best position, independent of the sculpture in the foreground.

Paul ended his presentation by initiating a discussion with questions. We learned that IrfanView is a great viewer and that .jpeg is the best compression for sharing images on the Web. Ten percent 10% quality is needed for an e-mail attachment. Fifty percent quality is needed for a Web site. Photoshop has a Save For Web command that makes this a simple thing to do. Paul also provided us with the following great sites: http://www.flatbed-scanner-review.orghttp://www.dealtime.com http://www.nikon-image.com/eng/http://dell.com/ http://www.us.buy.com/ http://www.ebay.com/ Once again, we give Paul a big THANK YOU for a most informative presentation and for his help in guiding us into the new, exciting world of digital imaging! The author also would like to acknowledge his extensive input into this article by providing detailed instructions and explanations to help clarify and explain the techniques and procedures.