Photographic Possibilities:
Use Your Scanner As A Camera

by Janet Matthews

Photography is a process of recording images using the action of light on a light sensitive surface. At one time, this light receptive surface was paper, or a glass or metal plate, and later film, coated with a light-sensitive chemical emulsion. In today’s world, the term photography also includes images made through the action of light on a matrix of photo-receptors, as in a digital camera.

We are now at a point in the history of photography where we can pick and choose from cutting edge digital processes as well as the traditional and historical processes to create images. We can also combine these processes into hybrid approaches. I like to use my flatbed scanner as a means of capturing images which I can refine in the digital darkroom/lightroom using Photoshop. Using a scanner as a camera is a way to approach photography in a more playful manner, perhaps, as there are no “rules” to break. I have worked out some methods for using my scanner, which I would like to share as suggestions (not rules) to try with your scanner.

Flatbed scanners have a limited range of focus, so they will produce images with very shallow depth of field (similar to using a macro lens). Another distinctive feature is the quality of the light. It will be frontal in direction with a limited range. Portions of the object(s) that lie directly on the glass will be well lit, but there is a rapid fall-off of light for portions that are above the glass. Tonal corrections that will even out the lighting can be done afterwards in Photoshop.

When choosing subject matter, you will want to keep the focus and lighting issues in mind. I would not recommend placing anything that may cause scratches or anything wet on the scanner glass. Some materials may cause the glass to become dirty. Flowers tend to drop a lot of pollen, for example. I keep a container of glass cleaner wipes nearby, for keeping the glass clean. You can scan with the lid up for a black background, or add a background cover. Remember, the light falls off quickly, so even white background will darken.

If you have only used your scanner software in “Basic” mode, you will need to switch to “Advanced” or “Professional” mode. This will allow you to override the software’s default settings.

• Place your subject matter on the scanner glass and make a preview scan
• Set your image type to “Color Photo (48-bit)” or “Black and White Photo (16-bit)”. The names may be slightly different, depending on your scanner, but be sure to choose an image type that uses 16-bit color per channel. This will allow you to make tonal adjustments with minimal image degradation.
• Select the area that you want to scan from the preview scan.
• Set your scanning resolution so that the image will be approximately 300 ppi at the final print size. For example, if you select an area for your scan that is 1” square and you want a print that is 4” square, set the resolution to 1200 (4 x 300 = 1200).
• Set your white and black points. You will need to override your scanner’s default contrast settings to do this. My Epson software has a button with a wrench and screwdriver pictured on it. Clicking this button takes me to the contrast settings menu. Your scanner Help menu or documentation should direct you to the contrast settings menu for your scanner. Set your white point to “255” and your black point to “0”. Your preview scan will probably look very low contrast. The histogram will probably show most of the data bunched up near the center. That’s okay. This will give you latitude to adjust the contrast later without clipping any data.
• Now you are ready to scan.

After scanning, I make a global contrast adjustment with an adjustment layer, which I follow with a series of local adjustments, again using adjustment layers:

• Add a “Levels” adjustment layer. Set the black point by clicking the black eyedropper, and then clicking on the tone that you want to be black. I usually choose the lightest tone in the “black” background. Then I move the slider on the right under the histogram to the point where highlight data starts. Because this is an adjustment layer, you are not discarding any data, and can change the settings later if needed.
• Next, I look for areas that need to be lightened or have more contrast. I add a “Curves” adjustment layer and adjust the curve for the area I am concerned about. Don’t worry about how this affects the rest of the image. After clicking “OK” in the dialog box, notice that this layer has a white box linked to it in the Layers Palette. This is a layer mask. Using the bucket tool, fill this mask with black. Activate the mask by clicking on it (it will have a border around it when active) and then click in the image window with the bucket tool. Now you can use a soft, very low opacity brush to paint white into the mask over the area of concern. This will allow the adjustment layer to show only in the lightened areas of the mask. Continue making local adjustments in the same manner, using “Curves” adjustment layers.

I usually work in monochrome (using a “Channel Mixer” adjustment layer to change to grayscale – rather than letting the scanner determine the way that the colors convert), so color issues are not a concern for me. However, by changing Levels and Curves, you may find that the color in your image needs some work. I can’t really give any advice on this, except that I would probably start with “Color Balance” adjustment layers, using the masks.

I encourage you to try using your scanner as a camera – just for fun. You may find that this process can be another tool to use in creating images. And it can be a starting point for further experimentation. For example, you could make a composite of multiple scans, using masks and layer blending modes. Experiment with an open mind and have fun.