|Creating An Effective Scientific Poster Presentation|
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Working With Images
Try including a focus image (or series of images) near your title or at the center of your poster. Select a graph, chart, picture, or drawing that will attract your audience's attention and enlarge it so that it will occupy at least 30% of the area of the finished poster.
Where possible, use a graphical presentation, such as a flow chart, graph, model, or photo, in place of a list or paragraph. Although graphics take more time to prepare, they can communicate more efficiently than paragraphs and more memorably than lists. Graphics can be created in many different programs and imported into PowerPoint.
Resolution is the number of pixels that comprise the image, such as 800 x 600. When you scan an image, you can set the dots per inch (dpi) setting in the scanner software. Multiply this dpi setting by the size of the picture vertically and horizontally to determine how many pixels the image will occupy when scanned. For example, if you scan a 5" by 7" photo at 300 dpi, it results in a 1500x2100 pixel image. Scanning at higher resolutions results in a larger file size.
Never ASSUME that an image, however great it may appear on your computer screen, has a high enough resolution for your poster. Most web images are only 72 dpi and will look grainy or pixelated when printed. Your poster requires images that are at least 150 dpi for printing. If you are starting with a digital image, open it using an image-editing program. In Fireworks, use "Modify > Canvas > Image Size" to obtain a dialogue box that shows the height and width of the image (in pixels and in inches) and the corresponding dpi (Fig. 1). In Photoshop, you would use "Image > Image Size" to obtain the same information.
Photos and slides of images that that you do not have in a digital format can be scanned and saved as graphic files. Save the scanned image as a TIF file to save the most information to begin with. It is important to scan your images at the size they will be printed out on your poster. If your image is going to be 8 x 10 inches, then you need to set the scanner for that image size at 150 dpi (dots per inch). If you plan to enlarge the size of the image for your poster after it is scanned, you will need to plan ahead and compensate by scanning at a higher resolution. If you are using "as scanned " image size for your poster, increasing the dpi to 300 or 600 will not make a noticeable difference in the printed image. Line art is an exception. Scan line art at a very high resolution to get the best results. It makes sense to scan your image at a higher resolution, save it in TIF format, and finally use an image-editing program (such as Photoshop or FireWorks) to create copies at a lower resolution for importing into your poster.
You will want to enlarge an image as much as possible to enhance its impact and visibility. No photo, graphic or chart should be smaller than 5" x 7." Remember, when you scale up the size of an image, you need to calculate the corresponding drop in dpi. For example, if you have a 2" x 3" photo at 600 dpi, and enlarge it in PowerPoint to 300% of its original image size, the enlarged image will be 6" x 9" at 200 dpi. Whew! the enlarged image is still within an acceptable resolution for printing! What would the height and width of the image be (in inches) if you want the printed image to be exactly 150 dpi? (Check your answer)
After you have checked the resolution and adjusted the size of your image, import the image into PowerPoint by using the "Insert > Picture > From File" command. When designing a poster to be printed, DO NOT simply cut and paste pictures from other documents or the web! When you copy & paste an image from another document, you may not be capturing the image in the appropriate resolution.
Next Step: Assess Your Poster