M22 lies in the constellation Sagittarius, about 2.3 degrees northeast of Lambda Sagittarii. M22 ranks among the six finest globular clusters in the heavens, and is equaled, in the northern sky, only by the great M13 in Hercules. The discovery of M22 is usually credited to the obscure astronomer Abraham Ihle in 1665. In total light, M22 probably ranks in third place among all the known globulars in the heavens. It is also one of the easiest globular clusters to resolve. M22 lies at a distance of about 9600 light years, and the bright central mass is about 50 light years in diameter. Object: M22 (NGC 6656) Coordinates: Right Ascension 18hr 33.3m, Declination -23deg 58m Constellation: Sagittarius Size: 17 minutes of arc Magnitude: 6 Telescope focal length: 500mm Telescope aperture: 80mm Camera: Santa Barbara Instruments ST-6 Exposure: 20 seconds for each image section Observer(s): Greg Latta and Ben Cushwa. (Digital processing by Ben Cushwa) Composite Image Processing Information: This image is a composite image. Starting with the raw image data files each image was examined for content using the ST6OPS camera software to get an idea of where in the final image that particular image would be located. Also, this process eliminated those images that were unable to be used in the final image, leaving only five of the original ten to be processed. Next, each of the remaining images was sharpened using the 'Sharpen' function of the ST6OPS camera software to remove some of the haze around the cluster, and bring out some of the detail in the center of the cluster. After sharpening, each image was log scaled using the ST6OPS camera software to produce a wider range of pixel values. This process must be done at different settings for each image, as each image is slightly different. However, when done properly, each scaled image has quite similar pixel values. The next step in processing was to determine what background and range settings produce the best display for the scaled image. This was done by choosing a central image and setting the background and range for that image. Using a second window of the ST6OPS camera software, each of the remaining images were set and compared to the central image by swapping program windows to compare brightness values. Each processed image was saved with the ST6OPS software under two different file formats using names denoting their position in the final image: .ST6, the camera software format, for bookkeeping purposes; and .TIF, a common graphics format, for further processing. The .TIF images were converted into *.PCX images using Alchemy Mindworks Graphic Workshop. These .PCX images were then adjusted in both contrast and intensity to be certain that the range of grey shades match up. These .PCX files were then pasted to and assembled on a large, blank, white .PCX file using MS-Windows Paintbrush. The bottom two rows of pixels of each image were erased after pasting to remove an apparent artifact from the Graphics Workshop file format conversion process. The assembled image was then cropped using Graphic Workshop to remove the excess white space, and the portions of the remaining image that have no data were colored black to match the background using Paintbrush. Minor touch-up work necessary for the image was then performed using Paintbrush.