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blobs into works of art, but AIP4WIN kept holding me back. As it turns out, ccd cameras on amateur telescopes have a few characteristics that make it quite possible for FWAS members to do real science at the dark site or in our back yards. AIP4WIN explains the process. Starting with chapters entitled Basic Image Processing, Digital Image Formats, How to Make Good CCD Images, AIP4WIN makes it clear that to calibrate the data that actually represents the deep sky is the most important aspect of digital image processing. CCD cameras have the unique property of being linear, that is they record exactly the light that falls on their pixels in exactly the proportion of the energy level of that light and the length of the exposure. This is the major departure from film photography where long exposures necessary for capturing dim object quickly runs into the problem of "reciprocity failure". Simply put, film exposures are non-linear. Twice the time of exposure does not mean twice the amount of light energy captured on the film. Astrophotographers have used techniques such as "hypersensitizing" film to reduce the problem, but eventually all film suffers reciprocity failure. CCD cameras never have the problem. Twice the exposure means twice the energy captured by the camera AND it is expressed as a number directly related to the brightness of the object. Magnitude measurements can be done with high levels of precision from amateur ccd cameras. Variable star observations can be recorded and precisely measured. AIP4WIN explains it all and emphasizes the importance of Calibration in the process.
Science aside, however, my goal was to make my images as pretty as possible using published images to grade my work. AIP4WIN actually does an outstanding job with examples and tutorials of getting the most detail out of raw images. Flat fielding, one of the initial downfalls of my images, is explained in detail. Dark field, bias fields, flat darks are all explained with text and tutorials. Then the software turns the most complicated process of combining images to calibrate and extract detail is really terrific. Getting an image to show to your fellow astronomy enthusiasts usually involves operations on 60 or more images. AIP4WIN makes this potentially tedious process easy to understand, easy to accomplish, and easily repeatable for another deep sky object. Once the calibrated image is obtained AIP4WIN includes all the tools for analyzing and manipulating the calibrated image data to turn all those numerical pixel values into a publishable product.
I highly recommend AIP4WIN. The book and the software both for $80 from Willmann-Bell, Inc. (www.willbell.com). I got mine in less than a week using the least expensive shipping option.
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