Since the last major post, I have acquired 3 USB microscopes. These are not full-fledged microscopes, but devices that have zoom factors and light sources. One comes with screenshot/video recording software. I used this to examine a phonograph needle on my turntable. I had enough detail to determine the source of a playback problem. As a result, I purchased a new stylus and now enjoy my LP collection.
High Dynamic Range imaging (HDR) has come some way since I first ran across the initial phenomenon in the late 90's. HDR is a file format for images that contains numbers. The numbers represent so much pictorial information, no monitor or printer can display the data in it's entirety. The HDR image is like a digital negative in as much as making a print involves adjusting the enlarger aperture and light source to an exposure level consistent with the photographer's goals. No one exposure represents the negative entirely. Lighter exposures reveal different details than a lower exposure. An HDR image is formed by taking a series of images that vary only in shutter speed, and combining them in a defined way. Think of an unsliced loaf of bread as an image. T he several images represent every nth slice in a sliced loaf. The other slices are filled in using highly educated guesses to get a full, sliced loaf. Each slice represents a specific shutter speed. ...
As a precursor, let me reiterate, these blogs are for intelligent people with a university background and courses in mathematics, engineering, physics and other of the hard sciences. The first HDR image was the result of the independent work of Prof. Paul Debevec, U.C., and Gregory Ward Larson, JPL. Prof. Debevec developed an algorithm to composite several images into one. His work was published in a research paper still available online. In the back of the paper is a Matlab script of the algorithm. Matlab is published by Mathworks, Inc, and is the foremost mathematics laboratory, Matlab is widely used by scientists and professionals in a science related field. One of the unknown benefits in HDR is the ability two construct an HDR image with only two exposures (images) if the same film is used for several images. Prof. Debevec derived an additional algorithm for determining the film character and using that data to reduce the...
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