 | | High Dynamic Range PhotographyBefore any post processing can occur, the image must be "tone mapped" so that resulting HDR image is viewable and editable. If you recall, tone mapping is the HDR software's way to "compress" the dynamic range to a range that can be displayed using today's media/monitors. So basically the brightest parts of an image are darkened, while the darker areas are lightened up providing more detail in both of these areas and bringing the dynamic range to a more central range.
As you might have guessed, this can create some undesirable effects with your images, such as a flat looking or low contrast images. I have also noted that many HDR images can have a gray (or color) cast that is introduced when the tone mapping is completed. Sometimes it is difficult to see the color cast when the images are generated, but once you do a few of these tweaks I think it will be much more apparent, and the corrective actions are not too difficult. The effect sometimes can look like you are wearing colored sunglasses when viewing the image and they have an unnatural look to them.
My workflow follows like this: I bring the tone mapped image into my photo editor which happens to be Photoshop, but you can do similar changes using Elements or one of the other photo editing packages. First I make myself a copy of the image on a new layer, I do this so I always have the original image to fall back to in case I want to refer to or go back to it (non-destructive editing). Next I will generally do my sharpening at this point, again depending on your editor and the amount of sharpening is dependent on the image.
The key to sharpening to me is not to overdo it. Too much sharpening can cause the image to look hard and unrealistic.
Once the sharpening is complete I will then do a black/white point levels adjustment. In Photoshop there is a tool that lets you use an eyedropper to select the blackest area on your image and one for the whitest area and this will bring the image to a more realistic look.
So for instance an image that has clouds in it you can use the white level selection to pick out the brightest part of the cloud and then with the black level eyedropper you select an area that is dark and this will transform the image as seen in the images above showing the color cast removed. Now sometimes you don't have a pure white area in which to select from and or a black shaded place, in these cases you can use the manual level adjustments to bring some contrast back in and help remove any color casts. I have generated a small video showing me doing this which will help get idea across.
So, we have done some sharpening and color cast correction, lastly I normally will run some noise reduction. After tone mapping you will typically notice more noise in your images especially in the shadowed and sky areas. Run your noise reduction to help make your final images noise free. If you don't already have a noise reduction program there are several great ones out there, Neat Image and Noise Ninja to name a couple or if you have Photoshop it even has a noise reduction filter built in. |
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| The Hundred-Year Lie: How to Protect Yourself from the Chemicals That Are Destroying Your Health
by Randall Fitzgerald |  | In the tradition of Silent Spring and Fast Food Nation, investigative journalist Randall Fitzgerald warns how thousands of man-made chemicals in our food, water, medicine, and environment are making humans the most polluted species on the planet. A century ago in 1906, when Congress enacted the Pure Food and Drug Act, Americans were promised "better living through chemistry." Fitzgerald provides overwhelming evidence to shatter this myth, and many others perpetrated by the chemical, pharmaceutical, and processed foods industries.
Plume (June 26, 2007)
Product Dimensions: 8.4 x 5.2 x 0.7 inches
Paperback: 304 pages | Consider This:- The average American carries a "body burden" of 700 synthetic chemicals
- Chemicals in tap water can cause reproductive abnormalities and hermaphroditic birth
- A 2005 study of lactating women in eighteen U.S. states found perchlorate (a toxic component of rocket fuel) in practically every mother's breast milk
- Lab tests have found that four common food additives-aspartame, MSG, and two coloring chemicals-interact synergistically to produce nerve damage. These additives are commonly found in junk food marketed to children.
- In the past few decades male sperm counts fell by 50 percent, women's tubal pregnancies increased by 400 percent, and girls eight years old and younger began experiencing puberty. Chemicals are redefining what is "normal"
| Editorial Review:
In 1906, Congress passed the US Food and Drug Act and, according to the author, this has led to the "Hundred-Year Lie" that our food and drugs have been investigated and are safe and that the additives and chemicals put in them may actually make them better than the organic, natural variety. As an investigative reporter, Fitzgerald is expert at using scientific documents, articles in science and environmental journals and expert interviews to support his case. He concludes that we cannot rely on the government, science or manufacturers to either protect us or predict the effects of the products we ingest. As a test, Fitzgerald had his own blood analyzed for toxins and, in spite of living in an area of California known for its pure water and air and careful eating habits, he was shocked to find many toxic chemicals in his blood. While many readers will not agree with his conclusion that "Merely by choosing a diet of pure foods and a lifestyle free of synthetics, we can detoxify ourselves and initiate the healing of many degenerative illnesses and diseases," this book will cause any reader to think about the effect of our own voluntary actions on the health of our bodies. His suggestions for practical steps one can take may prove useful as well, although in the paperback afterword, he fears that denial will prevent most people or governments from taking any significant action.
Reviewer: Nola Theiss (Vol. 42, No. 1) |
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