Learn About Your Oral Health. Delta Dental recently conducted the Preventive Dental Care Study, the largest claims study of its kind. We found that even among insured individuals, many people at higher risk for tooth decay or gum disease aren't getting proper preventive dental care. Are you or your family members at higher-risk?
- Straight photography-term used to describe picture making with minimal manipulation of the photograph ic process. -Stress marks-black lines on a photograph ic emulsion caused by friction or pressure.
Photographic cameras were a development of the camera obscura, a device possibly dating back to the ancient Chinese and ancient Greeks, which uses a pinhole or lens to project an image of the scene outside upside-down onto a viewing surface. An Arab physicist, Ibn al-Haytham, published his Book of Optics in 1021 AD.