Monday, February 25, 2008

Photographic Paper

Until the advent of digital photographic processes, the individual meaning of photographic.

Paper was paper covered with light-sensitive chemicals. So-called photo papers of today are frequently specially coated papers for use in inkjet or laser printers to make digital prints. This article center of attention on traditional photographic papers. Photographic paper may be showing to light in a controlled manner either by placing a negative in make contact with the paper directly (contact printing) or by using an enlarger (enlarging) in order to create a latent image. Photographic papers are subsequently developed using wet chemicals to generate a visible image.

Tuesday, February 19, 2008

Photographic Printing

Photographic printing is the method of producing a final image for viewing, usually on sensitized paper from a previously prepared photographic negative.

The procedure consists of three major steps, performed in a photographic darkroom or within an automated photo printing machine:

1. Exposure of the picture onto the sensitized paper using a contact printer or enlarger.

2. Processing of the latent image through a more than one step chemical immersion process.

1. Development of the uncovered image.

2. Optionally Stopping improvement by neutralizing, diluting or removing developing agent.

3. Fixing the final print by dissolving remaining unexposed/undeveloped light-sensitive liquid.

4. Washing thoroughly to eliminate chemicals used in processing, protecting the finished print from fading and decay.

3. If finished on glossy paper, ferrotyping to enhance the reflective gloss.

4. Optional Toning of the print through extra chemical processes.

5. Texturing and drying of the finishing print.

Monday, February 11, 2008

Inkless Printers

Inkless printers use paper with colorless dye crystals embedded connecting the two outer layers of the paper. When the printer is twisted on, heat from the drum causes the crystals to colorize at different rates and become visible. The technology was worked on by Zink Imaging and is now accessible (2007). Because of the way it prints, the printer can be as little as a business card, the images are waterproof, and in fact, one product slated for release by Zink Imaging is a digital camera with a printer built into it. Xerox is also working on an inkless printer which will use a extraordinary reusable paper coated with a few micrometres of UV light sensitive chemicals. The printer will use a particular UV light bar which will be able to write and erase the paper. As of early 2007 this technology is at a halt in development and the text on the printed pages can only last between 16-24 hours before fading.

Wednesday, February 06, 2008

The real facts about Earth

The Earth's surface is exceptionally young. In the relatively short (by astronomical standards) time of 500,000,000 years or so erosion and tectonic processes destroy and restructure most of the Earth's surface and thus eliminate almost all traces of earlier geologic surface history (such as impact craters). Thus the very before time on history of the Earth has mostly been erased. The Earth is 4.5 to 4.6 billion years old, but the oldest recognized rocks are about 4 billion years aged and rocks older than 3 billion years are rare. The oldest fossils of presented organisms are less than 3.9 billion years old. There is no evidence of the critical period when life was first getting in progress.

The Earth's environment is 77% nitrogen, 21% oxygen, with draws of argon, carbon dioxide and water. There was perhaps a very much bigger amount of carbon dioxide in the Earth's atmosphere when the Earth was first created, but it has since been nearly all incorporated into carbonate rocks and to a smaller extent dissolved into the oceans and consumed by living plants. Plate tectonics and biological processes now keep a frequent flow of carbon dioxide from the atmosphere to these various "sinks" and back over again. The little amount of carbon dioxide occupant in the atmosphere at any time is very important to the maintenance of the Earth's surface temperature through the greenhouse effect. The greenhouse consequence raises the average surface temperature regarding 35 degrees C above what it would if not be (from a frigid -21 C to a comfortable +14 C); without it the oceans would freeze and life as we know it would be impossible.