Secret of 140K MP Daguerrotype
I read an article http://www.wired.com/magazine/2010/0...type_panorama/
about a newly started to be restored Daguerrotypes at GEH. They report the plates have an sensivity of 140000 Megapixel
. They write if images enlarged to 50 meters , it would not lose any detail. Grain size 150 to 800 nanometers.
For whom who have no time to check the article , I want to add GEH could not recognize the detail count with loupe or macro lens but stereo microscope. Article puts detailed analysis.
I want to ask ;
- Are our films better today ? Can ULF cameras surpass that quality ?
- What is the particle size of not exposed plate and modern film ?
- Do we use bromide, chlorine and iodine at our emulsions today ? Who uses them together at their modern films ?
When Petzval lenses were introduced in 1841, with a larger effective aperture and the plate was sensitized not only with iodine but also with bromine and chlorine and forming light sensitive crystals of silver iodide, silver bromide and/or silver chloride that are more light sensitive than silver iodide .
Exposure times were later reduced by sensitizing the plate with other silver halides: silver bromide and silver chloride, and by replacing the Chevalier lenses with much larger, faster lenses designed by Joseph Petzval.
- What is the role of Mercury ?
The image in a daguerreotype is often described as being formed by the amalgam, or alloy, of mercury and silver because mercury vapor from a pool of heated mercury is used to develop the plate; but using the Becquerel process (using a red filter and two-and-a-half stops extra exposure) daguerreotypes can be produced without mercury, and chemical analysis shows that there is no mercury in the final image with the Bequerel process. This leads to questioning the theory that the image is formed of amalgam with mercury development.
- How some 3D objects looks like jump out of the plate ? Is it because single element
or petzval lens aberrations or the chemistry or...?
From wikipedia article !
The polished silver surface of a daguerreotype gives a feeling of presence where the image appears to be floating in space.How is that ?