Pixiq

It is astonishing that after 175 years the daguerreotype still beats both film and digital photography in its ability to capture image detail. As an example, take a look at the “Cincinnati Panorama of 1848.” It shows a two mile section of the city waterfront taken from across the Ohio River. The panorama is made up of eight relatively small 6.5 x 8.5 inch silver plates, yet they each contain an amazing amount of detail. With a microscope you can read store signs and count the number of bricks in a wall, as you shown in the photo above.That’s far better rendition of detail than even the best digital camera is capable of capturing.

How is this possible? For the answer we can compare how the different processes capture images. Film photography utilizes light sensitive silver crystals suspended in an emulsion to do the job. Light reaches the crystals and turns them into bits of silver. Particularly if you have taken photos with fast films you’ve seen the clumps of exposed silver called “grain.” Grain is the limiting factor in recording detail.

Digital photographs, on the other hand, are made up of millions of discrete bits of information from the sensor pixels. The pixel, like grain, limit the amount of detail you can get in an image. If you enlarge a digital image file to just 4x its normal size (800%), the image becomes millions of tiny colored squares. Daguerreotype images have been examined with microscopes and even at 30x magnification, the images are sharp and crisp.

The resolution of a digital photo is limited by these pixel squares. While the 70 gigabyte photo of Budapest, that I reported on in my previous PIXIQ post, contains almost the amount of detail of the Cincinnati panorama, it was made by stitching together thousands of individual digital images. The daguerreotypists achieved this level of detail in every single one of their exposures.

How does this happen? Daguerreotypes are copper plates that were clad in pure silver by a process called cold-rolled cladding. Silver foil was heated and rolled in contact with a copper plate producing a surface that was .999 pure silver. The plate was then “sensitized” by placing it in the fumes of iodine vapors which resulted in the formation of silver iodide on the plate's surface. The image is then the result of the interaction of photons of light with the sensitived surface.

The “development” process for daguerreotypes was dangerous and often fatal. After the plate was exposed in the camera, it was developed in mercury fumes rising from a pool of heated mercury. This made the image an amalgam, an alloy, of mercury and silver. Unfortunately, mercury fumes are deadly and the “dark rooms” and 'dark tents' of the mid-1840s were not ventilated. This resulted in death or madness for many would be 19th century photographers.

Because the processed image is an amalgam there is no “grain.” The image is literally stored on a molecular level and that’s why the 163 year old Cincinnati Panorama daguerreotype of 1848 has such incredible detail.

One day perhaps our digital cameras will be able to do the same.

For a closer look at the astonishing Cincinnati Panorama of 1848 go to the Herald's website and click on the image in the story and you'll get to the really big picture.  

http://www.thecincinnatiherald.com/news/2011-05-21/News/The_Cincinnati_Riverfront_Panorama_of_1848_A_Windo.html