The evolution of black and white film
After Silver Gelatin Bromide, a procedure developed by Richard Leach Maddox in 1871 to replace collodion, which made emulsions faster and faster, George Eastman launched in 1888 the first camera to use negative paper roll to record images: the Kodak 100 vista. It allowed the registration of 100 circular images – of low quality – that, once shot, were sent together with the camera to be developed. Once the process was completed, the camera was returned to its owner with a new paper film. This system led to experimentation with other materials, and the following year the paper was replaced by others that are still in use today: celluloid and its gelatin emulsion.
BROWNIE Nº 2 AND THE 120 MM
The No. 2 Brownie camera manufactured by Kodak between 1901 and 1935 was the first to use the 120 mm reel. The 120 mm film is wrapped around a reel and protected from light by a paper strip. It can store approximately 12 photographs and provides us with images of formats such as 6x6, 6x7, 6x9, 6x12 cm and 6x17 among others.
Barnack and 35mm
Oskar Barnack, an engineer at the Leitz factory, proposed reducing the size of the cameras in order to be able to take pictures outside without his breathing problem being an impediment. This way, he built the first "small format" camera and adapted the 35mm film that until then had been used exclusively in cinema, for photography. Thus, the Ur-Leica was born in 1913, but it was not until 1924 when the improvement of the film’s quality led to the camera’s mass production. This camera was a real revolution, especially for graphic reporters.
Within the black and white we would stand out:
1. Slow films: their ISO values are between 25 and 50. Silver halides are small. Widely used for detail-photography. It needs long exposure times.
2. Medium films: their values go from 100 to 200 ISO. They have great sharpness. Their versatility has made them one of the most demanded films in the market.
3. Fast films: between 400 and 1000 ISO. They allow to work in very fast times. The grain is more extensive.
4. Very fast films: from 1000 ISO. Used especially when there is very little light in the scene.
5. Panchromatic films: high and medium sensitivity. Produces a completely realistic image.
6. Orthochromatic film: being sensitive to blue and green light, they can be processed with red light. Its main characteristic is that due to the sensitivity it has with the color blue, these, are shown lighter, while the reds appear darker.