Grain, Gauge & Speed

Probably one of the most important developments in the history of word cinema production was the development of first film stocks; it gave the film makers the freedom to photograph scenes which were once considered impossible.

Earlier without the use of huge, expensive arc lights film making was considered impossible, but with the introduction of film stocks film makers could use the available light to shoot, at night or indoor.  First came the color stock and then the black & white, which gave the film almost the same sensitivity that our eyes have. The exposure speed of a film stock is closely linked with its definition or grain, and varies inversely. Faster films are grainer; slower films give sharper, fine grain images.

A standard frame of 35mm film has an area slightly more than half a square inch. If it is projected on to a screen which is 40 feet wide, it has to fill an area that is 350000 times larger than itself – a prodigious task. And in case of a 16 mm film the magnification is 1400000 times more. The graininess of the film stock which is unnoticeable if the enlarged range is kept with 8×10 inch prints. Then the question rises how a 35 mm or a 16 mm film will be projected on to a 40 feet wide screen, sharp and clear. The distance between the image and the viewer comes into play at this point of time. From the back row of a very large theatre with a small screen, the image of a 35mm movie might appear in the same perspective as in an 8×10 print held one foot in front of the observer. In that case the grain would appear to be more or less equivalent.

35mm film stock has been there for a number of years now, most suitable for the amateur filmmakers, where as the 16mm stock has been useful for the television work. The ‘super 16’ format developed in the early 1970s was measurably having a little more area in the frame and the definition of the image. But whatever problems of definition and precision exits in 35mm will be multiplied by a factor of 4 in 16mm and a factor of 16 in a 8mm film stock. But by the same logic, a grater or wider film stock (say 70mm) will greatly ameliorate those problems. Hence 70mm film stocks are valuable for productions that need a feeling of panoramic details and power on a large screen.

Lastly, regarding the cost, 16mm stock is two to four times cheaper than 35mm stocks. But the most important thing to notice is the gauge of a film stock, which is a double variable. As because with wide screen processes the gauge in which the film is shot need not to be the one or same gauge in which it is distributed. For the most part, the gauge of the projected print is important in accordance with the size of the screen it must fill, while the gauge of the negative camera original will affect the clarity of the film throughout the several processes it will undergo.