Digital Camera Formats

As a technical element, the camera takes the main place in the process of creating images. With whatever kind of camera nowadays, we can create excellent pictures, as long as we know what we have and above all it's limitations . Many amateur only have a partial knowledge of there own camera but don't hesitate at blaming it for the unsuccessful pictures. A perfect comprehension of our particular camera and it's handling, not as an "autonomous" and hard to control being, but as a tool that follows set functioning rules. All we have to do with the camera: frame, focus, select the aperture and speed, depends on the characteristics of the scene, the performance of the film and what we want to do . The desire to make good photographs requires that sooner or later we understand the machine. After a certain amount of experience you can reach this understanding and the camera becomes an observation tool, a book were we carry images. We know it's functions are principally the exposure and focus. Besides there are also other characteristics which we are going to examine, and that define the different kinds of cameras, there operation and applications.

The format, or size of the film, expresses the amount of film used to describe the scene. The quality of the image will be greater, the larger the format is, because every part of the scene corresponds to a larger surface of the film to describe it. Besides the surface of the film, an important aspect of the format is the relationship between the height and width, as in the movies it can have different values. The larger the format, the larger and less manageable the camera is. The main formats, from smallest to greatest are the following:

Small Camera Format

• APS ( Advanced Photo System ). The Advanced Photo System offers the possibility to choose between three formats when using the same roll of film. A selector on the camera lets us choose a format in which the sides of the frame have a relation of 1:1.4 (format C); another wider one with a relation of 1:1.8 (format H); and a panoramic in which the sides have a relation of 1:3 (format P). The film has a magnetic band were the information of the exposure, flash and other instructions the photographer wanted to give the lab (information exchange system IX). When we take the roll to be developed, the copy machine reads the stored information and determines the size of photographic paper needed for the format and the corrections and adjustments necessary for each picture. After developing, the film is permanently stored in the roll and has an identification code. The laboratory includes an index card with miniature images for later reference. Thanks to recording the data, some cameras offer the possibility of removing from the camera a started roll and change it for another one (for example, of another sensitivity) an reintroduce it whenever we want. On the roll there is information to know if it's virgin, started, finished or developed. The surface of an ASP negative varies with the format. Format H is larger: 30.2 x 16.7 mm. Format C is obtained by eliminating to vertical strips on the sides; format P is obtained eliminating two horizontal strips. Therefore format P doesn't mean the angle covered in relationship with format H, it's simply a way of obtaining a longer print by sacrificing the top and bottom of the frame.

• 35mm or universal step . On perforated 35 mm wide (as in the cinema), the camera produces images that are 24 mm high and 366 mm wide (1:1.5 relation). It is the most widely used format and were the most advances in automatism, lens systems and accessories is made. Likewise, the variety and availability of film is greater than any other format. With a 35 mm you have access to a greater field of possibilities.

Medium Digital Camera Format

Medium format cameras use un perforated, 6 cm wide film. The film is attached to a strip of dark paper and wrapped around a core (there is no rigid encasing). The most widely used medium formats are:

6cm x 4.5cm ("4½ x 6", relation 1:1.33)
6cm x 6cm ("6 x "6, relation 1:1)
6cm x 7cm ("6 x 7", relation 1:1.16)
6cm x 9cm ("6 x 9", relation 1:1.5)

The increase of quality from a 35 mm format is remarkable because, for example, a 6 x 6 film is approximately four times larger. A medium format camera is a professional tool, specially if it is being used outside a studio. As in 35 mm, there are medium format cameras with a complete lens system, plate holders for different formats or types of film and accessories. A medium format with a interchangeable plate holder can be converted to a digital camera by placing a back with a sensor were the film usually goes.

Large Digital Camera Format

Large format cameras use individual sheets of film, also called "plates". Each sheet is placed in a flat, lightproof plate holder with a small curtain which is removed when the plate is inside the camera and the shutter closed. Large format cameras used nowadays are called "studio cameras", which are handled on a tripod and generally have the same characteristics that our ancestors used (they were made of wood). It's design is very simple. On a rod the support for the lens and the support for the plates can slide independently. Both are joined by dark flexible accordion. The lens and the focal screen don't only move closer and farther from each other (to focus), they also can also move horizontally and vertically on there axis. These movements add possibilities, allowing images that are inaccessible to other cameras. The most used formats are:

9 cm x 12cm (relation 1:1.33)
4 inches x 5 inches (10.16 x 12.7 cm, ,relation 1:1.25).
13cm x 18 cm (relation 1:1.38)
20cm x 25 cm (relation 1:1.25)

Any of these provides a far superior image quality than medium formats. It is used to make photographs of the best professional quality, or for those which are going to be greatly enlarged: publicity, billboards, posters, murals, etc. As well as with medium format the cameras can be used with a digital back.