Film Format & Film Speed

By: Amit Chawla

Difference

Film Format refers to the size of the film and with it the quality of photograph that is taken with a particular type of film.

This should not be confused with film speed. Film speed describes a film's threshold

sensitivity to light. It is related to the size of the Grains in the film.

Film Formats

Films are available in various sizes and ratios ranging from

– Large Format

– Medium Format

– Small / Standard Format

Various Film Formats

4” x 5”

6 x 7 cm

6 x 4.5 cm

6 x 6 cm

35 mm16mm

Standard Large Medium

Available Less available Less available

Affordable Expensive Expensive

developed widely Spl film developing Requires spl film

35 to 36 shots per roll 1 shot. Less shots per Roll (12-15 )

Used by both amateurs and professionals

used by professionals used by professionals

Allows manipulation but graininess

comes in

doesn’t allow manipulation

allows manipulation

light equipment heavy equipment heavy and bulky equipment

Why different formats?

Larger formats mean finer quality, bigger enlargements and also better camera movements.

Small formats mean smaller camera which are faster to use and also portable. Also smaller formats give a greater depth of field than pictures on larger formats (keeping lens and f-number constant)

Small cameras as well as small format films are cheaper than medium and large formats.

MOST COMMON FORMAT

135 (ISO 1007) is a film format for still photography, also widely referred to as "35 mm". Introduced in its modern form in 1934 it quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film format.

What is film speed ?

Film speed describes a film's threshold sensitivity to light.

The international standard for rating film speed is the ISO scale which combines both the ASA speed and the DIN speed in the format

What does grain size do ?

Grain size refers to the size of the silver crystals in the emulsion. The smaller the crystals, the finer the detail in the photo and the slower the film.

The lower the number (e.g.. 100), The less sensitive to light your film is, the higher the number (ISO 3200), the more sensitive to light your film is.

100 1600

Common film speeds

Common film speeds include ISO 25, 50, 64, 100, 160, 200, 400, 800, 1600, & 3200.

Consumer print films are usually in the ISO 25 to ISO 800 range

ISO 25 film is very "slow", as it requires much more exposure for usable image than "fast" ISO 800 film.

Films of ISO 800 and greater are thus better suited to low-light situations and action shots (where the short exposure time limits the total light received)

DIFFERENCE

SLOW FILM finer grain and better

color. Slow film resolves finer

resolution than fast film.

It requires longer exposure times, so you might need a tripod

At some point, it becomes wasteful to use slow film if u don’t enlarge

FAST FILM Not as fine

Less resolution

Short exposure . Good for motion and less light

Shows same product at small enlargement

An example

EXTRA INFO

Film speed is related to the size of the grains of silver halide in the emulsion, since larger grains give film a greater sensitivity to light.

Fine-grain stock, such as portrait film, is "slow", meaning that the amount of light used to expose it must be high or the shutter must be open longer.

Fast films, used for shooting in poor light or for shooting fast motion, produce a grainier image.

Each grain of silver halide develops in an all-or-nothing way into dark silver or nothing.