Film format refers to the size of the film, which determines image quality and size of possible prints. Film speed describes a film's sensitivity to light, related to grain size - larger grains provide higher sensitivity but lower resolution. Common film formats are large format, medium format, and small/35mm format. Film speeds range from ISO 25 to 3200, with slower films having finer grain but requiring more light, and faster films being suited to low light situations.

1. Film Format & Film Speed
By: Amit Chawla

2. 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.

3. Film Formats
 Films are available in various sizes and ratios
ranging from
– Large Format
– Medium Format
– Small / Standard Format

4. Various Film Formats
4” x 5”
6 x 7 cm
6 x 6 cm
6 x 4.5
35 mm
cm 16
mm

5. 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 used by professionals used by professionals
amateurs and
professionals
Allows manipulation doesn’t allow allows manipulation
but graininess manipulation
comes in
light equipment heavy equipment heavy and bulky
equipment

6. 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.

7. 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.

8. 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

9. 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.

10. 100 1600

11. 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)

12. DIFFERENCE
SLOW FILM FAST FILM
 finer grain and better  Not as fine
color.
 Slow film resolves finer  Less resolution
resolution than fast film.
 It requires longer exposure  Short exposure . Good for
times, so you might need a
motion and less light
tripod
 At some point, it becomes
wasteful to use slow film if  Shows same product at small
u don’t enlarge enlargement

13. An example

14. 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.