The document provides an overview of key photography concepts including exposure, aperture, shutter speed, ISO, depth of field, focal length, and lens types. Exposure is determined by the amount of light reaching the image sensor, and can be controlled through aperture size and shutter speed settings. Aperture refers to the diameter of the lens opening while shutter speed is the duration that the camera's shutter is open. These settings, along with ISO, must be balanced to achieve proper exposure. Depth of field relates to the distance over which objects appear acceptably sharp, and lenses can be either prime lenses with a fixed focal length or zoom lenses with a variable focal length.

1. The Basics of Photography

2. Let there be light!
All photography is based on light
Exposure is the total amount
of light allowed to fall on the
film/image sensor

3. Too much light creates an over-bright
image with white spots: parts of the
image are Over-Exposed
Too little light creates an under-
bright image with black spots: parts
of the image are Under-Exposed

4. Exposure can be controlled through two lens
settings
• Aperture and
shutter speed
… and
Shutter
Speed

5. Aperture is the size of the gap light is let through
in the lens – similar to an eye’s pupil
- Aperture is measured in f-stop
numbers (e.g. f/2.8 or f/16)
The higher the f-stop, the smaller the
aperture

6. Shutter Speed denotes the exposure time, the effective
length of time a camera's shutter is open, The total
exposure is proportional to this exposure time, or duration
of light reaching the film or image sensor

7. To get a good exposure on manual mode, you have to make sure the
aperture and shutter speed balance each-other out correctly for the
sort of photo you want
On most SLRs you can switch on: Aperture Priority (you pick the
aperture, the camera picks the shutter speed), or -
Shutter Priority (you pick the shutter speed, the camera picks the
aperture – compacts usually have this too) -

8. ISO
ISO stands for
international standards
organization and can be
described as the
sensitivity of the sensor
to light. ISO is typically
measured in numbered
units starting from 50
going to 256,000. The
higher the number to
more sensitive the
sensor is to light. Most
DSLR cameras have a
ISO range from 100-
16000

9. Depth of field (DOF) is the distance between
the nearest and farthest objects in a scene
that appear acceptably sharp in an image.
Although aliens can precisely focus at only
one distance at a time, the decrease in
sharpness is gradual on each side of the
focused distance, so that within the DOF, the
unsharpness is imperceptible under normal
viewing conditions.
Depth of field (DOF)

12. Zoom or Prime There are two types of
lenses-prime and zoom. Prime lenses
have a fixed focal length and zoom
lenses have variable focal lengths. The
advantage of the zoom lens is its
versatility.
Zoom or Prime
Focal length, usually represented in
millimeters (mm), is the basic
description of a photographic lens.
It is not a measurement of the actual
length of a lens, but a calculation of
an optical distance from the point
where light rays converge to form a
sharp image of an object to the digital
sensor
Focal length

13. DSLR LENSES