- “photos” + “graphos”

from the Greek = “light writing”

-  Writing with light

 - Drawing with light

- Painting with light

the minimum amount of light required to record

adequate shadow and highlight detail

should (normally) resemble the brightness

of the original scene

Exposure is the amount of light collected by the film or digital sensor

in your camera during a single picture.

A light meter measures how much light there is.

It tells us how we should set our camera to ensure that the correct

amount of light strikes the sensor

Depending on the Mode it will tell us - 

ISO Mode - What our shutter speed needs to be                        (how long the aperture needs to be open for)                          

                and how large the aperture needs to be (f-stop)

Aperture Mode - What our shutter speed needs to                             be (how long the aperture needs to be open for)

                 and what our ISO needs to be

               (the amount of light to let in)

Shutter Speed Mode - What our ISO needs to be                                      (the amount of light to let in)

                                and what our aperture needs           to be (f-stop)

-measures the strength of the light falling on the

subject

-the meter is “aimed” towards the camera or light

source

-light is metered as it bounces off the subject

-the meter is “aimed” towards the subject.

18%

Your camera is calibrated to this.

A typical grey card.

It is the amount of grey reflected back when light falls on it's surface.

Represents the middle between the blackest recordable black and the whitest recordable white.

Approximately 3.5 stops from black and 3.5 stops from white.

Proper exposure is lining up the bar to hightlight under

the reversed triangle.

It show’s how many stops you can be over or under

exposed.

It’s a good scale to use, because when you want to over

ride your light meter’s measurements by a certain

amount of light, you know how much you can dial in or

out.

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1. Sensor “Speed” or sensitivity - ISO (ASA/DIN)

2. Aperture - f/stop

3. Time - shutter speed

How sensitive to light your film or

sensor is.

Opening that

allows

how much light gets into your camera and

onto your film/sensor.

Controls the time, how

long the aperture will stay open to allow

light in.

ISO - Grain

Aperture - DoF (Depth of Field)

Shutter Speed - Blur

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100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600…

The higher the ISO setting (number), the MORE sensitive the image sensor or

film are to light. The “less” light is needed for an exposure.

Higher ISO settings are generally used in darker situations to get faster

shutter speeds (for example an indoor sports event when you want to freeze

the action in lower light)

Depending on how “fast” of an ISO you are using,

meaning a higher number, this will affect the final quality of your image.

A

higher ISO, ie: ISO 3200, will have larger visible “noise” or “grain”.

It’s a photographers term to describe

the amount of light ... or the exposure

value

- ISO 100 will record 1 stop less light

than ISO 200

    - a shutter speed of 1/125s will record 1

stop more light than 1/250s

    - an aperture of f5.6 will record one stop

less light than f4

An iris composed of thin, sliding, interlocking metal plates.

As you close the iris down to a smaller aperture, it stops more light from passing through to the image sensor.

The size of the aperture is measured in stops or

f-stops.

The higher the f-stop rating, the smaller the opening and the more light your aperture is “stopping”.

The smaller the number (larger the opening) the more light will illuminate your scene.

A lens set on f8 has a smaller

aperture than a lens set on f4.

In other words, f8 stops more

light than f4.

1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64

The common factor is the root of 2

between each stop (approx. 1.4)

F-Stops double at every other full stop in

either direction

A histogram displays all the tones in an image.

It can show if an image has clipped highlights or shadows.

The light range often looks like a mountain peak. The exposure is correct as neither the shadows nor highlights are clipped.

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The majority of the peaks of the histogram are on the left (shadows) side. This means there is lost data that can not be retrieved. 

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The majority of the peaks are on the right side (highlights) of the histogram. This means there are clipped highlights and lost data.

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The relationship between the intensity of the

light and duration of the exposure that result

in identical exposure.

In other words, when an adjustment is made in your exposure settings, the same exposure can be achieved by changing one of the other exposure settings the opposite amount... i.e.

f-8 @ 1/30th

is the same as

f-5.6 @ 1/60th

[image]

ISO 100, f-16 @ 1/60th

is the same as?

ISO 400, f-16 @ 1/250th

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Defined as the ratio of focal length to

lens diameter.

f# (or stop) = F(lens focal length)/D(lens diameter)

f8 always passes the same volume of light to the sensor no matter what lens or camera format.

Depth of field is the part of a scene that

appears acceptably sharp in a photograph.

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On a bright sunny day, with camera

aperture set to f16, the shutter speed

will be 1 over the ISO value

I.E.

f/16, ISO 200, 1/250 (250 is the closest)

The distance from the lens to the focal plane

when the lens is focused on infinity.

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It is where your sensor is located.

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It means your lens is focused so an infinitely-distant object would be sharp.

When an object is infinitely far away, the rays of light coming from it are, in theory, parallel. 

A lens set at infinity focus is set so that theoretical object would be in focus.

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The angle subtended at the lens by

the diagonal of the camera format when focused at

infinity.

(Subtend is the point where 2 lines meet to form an angle)

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The name given to electromagnetic radiation that can evoke a human visual response.

Visible wavelengths range from approx.

400nm(violet) to 700nm(red/infrared)

[image]

When the light waves are vibrating along a single plane.

How they look after entering a polarizing filter. 

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Random orientations of light. Not just vibrating up and

down, but also left to right, and everything in

between.

1. A clear blue sky and you camera is aimed at a 90 degree angle to the sun.

2. Reflective surfaces that are non-metallic such as water, glass and plastic. 

(Maximum effect when approximately 35 degrees to the glass)

3. Natural Crystals such as tourmaline.