First Powerpoint Summary Flashcards
What is the exposure triangle?
The exposure triangle is a common way of associating the three variables that determine the exposure of a photograph: aperture, shutter speed, and ISO. One must balance all three of these to achieve a desired result, an adjustment of one requiring adjustments of at least one of the others.
What is aperture?
Aperture is the unit of measurement that defines the size of the opening in the lens that can be adjusted to control the amount of light reaching the film or digital sensor.
How is appetite measured?
The size of the aperture is measured in F-stop.
REMEMBER: that the larger the number of the f stop the smaller the hole light is let in through. So F/22 is a small aperture (small hole), F/2 is a large aperture (large hole)
What is Depth of Field?
This is the range of proportion of your image which will be in relatively sharp focus.
DOF is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image.
What is a deep depth of field?
A deep depth of field means the whole image will be in focus. This would be used for taking landscapes for example.
A small aperture of f/22 would give a deep depth of field.
What is shallow depth of field?
When the aperture is large (ex. f/1.8) the area in front and behind the focus point is very slim or shallow. That means that objects right in front and right behind the plane of focus is already going out of focus. So only a small part of the image is focused.
This is often used for portraits and macro so only the subject that is photographed is in focus.
So, large DOF means?
Small aperture (big f/number) (f22)
So, shallow DOF means?
Large pasture (Small F/number) (f2.8)
What are the four things that can affect DOF?
There are four factors that affect depth of field: aperture, distance between you and the subject, focal length, and the sensor size. However, Aperture is the easiest way to control depth of field.
What is ISO?
ISO - International Standards Organisation
In Film (analogue photography) ISO is the sensitivity of the film.
In digital photography ISO is the sensitivity of the digital sensor.
How does ISO effect the image?
The lower the ISO number the less sensitive to light.
This effects the quality of the image is higher on a lower ISO.
A high ISO results in more ‘noise’ or loss of clarity in the image.
ISO is the optimum ISO on a digital camera. However, this is genuinely raised in proportion to the light conditions - lower light means higher ISO and in conjunction a change in shutter speed.
What is shutter speed?
This is the length of time that the shutter is open.
How is shutter speed calculated?
It is calculated in seconds and fractions of a second.
It is registered in numbers e.g 1/60 (one sixtieth of a second)
The higher the number the faster the shutter speed.
Why would shutter speed effect an image?
Shutter speed is what determines the length of time the shutter is open.
So for low light shooting conditions you would need a longer exposure (smaller numbers) so lower shutter speed. For example 1/15
If you wanted to capture action or freeze movement you would need a quick shutter speed (higher numbers) the argued optimum shutter speed being 1/125.
Anything below 1/60 leads to camera shake if you don’t use a tripod.
Things to remember about the exposure triangle:
All the elements on the triangle influence each other.
So,
If shutter speed is increased one stop, for example 1/125 to 1/150, you are letting half as much light in. So to compensate you will need to increase your aperture one stop (e.g f16 to f11) so making the hole the let’s in light larger.
Alternatively you could choose a more sensitive ISO - from 100 to 400
