Assignment 2

1. Calculate the aperture diameter for each lens aperture: 

The smallest focal length of my first zoom lens is 18mm:

Focal Length	Aperture Size	Aperture Dimension
18mm	4	4.5
18mm	5.6	3
18mm	8	2.25
18mm	11	1.63
18mm	16	1.125
18mm	22	0.81
18mm	32	0.56

The smallest focal length of my second lens is 75mm:

Focal Length	Aperture Size	Aperture Dimension
75mm	4	18.75
75mm	5.6	13.39
75mm	8	9.37
75mm	11	6.81
75mm	16	4.68
75mm	22	3.41
75mm	32	2.34

  

2. If f4 on a 50mm lens has an aperture diameter of 12.5mm, what would the diameter of f4 on a 400mm lens be?

400 = 100mm

   4

Therefore the diameter of a 400mm lens with 4f-stop would be 100mm.

3. Identify where your depth of field preview button is located-

The Depth of Field preview button on my Canon 550D is located just below the button used to release lenses. This Button enables you to have a preview of the depth of field.   

4. Research the term ‘Hyperfocal Distance’ and describe how you would use it-

Hyperfocal Distance is the distance at which photos can be brought into focus, it maximises your depth of field. If you focus a camera at the Hyperfocal distance everything from the foreground to infinity will be sharp and in focus, which is why landscape photographers commonly use Hyperfocal focusing. 

You would use hyperfocal focusing if you had a rock in the foreground that you wanted to focus on and you also had for example the ocean in the background that you wanted to also be in focus. Using Hyperfocal focusing enables you to have an overall sharper image, which is ideal for printing.  

Examples

This photo was taken with normal infinity focusing. As you can see the ice in the front right hand corner is blurred.    

This photo was taken with Hyperfocal focusing, as you can see the ice in the front right hand corner is not blurred and instead it is sharp and in focus.