A quick guide to getting more

1. Lens sizes
Depth of Field

2.  Camera lenses come in different sizes:

3.  The longer the lens the more it enlarges the object
being photographed

4.  Lens are measured in mm…
 50mm is roughly the same as what we see with
the human eye:

5.  Less than 50mm (typically 24-30mm) gives wide
angles:

6.  And more than 50mm (typically 70mm+) zooms in
on a subject:

7.  A zoom lens is a jack of all trades lens that can
change its length from, say, 30mm to 70mm:

8.  Many digital cameras do not have a CCD
sensor that is as big as a 35mm film frame so
some cropping occurs
GEEKGEEK
ALERT!ALERT!

10.  Depth of Field (DOF) refers to how much of a
photo is in focus
 Suppose you have focused on a person you want
to photo:

11.  The DOF is the distance you could move the
object towards or away from the camera without
having to re-focus:

12.  Everything outside of this zone will be blurred and
out of focus

13. >>> DEMO <<<
>>>DOF with zoom lens<<<

14.  There are three (four counting Photoshop) ways to
create shallow Depth of Field:
1. Use a long (70mm+) lens or a zoom
2. Set a smaller aperture setting (f2.8 / f4)
3. Put a Neutral Density filter on your lens

15.  There are various setting on an SLR camera:
 ISO
 Shutter Speed
 Aperture
 They all adjust different aspects of your photo…

16.  Aperture adjusts the Depth of Field by changing
the size of the hole that light travels through to get
to your film/CCD:

17.  Basically, the smaller you set the f number to, the
smaller your Depth of Field:

19.  Changing the aperture means changing the
shutter speed to compensate (more next week),
for now…
 Set your camera to aperture priority mode (usually
marked ‘A’ or ‘Av’on the control dial)

20. Narrow DOF
Wide DOF

21. >>> TASK <<<
 Put an a few objects on along a table
 Step back as far as you can and zoom in to create DOF
 Then get closer and take two identical photos – one on f2.8 and one
on f16
 If you don’t have these setting on your camera try using Macro
mode and getting really in close…
 …and/or take some photos that you can add DOF to later using
Photoshop

22.  On a bright summer’s day you will have to set
your aperture to a high number (f11 / f16) to avoid
over exposure…
 So setting a small f-number to
get a small Depth of Field
will not work
 The solution is to put a
Neutral Density filter on your
camera…

23.  Using an ND filter is a bit like putting sunglasses
on your camera

24.  What this means is that you can open the aperture
a bit more and get more Depth of Field
 ND filters do not effect the colour, only the amount
of light reaching the film/CCD

25.  And, of course, Depth of Field can be faked using
Photoshop selections and a blur filter:

26.  >>> END <<<