Project 1: The distorting lens – Exercise 2.5

Exercise 2.5
Find a subject in front of a background with depth. Take a close viewpoint and zoom
in; you’ll need to be aware of the minimum focusing distance of your lens. Focus on
the subject and take a single shot. Then, without changing the focal length, set the
focus to infinity and take a second shot.

The closer you are to the subject, the shallower the depth of field; the further from
the subject, the deeper the depth of field. That’s why macro shots taken from very
close viewpoints have extremely shallow depth of field, and if you set the focus at
infinity everything beyond a certain distance will be in focus.

As you review the two shots, how does the point of focus structure the composition?
With a shallow depth of field the point of focus naturally draws the eye, which goes
first of all to the part of the image that’s sharp. It generally feels more comfortable if
the point of focus is in the foreground, although there’s nothing wrong with placing
the point of focus in the background.


These two images were taken at the end of my road. The first focusing on the top nodule of a post box. This sharply focuses on the foreground and throws the background out of focus. The Second focusing on infinity puts the background in focus and throws the foreground out of focus.

They were all taken with:

  • Aperture priority
  • ISO 100
  • f/5.0
  • Fujifilm X30 equivalent 35mm focal length of:
    • 56mm
road-short-focus

Post box and up the road – Short focus

road-long-focus

Post box and up the road – Long focus

I can see that playing with the point of focus will effect the depth of field. This will be a useful technique to limit or restrict attention to elements within the image.

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Project 1: The distorting lens – Exercise 2.7

Exercise 2.7
Use a combination of small apertures and wide lens to take a number of photographs
exploring deep depth of field. Because of the small apertures you’ll be working with
slow shutter speeds and may need to use a tripod or rest the camera on a stable
surface to prevent ‘camera shake’ at low ISOs. Add one or two unedited sequences,
together with relevant shooting data and an indication of your selects, to your
learning log.

Achieving deep depth of field might appear easy compared to the difficulties of
managing shallow depth of field. We’re surrounded by images made with devices
rather than cameras whose short focal lengths and small sensors make it hard
to achieve anything other than deep depth of field. The trick is to include close
foreground elements in focus for an effective deep depth of field image. Foreground
detail also helps to balance the frame, which can easily appear empty in wide shots,
especially in the lower half. When successful, a close viewpoint together with the
dynamic perspective of a wide-angle lens gives the viewer the feeling that they’re
almost inside the scene.


The following images using the above settings all taken using a tripod. The deep depth of field creates an acceptable level of focus from the front of the image to the back of the image.

The foreground elements coupled with the receding elements provide layers giving a sense of depth and 3D quality.

Project 1: The distorting lens – Exercise 2.6

Exercise 2.6
Use a combination of wide apertures, long focal lengths and close viewpoints to
take a number of photographs with shallow depth of field. (Remember that smaller f
numbers mean wider apertures.) Try to compose the out-of-focus parts of the picture
together with the main subject. Add one or two unedited sequences, together with
relevant shooting data and an indication of your selects, to your learning log.

Wide apertures create shallow depth of field, especially when combined with a long
focal length and a close viewpoint. In human vision the eye registers out-of-focus
areas as vague or indistinct – we can’t look directly at the blur. But in a photograph,
areas of soft focus can form a large part of the image surface so they need to be
handled with just as much care as the main subject.

Don’t forget that the camera’s viewfinder image is obtained at maximum aperture for
maximum brightness and therefore at the shallowest depth of field. Use the depth of
field preview button to see the actual depth of field at any particular aperture. (This
is especially useful in film cameras where you don’t have the benefit of reviewing a
shot immediately after you’ve taken it). It’s surprising to see the effect that a single f
stop can have on the appearance of an image.


This combination of settings provides a very pleasant image with soft dreamy blurred background that really makes the focused object stand out as can be seen from the images below caused by a relatively narrow depth of field.

As can be seen this ‘bokeh’ effect is particularly pleasing with portraits, but it is just as effective with making all objects stand out from their backgrounds.

Project 1: The distorting lens – Exercise 2.4

Exercise 2.4
Find a location with good light for a portrait shot. Place your subject some distance in
front of a simple background and select a wide aperture together with a moderately
long focal length such as 100mm on a 35mm full-frame camera (about 65mm on a
cropped-frame camera). Take a viewpoint about one and a half metres from your
subject, allowing you to compose a headshot comfortably within the frame. Focus
on the eyes and take the shot.

Longer focal lengths appear to compress space, giving a shallower depth of
acceptable sharpness, which is known as depth of field. This makes a short or medium
telephoto lens perfect for portraiture: the slight compression of the features appears
attractive while the shallow depth of field adds intensity to the eyes and ‘lifts’ the
subject from the background.


These settings provide a much more flattering look to portraits especially taken at the same level. The 3 images below show this to quite good effect I feel.

The look is defiantly more aesthetically appealing.

Project 1: The distorting lens – Exercise 2.3

Exercise 2.3
Choose a subject in front of a background with depth. Select your shortest focal
length and take a close low viewpoint, below your subject. Find a natural point of
focus and take the shot.
You’ll see that a very wide lens together with a close viewpoint creates extreme
perspective distortion. Gently receding lines become extreme diagonals and rounded
forms bulge towards the camera. Space appears to expand. The low viewpoint adds
a sense of monumentality, making the subject seem larger than it is, and tilting
the camera adds to the effect as vertical lines dramatically converge. Not the ideal
combination for a portrait shot!


The shots below were taken with my Fuji X30 at its shortest focal length of 28mm. This is wide but not extremely, so the shots while not ideal show some distortion. Unfortunately there were not any high buildings or objects so there is not much in the high background to demonstrate the distortion effect. But the low-lying object do show distortion and parallel lines demonstrate convergence. This does give an impression of grandeur and largesse. But not (as mentioned in the brief) very flatering for portraiture. Though this effect could be used to great effect to make someone look powerful or important if used with care, judgement and good lighting.

Project 1: The distorting lens – Exercise 2.2

Exercise 2.2
Select your longest focal length and compose a portrait shot fairly tightly within the
frame in front of a background with depth. Take one photograph. Then walk towards
your subject while zooming out to your shortest focal length. Take care to frame the
subject in precisely the same way in the viewfinder and take a second shot. Compare
the two images and make notes in your learning log.

As you page between the two shots it can be shocking to see completely new
elements crash into the background of the second shot while the subject appears
to remain the same. This exercise clearly shows how focal length combined with
viewpoint affects perspective distortion. Perspective distortion is actually a normal
effect of viewing an object, for example where parallel train tracks appear to meet
at the horizon. A ‘standard lens’ – traditionally a 50mm fixed focal length lens for
a full-frame camera (about 33mm in a cropped-frame camera) – approximates the
perspective distortion of human vision (not the angle of view, which is much wider).
A standard lens is therefore the lens of choice for ‘straight’ photography, which aims
to make an accurate record of the visual world.


Below are 2 shots I took near the South Bank Friday lunchtime with my Fujifilm X30 compact camera. The pair of images are framed on the sign. They were all taken with:

  • Aperture priority
  • ISO 100
  • f/5.0
  • Fujifilm X30 equivalent 35mm focal lengths of:
    • 112mm
    • 28mm
focal-length-112mm

Tenison Way – Focal length 112mm

focal-length-28mm

Tenison Way – Focal length 28mm

The difference in the view between these two images is striking considering the fact that the subject occupies the same space in the frame.

Project 1: The distorting lens – Exercise 2.1

Exercise 2.1
Find a scene that has depth. From a fixed position, take a sequence of five or six
shots at different focal lengths without changing your viewpoint. (You might like to
use the specific focal lengths indicated on the lens barrel.)

As you page through the shots on the preview screen it almost feels as though you’re
moving through the scene. So the ability to change focal lengths has an obvious use:
rather than physically moving towards or away from your subject, the lens can do
it for you. The other immediate difference between the shots is the ‘angle of view’,
which also depends on the sensor size of your camera. Use the sequence to try to
get a feeling for how the angle of view corresponds to the different focal lengths
for your particular camera and lens combination. Which shot in the sequence feels
closest to the angle of view of your normal vision?

Does zooming in from a fixed viewpoint change the appearance of things? If you enlarge and compare individual elements within the first and last shots, you can see that their ‘perspective geometry’ is exactly the same. To change the way things actually look, a change in focal length needs to be combined with a change in viewpoint.


Below is a sequence of 5 shots I took on the South Bank Friday lunchtime with my Fujifilm X30 compact camera. The sequence does give the appearance of travelling through the image. They were all taken with:

  • Aperture priority
  • ISO 100
  • f/5.0
  • Fujifilm X30 equivalent 35mm focal lengths of:
    • 28mm
    • 35mm
    • 50mm
    • 85mm
    • 112mm

Of all the images taken, the image taken at a focal length of 50mm appear to me the closest to normal vision.

focal-length-28mm

South Bank – Focal length 28mm

focal-length-35mm

South Bank – Focal length 35mm

focal-length-50mm

South Bank – Focal length 50mm

focal-length-85mm

South Bank – Focal length 85mm

focal-length-112mm

South Bank – Focal length 112mm