Exercise 2.3 – wide-angle distortions

Center Parcs is an artificial environment with some interesting juxtapositions of familiar elements. The exercise calls for one example of distortions created by a low wide-angle viewpoint; I have selected two.

Technical details: Olympus E-30 with a wide-angle zoom, 9-18mm (18-36mm equivalent) used at the 9mm (18mm equivalent) end. Aperture-priority automatic exposure at f/5.6, ISO100. Shot in RAW, with some global Lightroom adjustments to tweak exposure and contrast.

OLYMPUS DIGITAL CAMERA

9mm (18mm equivalent) ISO100, 1/125 at f/5.6

OLYMPUS DIGITAL CAMERA

9mm (18mm equivalent) ISO100, 1/80 at f/5.6

The man-made elements have a vertical emphasis, as do the trees, which well illustrate the strong converging verticals. This lens has rectilinear correction, causing some ‘stretching’ toward the corners of the image.

Advertisements

Exercise 2.2 -focal length and viewpoint

Both images below are taken with an Olympus E-30 fitted with the kit standard zoom 14-42mm f/3.5-5.6. This is a Four-Thirds camera, so the crop factor is 2.0, giving an effective focal length range of 28-84mm. Aperture-priority automatic mode, 1/13sec at f/5.6, ISO1600.

Images were shot in RAW to enable correction of colour balance (mixed fluorescent sources) in post-production. Global alterations were made in Lightroom to correct colour balance (4250K, +28 magenta, -10 vibrance) and to tweak exposure and contrast. There are no local variations, although my natural inclination would have been to add about -10 post-crop vignetting (temptation manfully resisted).

OLYMPUS DIGITAL CAMERA

Focal length 42mm (84mm equivalent)

OLYMPUS DIGITAL CAMERA

Focal length 14mm (28mm equivalent)

The wider image changes the perspective of the coloured balls (serendipitous), brings in the scoreboard (intended) and a lot more of the high-level background (unintended and undesirable). The perspective distortion (due to the closer viewpoint) has also made my model’s right knee too prominent in the image.

Exercise 2.1 (supplementary) – a change of perspective?

An extract from the centre of a 9mm (18mm equivalent) view is compared with a 149mm (298mm equivalent) view.

The extract is distorted as a result of the rectilinear geometry of the lens. In keeping straight lines straight, there is a ‘stretching’ toward the corners. Ironically, a fisheye wide-angle would give lesser distortion in small detail areas.

The extract appears unsharp because it is over-magnified and the pixels ‘smudged’ in the enlargement algorithm. There is also some exaggerated chromatic aberration. These are very good reasons for using an appropriate focal length, rather than trying to enlarge from a wider image.

The object of the exercise is to demonstrate that there is no change of perspective between the two views. This can be most easily seen by the relationships between (a) the rear bumper of the black car and the wheel of the silver car, (b) the windscreen pillar of the silver car and the rear side window of the front car and (c) the right-hand signboards and the tree trunk.

Changing the focal length changes the angle of view but not the perspective relationships between picture elements.

Exercise 1.3 – supplementary

A couple of extra exercises exploring the difference between emphasising depth and suppressing it.

IMG_4630IMG_4633

These are two images of the same building, taken with similar focal length and from a similar distance. The difference is that the top image is taken square-on and the lower image is taken at a corner, creating vanishing points and perspective lines, the same technique used by Atget in many of his images of the petits métiers of Old Paris (see Jeffrey, 2008: 30)

IMG_4636IMG_4636-2

Of the two images above, the lower is cropped from the upper. This has the same effect as increasing the focal length and shooting from the same viewpoint.

Although the dominant (yellow) lines in both images are vertical and parallel to the frame edges, the upper image has some secondary perspective lines in the scaffold planks at the top of the image and some implied perspective lines joining the pads at the base of the poles. Cropping to exclude these perspective lines has removed most of the clues to the depth of the subject and flattened the pictorial frame.

Reference: Jeffrey, I (2008) How to Read a Photograph, London: Thames & Hudson

 

Exercise 1.3 – Line

Part 1. A selection of images using lines to create a sense of depth.

All images captured with a Canon G1-X, at the wide end of the zoom range.

IMG_4628

Classic use of a single vanishing point (top of the blue panel and the far-centre of the road) with diagonal lines leading to it from all of the horizontals in the scene. Both kerbs, the yellow lines, building bases and various string courses. There is also an implied line formed by the ground floor arches of the building at near-right.

IMG_4712

The same device but with a vertical context. The vanishing point is on the lowest floor, below the camera position and all the verticals converge there. The staircase handrails and strings also lead us downward.

IMG_4718

It is interesting that converging verticals are more acceptable when looking downward than upward. We get a sense of a high viewpoint and possibly a touch of vertigo. The vanishing point is well below the bottom of the image, so there is a risk of dragging the eye out of the image at the bottom. In this case, the handrail and the seated group act as eye-stoppers.

IMG_4694

This image combines all of the techniques of the earlier examples. There is a horizontal vanishing point near the top-centre and the converging verticals of the ground-floor columns give us a sense of height. The staircase balustrade leads us from the camera position to the centre of the image. Fortunately, the steps and handrail are near-horizontal at the bottom-right so avoid dragging the eye strongly out of the image.

IMG_4648

A similar effect, but using a curved line.

IMG_4673

This is an artificial example (a detail of the pedestal of Paul Day’s statue at St Pancras station), a low-relief bronze casting which uses line to give an illusion of depth.

Part 2. A set of images using line to flatten the pictorial space.

All images captured with a Canon G1-X, in the centre or long end of the zoom range.

IMG_4627

In this case, the subject is effectively flat and the flatness is emphasised by arranging all relevant lines parallel to the edges of the frame.

IMG_4685

The subject in this image is deeper, but presents as a series of parallel planes. By approaching it square-on and arranging the major lines parallel with the edges of the frame I have tried to eliminate the clues about separation of the planes, thus flattening the space. Unfortunately, the shelves inside the door to the left lead to a vanishing point and compromise the illusion slightly.

IMG_4753

A similar technique, suppressing clues about the separation of planes.

IMG_4720

Shooting vertically with a long-focus lens and arranging the tile pattern parallel with the edges of the frame we lose the impression of depth. The converging verticals of the balustrade are reasonably minor.