Exercise 2.7 -Wide-angles and deep focus

In this exercise we explore wide lenses and small apertures to produce scenes with deep depth of field. Of the mechanical exercises in Part Two, this is the one I found most difficult because I am uncomfortable with wide angles. I do not particularly like the associated image distortions and I find the backgrounds, although receding, are intrusive because of the difficulty in excluding disturbing elements from the frame.

All of these images were shot using an Olympus E-30, fitted with a 9-18mm wide-angle zoom. The 2.0 crop factor means that the 35mm equivalent zoom range is 18-35mm or ‘very wide’ to ‘short standard’. There is more variation in focal length than Exercise 2.6, where I mostly used 50mm (100mm equivalent) which I find easy to compose with. In most cases, the aperture was set at f/11.

All images were shot at ISO200 with aperture-priority evaluative metering.  This has led to some significant exposure variations within sequences, depending on the amount of sky included in frame. All images were shot in RAW and exported unedited (apart from resizing) from Lightroom.

Sequence 1 shows a recently-cleared piece of woodland. After the first two images, I adopted a lower viewpoint switching between foreground stumps and between portrait and landscape formats. The portrait shots emphasise depth but I found the arrangement of stumps became rather linear. In both selected images, the stumps form a zigzag leading into the frame, the top of which is held-in by a dark line at the base of the trees behind.

Sequence 2 is in a bike-park. The first four images are at various focal lengths between 12mm (24mm) and 18mm (36mm), after which I settled on 9mm (18mm) and varied my viewpoint. In this case, higher viewpoints (above handlebar level) gave a more extensive view and better sense of space. One problem is the pink bike at the left of foreground, which is intrusive when broken by the image frame.

In sequence 3, I was initially interested in the lifering and the rowing boat. Then the silver birch suggested itself as a third element.

Again, I present some non-sequence images that I was happy with.

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Exercise 2.6 – Shallow DoF and composed bokeh

This exercise explores wide apertures, coupled with long focal lengths and close viewpoints to produce images with shallow depth of field. So far, so easy, but we also have to compose the bokeh rather than ignoring it.

Common technical details: all images are shot with an Olympus E-30, having a crop factor of 2.0. The indoor bowls images are at ISO2000, all others are ISO100. Metering is aperture-priority automatic.

All images were shot in RAW and exported unedited (apart from resizing) from Lightroom.

50mm (100mm equivalent) wide open at f/2.8, shutter speeds automatically set between 1/60 and 1/125. My selection is the final image. If I were editing in Lightroom, I would crop to eliminate some negative space at the right, open the shadows a little and set a post-crop vignette to ‘hold in’ the frame edges.

50mm (100mm equivalent) wide open at f/2.8, shutter speeds automatically set between 1/250 and 1/400.

50mm (100mm equivalent) wide open at f/2.8, shutter speeds automatically set between 1/100 and 1/160.

A few more selected images from the exercise:

Exercise 2.4 – Mugshot

This image was shot with an Olympus E-30 and 50-150mm (100-300mm equivalent) f/2.8-3.5 telephoto zoom lens. Settings, ISO100, 50mm (100mm equivalent) focal length, aperture-priority automatic at f/2.8. Shutter speed was 1/50 second. Minor tweaking in Lightroom, including a -13 post-crop vignette.

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The eyes are near the horizontal centre-line. The left eye is almost dead-centre and our first point of focus. The right eye is somewhere near the third-line. Mostly, the eye is held by the model’s gaze; the out-of-focus background directs us back to the in-focus face and the stray wisps of hair accentuate the difference between subject and bokeh.

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.

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

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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.

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).

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Focal length 42mm (84mm equivalent)

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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.

Collecting • further thoughts

Some views of a random bike, trying out focal lengths and viewpoints.

In the context of the assignment brief, the best images are those in which the subject almost fills the frame. Minimum distortion occurs at the long end of my standard zoom, 42mm (84mm equivalent) and a viewpoint 4-5 metres from the subject. The frame can be filled at the 14mm (28mm equivalent) end of the zoom range and about 1.5m from the subject, but there is no valid reason for introducing the associated distortions.

An alternative approach is to use the long end of the zoom to extract details.

This will be my fallback plan if I cannot make my original idea work.

Even with the bicycle filling the image frame, there is a lot of background visible. Ideally, this should be de-emphasised by differential focussing, requiring a wide aperture. My next experiments will be made using an OM-system 50mm f/1.4 lens. Initial results suggest that it is a little soft at f/1.4 so I will work with it at f/2, which is wider than anything I have in my E-system kit. However, with no auto-focus and no focus-confirmation aids (microprism or split-image) it will take some practice.

A further thought is that series of similar images, such as I intend, will be a typological exercise similar to the work of Bernd and Hille Becher, who will be the subject of further research. (example below)

 

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.