Exercise 2.7 deep depth of field

Why yes, this exercise is rather late. I did try it at the time, and encountered every problem listed in the blurb. I started wondering if my camera was cleverly engineered to ignore the laws of optics and physics and be the only budget dslr to offer bokeh at f22. Now looking down the barrel of A5 and willing to do anything other than attempt making a handmade book (what if it doesn’t work?) it was time to try it again.

My first attempt was with the array of my daughter’s Disney Infinity figures. Tripod, remote shutter release, long exposures… results not bad in terms of front to back focus but not really a decent image. I put the camera in the back of the car along with my climbing gear, and took a few images of the traverse wall and lockers after a climbing session. It was busy, so I didn’t use the tripod but instead upped the ISO and braced myself against the wall.  I worked with my wide-angle lens and the narrowest apertures I could. I tried to remember what I’d learned about hyperfocal distances – basically if you focus in between the scene and you, the in focus distance will be greater than you expect.

My selects are the following two shots, though the focus is still nothing to write home about. I need to retry on a quieter day with a tripod.

ex2.7 dof-7218

ex2.7 dof-7226

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Project 2 Depth of Field photographer research

Deep depth of field is achieved via a narrow aperture and a wider lens helps. It results in more of the background being in focus, in many cases photographers work towards everything being in focus from the front to the back of the image. For example, Gurski, Ansel Adams, Vitali. Control over how the image is viewed is handed to the viewer, who is not compelled to start with the areas in greatest focus. Landscape and staged photography often use this technique, as do factual, product and documentary images.

Shallower depth of field can be achieved via a wider aperture or a zoomed lens. It allows the photographer to choose which elements are in focus and can therefore direct the viewer’s attention to those areas by effectively blurring out the others.  A bridal portrait for example will probably have a shallow depth of field compared to a passport photograph which has to be pin-sharp throughout. Shallow depth of field can provide a way to minimise the effects of a disruptive background, but does so at a cost of lost information in the image.

Ansel Adams worked with a small aperture and a large format camera for sharp DOF front to back. He wanted to move away from the artistic interpretation of pictorialism to accurate renditions that looked like photographs and not paintings. He made extensive use of dark room techniques to improve areas where he felt God’s work was lacking. “Dodging and burning are steps to take care of mistakes God made in establishing tonal relationships”. I found this statement a little surprising.  He made dramatic photographs of dramatic landscapes, full of light, shade and texture.

Fay Godwin impressed me  with her careful and accurate framing. I think it is this framing that makes her exploitation of depth of field both possible and quite so effective. She worked with a deep depth of field in images which showed man’s interference with the environment. Living near Avebury I’m familiar with the rose-tinted art of photographing ancient rocks so that it looks like nothing has changed over the millennia.. hence leaving out buses, roads, people, and blurring the background, shooting in the golden hour or the dead of cloudless nights. Of course, living in Wiltshire I’m also aware that most of those stones were disinterred and re-erected in the 1940s/50s, into a vision of what one amateur archaeologist thought they used to look like, but that’s another story. Godwin’s work seems honest, she shows how our natural and historical places were disrupted and closed off to the public. This is adding a political dimension to the accurate beauty of Adam’s work. Godwin was born in 1931 to  British/American parents in Berlin. After starting in portrait work she specialised in landscape work and was both president and vice-president of the Rambler’s Association, using her work to support their campaigns for open access and restoring public rights of way to our countryside.

Gianluca Cosci uses the opposite approach in Panem et Circenses with “slivers of sharpness” showing corporate power in urban spaces. He is very precise about choosing what is in focus, it could be a single small weed, a leaf, a single edge of a paving block. The work made me think about what is natural in our environment and what is man-made. Senzo Titolo #4 seems to show trees growing from concrete in the background and the foreground shows moss in the cracks in the paving. There’s a conflict suggested between the natural and urban environments. Sometimes you have to look hard for the single point of focus. I realise how much of the natural/beautiful world is obscured by construction and corporate metal, glass and plastic. Born in 1970 he now lives and works in Brussels.

Mona Kuhn uses shallow depth of field in her portraits. She uses dof to help challenge how we view her work. I like the work because it is not just about dof blurring out the background, it is often about using dof to blur out the subject too, as women blur into the background behind a flower or plant. She also uses screens, curtains, blinds, reflections, tents, shadows to this end too… I find it really engaging in its lack of obviousness. I prefer it very much to Guy Bourdain’s more obvious work. I like the light that she uses too. Words I have noted are simple, dreamlike, feminine,  honeyed, rich, light. American, born in Brazil 1969, she has photographed in a remote French nudist community and more recently in the Californian desert.

Kim Kirkpatrick‘s work is a hymn to the little things, the detail of colour and form. Use of very shallow dof mercilessly blurs out everything non-subject and the work is almost abstract in quality.

Below are two photographs from my archive taken at Heligan, Cornwall that demonstrate shallow depth of field.

project-2-dof-bison-1
1/4000 sec @f4.0, 100mm, ISO400
project-2-dof-flowers-1
1/1250sec @f3.2, 100mm, ISO400

 

Exercise 2.5

“Find a subject in front of a background with depth. Take a close viewpoint and zoom in… 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.”

I struggled a bit with this exercise, even though I understand the concept. I don’t have many lenses and until a fortnight ago none of them except the macro had a distance dial that I could set to infinity. I got into the habit of using hyperfocal distance (with varying degrees of success). It is fair to say that I struggle with getting a shot with both close foreground and far background elements in focus without the use of a very narrow aperture, long exposure and a tripod and even then it’s often not how I want it. Also, because I’ve never had the ability to set to Infinity I don’t know exactly how to use it, in fact so far I’ve managed to forget that it’s there, with the exception of these exercises. Do I need to be in AF or MF or does it make no difference? If I’m in AF then what do I auto focus on? Does it make any difference that I normally work with back button focus? I need to follow up on these questions.

Having now done this… thanks everyone – I know to use Manual focus, focus at the back, and to adjust the aperture depending on how forwards I want the focus to extend (a narrower aperture will give a deeper zone of focus than a wider aperture). That said, in daylight I normally shoot in AF and I don’t really see any reason to change this. I will reshoot for this exercise using MF, but for the moment here is a pair of images one with the focus on the foreground object, and one with the focus behind that object. Both images are 70mm f4 ISO 100. Thank you to Clare Brooks for permission to photograph in her garden.

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.”

I felt as if I was getting back into my technical comfort zone here. I used a 50mm prime lens as it works better in lower light (supports wider apertures) and the aperture that I chose remains constant in AV mode. I wanted this light because it picked up the honey tones from the walls and worked well with Clare’s colouring, hair and outfit. If I was to take it again I would drop the ISO and use a tripod, probably taking the aperture to 2.8 rather than the 1.8 I used here.

ex2.4 portrait good light-4587

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!”

Again, I was frustrated by the fairly narrow angle of the widest end of my zoom, especially combined with my cropped sensor camera. The composition here is poor, as is the straightness (I didn’t straighten as I didn’t want to lose the distortion around the edges of the frame). You can however see the verticals and arches going all over the place in the background, and the wall seeming to tilt inwards on the left hand side.

update – this remains one of my least favourite images, not least because of the very poor composition. It does do the job though so I am reluctantly leaving it in.

ex2.3 wide angle portrait-4577

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.”

This was an interesting exercise, not least because of the unexpected dizziness from walking and zooming at the same time. It was another moment of frustration with my entry-level zoom, which has a different minimum aperture at the wide end to the narrow end, and which caught me out again. I’ve now bought a lens with a smaller zoom range but a constant aperture at all focal lengths. I couldn’t frame the two images exactly the same way, and I also managed to shift position so that the window is visible in the wider shot. Another issue is that I use a cropped sensor camera so 18mm is closer to 29mm, which is not wide at all.

I don’t enjoy making portraits with a long zoom, the available settings always seem to be a compromise and I prefer to work with primes where you make a setting and it stays put. I also prefer to use my camera in manual mode. I’m hoping that the new zoom will give me higher quality images with a workable range, so I can then forget about the kit and get back to the photographs.

So not my best results. The left hand photograph is not straight, and I didn’t want to straighten it in case I lost too much of what makes it a zoomed image. You can see that there is a much wider perspective on the image taken at 18mm with me almost in Clare’s face. The image taken at 135mm has less showing to the sides and above Clare, and the background is more blurred. Somehow one image is at f5.6 and the other is at f5, I was sure that I was in AV mode and that I didn’t change the settings, but I can’t see any other at to account for the difference given that I was manually setting the ISO too and that was the same for both images. I think I should reshoot this pair, somewhere with better light.

 

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.

I took these at Lacock Abbey. The sequence I had in mind was in the cloisters, however I took another sequence in an upstairs corridor that I found more interesting, you can see how the corridor seems to shorten and the stairs move closer as the focal length increases. There is camera shake visible on the last two images, I’d like to re-take this sequence with either a tripod or a higher ISO (I used ISO800 for these).

On looking at the exif data I realised that even though I’d been shooting in AV mode I didn’t have the same aperture for each image. I tend to work with prime lenses and had forgotten that my zoom lens doesn’t have a full aperture range available from one end of the zoom to the other.  Using the zoom lens, as I increase the focal length  the “widest” aperture available to me decreases rather than the selected aperture remaining constant throughout. Hence my realisation that neither of these series were at a constant aperture, despite my setting the  camera mode to AV. Both environments were not well lit so I had selected the widest possible aperture, which then become unavailable to me as I increased the focal length of the zoom. So I’d met the requirement to work in AV mode but it hadn’t been implemented by my lens in the way that I’d expected. That will teach me not to set and forget. For the sake of completion I will take another set at a constant aperture (ie one at f5.6 or narrower) and add that series here. The sets with varying apertures are not affected in terms of composition or showing the effects of changing the focal length, but they will show larger variations in the histogram and depths of field.