Using a combination of small apertures and a wide lens settings, I took a number of photo’s as part of my studies into the ways you can use deep and shallow DoF to affect the interpretation of an image.
The image below is a fairly typical shot with a lot of DoF. Although it has been taken at the maximum focal length (105mm) for the lens, it is very much a ‘Landscape’ image with a lot of DoF. Where many landscape shots fall down (including this one) is that there is no foreground interest. Composing a landscape shot with some kind of foreground interest gives a picture so much depth (not to be confused with Depth of field) and allows the eye to travel through the photo.
f13 @ 1/125, Focal length 105mm, subject distance infinity, ISO 800
I have rectified the problem with the first image by introducing some foreground interest. I have, in doing, had to open up the width of the lens.
f16 @ 1/15sec, focal length 35mm, subject distance 4.5m, ISO 800
Another issue which becomes apparent is that of how much you can get in focus in the foreground. I have downloaded an app on my phone which allows me to punch in the details of my camera and lens. Then by selecting a combination of aperture, shutter speed and ISO, using a slider I am able to calculate minimum distances to object, to obtain required DoF’s and Hyperfocal length as well.
So using the image below as a good example, using my app, I was able to determine that if I stood 3.4 mtrs from the sign, I could get it in focus as well as the background (subject to setting the camera up as shown below). This is quite a strong image because the balance, composition and depth are all complementing each other.
f16 @ 1/10sec, focal length 32mm, subject distance 3.4mtr, ISO 800
The sequence of shots below are taken using similar settings to the above shots. However the ‘feeling’ that these give out are quite different. In each of these shots I have set a foreground, but this time the foreground covers the majority of the image. This gives an overall feeling of closing in the focal length, whereas in fact, they are the same or close to the two images above.
The first thing that becomes apparent when shooting with a small aperture is that, because there is a lot less light hitting the sensor you need to either make adjustments within the camera or use a tripod. You can increase the sensitivity of the sensor by increasing the ISO (the way this works in a film camera is ‘actual’ because the higher rated ISO films are actually more sensitive to light, whereas in a DSLR there is no ‘actual’ sensitivity increase, it is more a case of technological manipulation/simulation), or decrease the shutter speed i.e. allow more time for the light to hit the sensor. By doing this, you increase the time that the camera is able to move if being held by hand. This can be negated by the use of a tripod. There is another way to increase the sharpness of an image ‘in camera’ and that is to make use of the ‘exposure compensation’ facility. In doing so you increase the shutter speed, but this does mean that the end result may be underexposed. Of course this can be sorted out in post production, but may result in some loss of data where there is too little light hitting the sensor.
I see! 