Focal length

In this exercise we are asked to take images of a subject using exactly the same framing on the face with different focal lengths using at least different lengths.

I asked my son's girlfriend to be the subject for this exercise. The shots were taken outside on a typical summer's day: windy and raining. The need for shelter obviated against taking some wider torso shots so I restricted to three framing sets: looking right, looking at the camera, and looking left. I used the first and second of these sets, there being no additional learning benefit from including the third.

I used my Canon 450D on a tripod. I do not include all the technical data on each shot for this exercise (the focal length is all important) but for the record, I used two lenses: 24-105mm and 70-200, moving the tripod successively further away. All shots were taken with aperture 13, and most were between 1/45 and 1/90 shutter speed.

There is a degree of post processing; I tried to standardise the changes across all images.

I set out below the first set of images:

focal length 24mm

focal length 45mm

focal length 70mm

focal length 91mm

focal length 131mm

It is clear from this set of five that proportions of the face do vary according to the focal length. It is logical: think of the effect of looking through a peep hole in a front door - the face outside is very distorted with the nose typically taking up half or more of the face. The changes in this set are quite subtle - certainly the first two wider angle images are not as good as the last three. These are better proportioned and somewhat flatter - it is almost as if the two dimensional effect requires a longer lens; what I notice here is that the wide angle effect diminishes quite quickly; the last image is probably the best but not by much.

Here is the second set of images - looking at the camera:

focal length 24mm

focal length 35mm

focal length 58mm

focal length 75mm

focal length 126mm

The general conclusion from reviewing this set is the same as above: the longer focal lengths are better images - the last is especially satisfying, albeit helped by the wind. The first two images are not satisfactory - the first is almost an "in your face" appearance. What is especially significant here is how much more pronounced the contrast between focal lengths is when the subject is looking at the camera rather than away.

I learnt from this exercise two main outcomes:

1) that longer focal lengths do work better; the facial features are more flattened and truer in relative size to one another;

2) that this is especially true of images facing directly at the camera.