‘Find a subject in front of a background with depth. Take a close viewpoint and zoom
in; you’ll need to be aware of the minimum focusing distance of your lens. 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.
The closer you are to the subject, the shallower the depth of field; the further from
the subject, the deeper the depth of field. That’s why macro shots taken from very
close viewpoints have extremely shallow depth of field, and if you set the focus at
infinity everything beyond a certain distance will be in focus.
As you review the two shots, how does the point of focus structure the composition?
With a shallow depth of field the point of focus naturally draws the eye, which goes
first of all to the part of the image that’s sharp. It generally feels more comfortable if
the point of focus is in the foreground, although there’s nothing wrong with placing
the point of focus in the background.’
This series was shot using a Vivitar 28mm f2.8 fully manual lens, converted from an old film camera, for use with the Canon EOS series. (28mm on cropped sensor equates to around 45mm on full frame sensor) So, apart from having no auto-focus features, this means there is no EXIF data collected from the lens, so I had to note everything down by hand. I also had to make use of exposure compensation quite a lot, as metering with this lens seems to be way off.
Camera: Canon EOS 1300D. Mount: Tripod. Lens: 28mm. Aperture: f5.6. Focal Distance: 0.3m ISO: 200. Exposure Compensation: -1
Camera: Canon EOS 1300D. Mount: Tripod. Lens: 28mm. Aperture: f5.6. Focal Distance: Infinity. ISO: 200. Exposure Compensation: -1
This pair of images demonstrates very well how focusing on a close object, even with a medium aperture setting, blurs out the background, and vise versa, when focusing on the distance.
Finding a scene where the close object and background scene are of equal interest proved quite challenging, but on this one at least, I’m quite happy. There’s something about rusty metal that I find visually appealing, while canal scenes have a very calming sense of nostalgia.
Camera: Canon EOS 1300D. Mount: Tripod. Lens: 28mm. Aperture: f2.8. Focal Distance: 0.9m. ISO: 200. Exposure Compensation: -1
Camera: Canon EOS 1300D. Mount: Tripod. Lens: 28mm. Aperture: f2.8. Focal Distance: 10+m. ISO: 200. Exposure Compensation: -1
Without auto-focus, focusing on the iron gate proved very difficult. The light was poor, while the gate was in shade and of a very dark colour itself. Tricky.
It’s worthy of not that, despite using a wider aperture, because the camera was further from the close object (the gate) than in the previous pair of shots, the background when focusing on the gate is still fairly visible and identifiable.
Camera: Canon EOS 1300D. Mount: Tripod. Lens: 28mm. Aperture: f2.8. Focal Distance: 9m. ISO: 200. Exposure Compensation: +0.3
Camera: Canon EOS 1300D. Mount: Tripod. Lens: 28mm. Aperture: f2.8. Focal Distance: 15m. ISO: 200. Exposure Compensation: +0.3
In the first image, I focused on the ‘Play Areas’ sign, but with a focal distance of 9 metres, despite the wide aperture, the background remained fairly well (if not quite perfectly) focused.
In the 2nd image, while focusing on the church, the sign blured out a little, but not to the point that it is illegible.
This exercise has proven very useful in demonstrating the effect the distance from a foreground object has on depth of field. Regardless of aperture, a very close foreground object will produce a shallower depth of field, and the further from it you get, the deeper the depth of field becomes (albeit potentially limited by aperture setting).
I learned something else from the exercise too.
Working with a fully manual lens is very satisfying. It forced me to slow down, as not only did I have to fiddle with the lens to set the aperture, and then tweak it by fractions, to try and achieve a good focus, I also had to pause between shots to note down the settings for each shot.
The result of this, when compared with the shooting I did in Sheffield using the kit lens, was that I was far more careful and deliberate about what I was doing. While this had downside of removing much scope for opportunistic shots, I found the shots I did take were better composed… or rather, it took far fewer shots to achieve the correct composition.