I try to persuade my students not to get too hung up with the importance of depth of field (dof) – photography books and magazines always seem to do their utmost to make it sound as difficult and as complicated as possible.
The effect of all this brainwashing is that many photographers become completely obsessed with it and get its value and importance out of all proportion. However, a basic appreciation of depth of field, and how it affects your pictures, really is a vital factor to consider if you are photographing reflections; on these occasions you often need to get the image sharp from near foreground to far distance – maximum depth of field.
For maximum depth, the smallest possible aperture should be used. It is not just the object reflecting the image that needs to be in focus, but the reflection itself, which could be some distance away. For maximum depth of field, focus on a spot about one third the way between the nearest (the reflector) and the furthest (the reflected images) points which need to be sharp. The depth of field preview button on your camera can be very useful for checking that everything will be in focus. However, if you own one of the latest DSLRs with ‘Live View’ facility this is an even better option for checking whether everything is in focus.
This mirror was positioned so that visitors to Lincoln cathedral could see the roof without craning their necks. I preferred to photograph the stained glass windows through it. I used a small aperture, f16, which meant I needed a slow shutter speed of 1/4sec. The camera was put on a tripod. Using the centre-weighted exposure mode, a light reading was taken from the window’s reflection, this has underexposed the interior of the cathedral – just the sort of contrast I wanted
Maintaining maximum depth of field is very important with pictures like this. I could afford to have the mirror itself slightly out of focus (it was very close to the camera) but definitely not the pile of scallop shells or the clouds and sky reflected in the mirror. So I focused on the shells, used the camera’s Auto Focus Lock (AFL) function, then re-framed the picture. Exactly the same result could have been achieved by using the Manual Focus mode and focusing on the shells – you really don’t need automated functions all the time… there’s nothing wrong with ‘finger power’.
The reflective surface of the water is so still in this picture that is almost impossible to tell which is a reflection and what is the real thing. Add to this the complicated structure of the salmon stakes and the image becomes an intriguing puzzle. The seagull brings a sense of scale. The stakes are sidelit, with light on one side and shadow on the other. This has helped each stake appear as a round pole – the illusion of that third dimension again on a two dimensional photograph