An online photography talk about the critical role of good focussing in great photography
Focus: the third critical component in successful photography was the subject of my first online photography talk of 2021. I have called it the third critical component because focus forms a holy trinity with composition and lighting. All three must come together for any photograph to have a chance of being successful, dare I say even great. If any one of these three elements is substandard in any photo then that image will be a failure.
Watch this talk here
This talk was recorded, and so you can watch it here now. Just click on the embedded link below. The talk is 40 minutes long, and I really hope you enjoy it.
What does this talk contain?
It may seem blindingly obvious, of course, to say that the main subject of a photo needs to be sharply in focus for that photo to be a success. However, correct focussing goes well beyond just this limited definition.
There are many other issues to consider, such as:
- Does the entire image need to be sharp, not just the main subject, as is often the case with landscape photography?
- Or would it be better, for example, to have the background blurred, enabling the sharply in-focus subject to ‘pop out’ of the picture, such as is common in portrait or wildlife photography?
- Perhaps you need to have just one small part of the photo sharp (containing the main subject) and everything else blurred, ensuring that attention is directed just to this area of the frame;
- What about blurred motion as the main subject? Does this need to be sharply in-focus even though it is blurred anyway as a result of movement?
Techniques and technologies
What all the above points cover is the subject of depth of field, and the need to control this in order to control just how much of any photo is sharp.
Depth of field is the amount of an image that is in focus from its nearest point (to the photographer) to its furthest point. This can be varied in a number of ways, primarily:
- A wide-angle lens naturally has a bigger depth of field than a telephoto lens;
- A narrow lens aperture (ie a high f-number, eg f/16) creates a bigger depth of field than a wide open aperture (ie a low f-number, eg f/5.6).
So, if you use a wide-angle lens shut down to a narrow aperture you will have a big depth of field, potentially ranging from shortly in front of the camera all the way to the horizon. This is commonly used in landscape photography, though also in other photographic genres.
On the other hand, if you use a telephoto lens with a wide-open aperture you will have a very small depth of field, perhaps a metre or less. This is a technique commonly used in portrait and wildlife photography to ensure the face really ‘pops out’ from its background and commands the viewer’s attention.
As the subject-to-camera distance decreases, perhaps once it is less than about 10 metres, then the depth of field starts to decrease for any lens and any lens aperture. Finally, when you get down to macro photography, such as of butterflies, the depth of field even at a very narrow lens aperture is quite tiny, usually no more than about 1 cm or thereabouts.
Further content
During the talk I show a range of images that illustrate the above points about depth of field. The final third of my talk covers some practical examples, in which I have deliberately taken sets of photos at different lens apertures and focussing distances, to illustrate how changing these, along with lens focal-lengths, can have a dramatic impact on the type of image that results.
The final section looks at the problems of macro photography and the tiny depth of field available here. In particular I introduce the technique of focus-stacking: taking a series shots focussed at different points, and then blending them together in the computer post-photography.
Overall, the talk gives a tour of the techniques and skills of good focussing, taking it well beyond the simple process of just getting the subject sharp. Instead, the aim should be to control the depth of field in an image through appropriate use of lens focal length and aperture to produce an image that works for the particular subject and its surroundings.
Find out more about my talks
I hope you enjoy watching this talk. If you’d like to find out more about my talks click on the links below, where you’ll be able to watch recordings of earlier talks, and sign up for some of my upcoming talks.
Each of my talks takes place on a Wednesday evening, once a month, and are free to attend.
I’ll look forward to seeing you online.
