With photography, where to focus and how much to have in focus are very important questions the creative photographer considers constantly, but many photographers abdicate responsibility to their camera’s auto-focus. This abdication is a mistake, and those who do not think about focussing are missing out on a big part of the fun of photography.
When I first began working as a press photographer cameras had to be manually focussed because auto-focus did not exist in the late 1970s. As we composed, we would focus the lens by twisting it, and sometimes we would have a focussing aid, like a split screen which became standard in the 1980s. Like the rangefinder cameras, the split screen would show two images of the subject in a centre area of the screen until the lens was focussed and then the two images would align and appear one. During the 1980s I photographed a lot of horse shows, which I covered for magazines like Horse and Hound, and Anglian Horse. I also sold a lot of prints to the owners of the horses and the riders. Focussing was an issue and one way around getting a fast-moving horse in focus was to pre-focus on the spot the photograph was going to be taken as the horse crossed it. The ‘spot might be a jump for example. Depth of field also plays a part and is controlled by the aperture, the focal length of the lens in use and the distance between the sensor and the subject. Depth of field is the distance between the nearest and furthest elements in a scene that appear to be ‘acceptably sharp’ in an image. Somewhere in a photograph, unless it is all out of focus there will also be an area of critical focus, which is an area that is optically in focus. You can learn more about all of this by having a play with numbers on this website, which is a depth of field calculator https://www.dofmaster.com/dofjs.html
Being in control of the area of the critical focus, and depth of field is important to the creative photographer because what is in focus and what isn’t gives the viewer an idea of what was important to the photographer. The sharper something is, the clearer it becomes to the viewer what the main thing in the photograph is, although sometimes defocussing and blurring a subject can also be used creatively to create questions in a viewer’s mind.
In the example above, I programmed in the Fuji x100v and the focal length of the fixed 23mm lens. I then chose to calculate the depth of field for f/2 at a distance of 3ft from the sensor and the calculator informed me of the depth of field of apparent sharpness in front and behind the 3ft which is jus 0.41 feet, which is just 4.88 inches. Such a shallow depth of field means that if you are aiming for an image that appears to be in focus around what is the main subject ‘critical focussing’ is vital.
If you are going to use your camera’s autofocus system it is vital to understanding how the camera decides on what to focus on, and it is not always a simple process. The Fuji x100v autofocus variances are described on the website here https://fujifilm-dsc.com/en/manual/x100v/menu_shooting/af_mf_setting/index.html which shows amongst a lot of other detail the diagram below
The diagram above is just a starting point for investigation into understanding how the auto focussing for a camera works. It is vital for the creative photographer to understand how their specific camera chooses to focus, otherwise the potential is for too much time to be spent ‘fighting’ where the camera focusses. I recommend spending time reading up on the specific camera in use and experimenting.
I did some experimenting with focus as walked around the Ipswich Waterfront. I noticed the huge number of chains, which could easily become an interesting project, but this time I chose one chain to use to demonstrate why focussing and depth of field is so important.
The two images above were taken from the same spot without moving my feet, although I did more the camera slightly, and changed the aperture. I have lowered the camera to make image 2 to make the post and the chain seem more powerful in the composition. Because I am close to the chain, the widening of the lens aperture from f5.6 to f2 has a big affect to the depth of field, especially when I focus the camera on the post, as seen in image 2. For the reader with an expert eye you might have noticed that I have missed-focus if we are talking ‘critical-focus’ because I meant to focus on the point where the chain meets the post, and yet it is on the third chain link from that point. If you did not notice, or if it does not worry you then I have got away with it due to what appears to be in focus.
For me, both images work well. In image 1 the viewer can see all the detail in the boats and buildings, and then the out of focus chain catches the eye, but right next to the chain is the dog which is apparently sharp so the eye rests on it, even though it is close to the edge of the composition. In image 2 the chain and the post is obviously what the photographer wants the viewer to look at, but with everything else out of focus there is an edge of mystery created. Mystery can engage a viewer, and often lead to an image being viewed for longer, and being more memorable because it does not give the viewer all the answers easily.
This article on focussing is titled ‘1’ because I will be adding more posts about this creative process in the future.
If you have anything to add to this conversation of any questions please use the comments box below.