The Focusing Challenge
No matter what you do, your area of sharp focus is always going to be very narrow when you get up close. We’re going to look at depth of field in the second section of this chapter, because there are some things that you can do to use depth of field effectively. Still, the closer you get, the shallower the depth of field becomes no matter what you do. This is a matter of physics, not about the gear or technique you use.
So your focus point becomes critical as shown in Figure 4.1. Very little of this image is actually sharp, yet you perceive it as a sharp photo because the important part of the image is absolutely sharp. You can’t count on this to simply happen. You have to choose very carefully what should be sharp in your picture. If you miss the right focus point for your subject, your picture will look out of focus and not sharp even if you have done everything right and there is something in the picture that is sharp.
Figure 4.1 Notice how much of this photo is out of focus, yet people will perceive this shot as very sharp because the critical parts of the little katydid nymph are very sharp.
ISO 400 • 1/800 sec. • f/3.2 • 90mm lens (APS-C)
This can make all of your best efforts go to waste. I have seen photographers get very frustrated with this, so much so that they quit doing close-up work or they start buying additional equipment in hopes of solving this problem. This is not an equipment problem. As you’ll see, it is a problem that can be made even worse by autofocus.
The key to getting your focus in the best place for your image has to do with one very simple thing—paying attention. You simply have to pay attention to where your camera is focused, what is most important in your picture, and what the photograph looks like.
For the digital photographer of today, that last point is really easy to deal with—use your LCD. This is a key part of a digital camera. Take your shot, then check the image in the playback on your LCD. You don’t have to do this all the time, but if you are not sure about where the focus is in your picture, use that LCD. Newer cameras have very high resolution in their LCDs, which make this easier to do, but all cameras can help you if you simply magnify the image. Play back your image on the LCD, then magnify it over the point where it should be sharp to be sure that it is.
Here are some tips to help you determine the best point for focus:
What is key to the composition? It should be sharp, as seen in Figure 4.2.
Figure 4.2 This tight shot of a yellow flower works because it is sharp where it must be sharp to support the composition.
ISO 200 • 1/2000 sec. • f/5.6 • 14–42mm lens (MFT)
- What is getting the strongest light? Light has a big influence on what a viewer sees in a photograph. If light is picking out a part of your subject to emphasize, then that should be sharp.
Are the eyes sharp? If you are photographing insects, spiders, or any other small critters, be sure that the eyes are in focus. People expect eyes of living beings to be sharp and if they aren’t, the picture is considered to be out of focus, as seen in Figure 4.3.
Figure 4.3 This could be a very cool photo of a baby praying mantis, but it isn’t, because the sharp focus is on its rear rather than its front.
ISO 400 • 1/100 sec. • f/11 • 90mm lens (APS-C)
- What is the boldest part of your subject that is visible in the image? If it is a bold part of your subject and emphasized by your composition, it needs to be sharp.
AF and MF
Autofocus (AF) is a very important and totally valuable technology for cameras. However, it doesn’t always work very well for close-up and macro work. That doesn’t mean you can’t use it for close-up work. I often do. But the challenge is that when you get up close, there are lots of things that your AF system can focus on, and it doesn’t know the difference between one or the other, as you can see in Figure 4.4. As soon as AF finds something sharp, it’s done! It doesn’t matter if that is the best focus point or not, because your camera doesn’t care. The camera only cares that it found something it can render as sharp.
Figure 4.4 There are so many “edges” in this image that AF could focus on, including the back eye and all of the edges of the leaves. MF was used for the shot.
ISO 400 • 1/60 sec. • f/8 • 180mm lens (APS-C)
With manual focus (MF), you deliberately focus your camera lens on a specific point within your scene. Because you are using MF, you are the one making the decision—the choice as to what should be sharp and what can be allowed to go out of focus. This does not mean, however, that MF is always the best way to go or that it is always going to be easy.
For MF, do a rough focus with your lens, then move your camera gently toward and away from your subject to refine your focus. This is a very effective way of ensuring that the key part of your subject is in focus. Things will snap in and out of focus in a much more obvious way than if you were to simply rotate the MF ring of your lens. (Obviously, you have to be careful that you’re not bouncing your camera all around or you will have sharpness problems from camera movement during exposure.)
You can use this same idea with AF, but you have to be able to lock your focus. Get in close using your AF to get your rough focus. Next lock your focus and move your camera gently toward and away from the focus point until it looks sharp, then take the picture. All cameras will lock focus by default when you press the shutter button halfway (unless you have changed how the button functions in your camera’s custom functions). Many cameras have a button on the back of the camera that is either programmed for locking focus or can be programmed for locking focus.
Regardless of how you lock your autofocus, it is important that you watch what your autofocus is doing when you are focusing up close. Pay attention to the autofocus points so that you know where your camera thinks it should be focusing.
Live View Benefits for Focusing
If your camera has Live View and you aren’t using it, get out your camera and your manual to learn how to turn it on and start using it. Live View is one of the most important technologies in digital cameras for close-up and macro work.
Live View is simply the LCD display of what your sensor sees as it looks through the camera lens. If you are using a traditional DSLR, the camera mirror is locked up for Live View, so the lens is projecting the subject directly onto the sensor and the camera is then interpreting that look and displaying it on your LCD. If you are using a mirrorless camera, there is no mirror so what you see is always what the sensor sees.
Now you can literally focus on your sensor so that the sensor precisely captures what should be sharp (Figure 4.5). In addition, you get a very important aid to this focusing—you can enlarge the image on your focusing screen in order to more precisely focus your shot. Here’s where you can use your MF and rotate your focus ring until this area is sharp because you have magnified the image to only see that.
Figure 4.5 Live View allows you to focus quite precisely by seeing exactly what the sensor sees and by enlarging the view.
Another benefit to Live View is seeing what your depth of field looks like. You have to set your camera to display the actual shooting f-stop. By default, to allow for more accurate focusing the camera shows you the wide-open, maximum f-stop of the lens, but most cameras allow you to set up a depth of field preview that shows up on the LCD.
When you start using Live View for focusing, you may find that it is challenging to do. Don’t give up! This is simply something you have to practice, just like learning to ride a bicycle. Once you practice a bit with it, you will discover that it works for all sorts of subjects that you might not have expected.