Auto-focus on modern cameras is great. It is often very precise, and makes it a lot easier to shoot photos quickly. However, it’s not always perfect, especially if you’re trying to focus on something with a lot of different elements that are at slightly different distances. If you’re using a wide aperture, with less depth of field, it’s possible that part of your shot may be out of focus. You may even see this on portraits, where part of a face may be sharp, and other parts soft.
Most good modern cameras also offer a manual focus option. You won’t find this on a point-and-shoot camera, but any camera with interchangeable lenses, and some without, give you the possibility to focus manually. One of my two cameras is the Olympus Pen-F, which offers manual focus, and has some “Focus Assist” features which are really useful.
First, you want to set the camera to use both auto and manual focus. Go to the Custom Menu > AF/MF > AF Mode > Still Picture, and select S-AF+MF. This means that the camera will use single auto-focus when you press the shutter halfway. But if you want, you can also use the focus ring on your lens to adjust focus; just start turning it while you’re holding down the shutter. When everything is ready, press the shutter the rest of the way to shoot a picture.
What’s really useful with this camera, however, is the MF Assist settings (at Custom Menu > AF/MF). You have two options: Magnify and Peaking. If you select Magnify, the viewfinder or back LCD zooms in on your focus point, making it easier to see if you’re precisely in focus. This is a 10x zoom, and, as you’ll see, gives you a very good close-up allowing you to make sure that your subject is sharp.
The second option, Peaking, displays white lines that highlight the areas in focus. You can adjust the color and intensity of these lines in Custom Menu > Disp/PC > Peaking. You can change the intensity and color of these lines.
Here’s a shot of the Pen-F focusing on a pen holder a few feet away:
When I start moving the focus ring in the lens, here’s how it looks at 10x zoom:
Remember, the camera zooms in on your focus point, so if it’s not centered, you won’t see the zoom at the center of the image.
I find that the Magnify setting is much more useful than Peaking. I don’t like the intrusive lines, though they may be useful for certain types of photos (such as macro photography). But with the Magnify feature turned on, I can make sure that I’m always in focus.
You can also use this in pure manual focus mode. As soon as you start moving the focus ring on your lens, the camera zooms in. I find this a bit more distracting, since it’s harder to compose images, but if you’re shooting on a tripod, this is a lot easier to use, since you’ll first compose your image in the LCD, then focus; you won’t need to worry about holding down the shutter half way then shooting.