I started photography with a K1000 camera which required manual focus and had a cat’s eye style focusing screen. It was very apparent when I was focused at the wrong distance because the top and bottom halves of the image were misaligned and fuzzy looking. Digital SLR’s, however, don’t have this kind of screen and manually focusing them is difficult. Mirrorless cameras have something better: Focus Peaking.
I love using Lensbaby lenses, which are all manual focus, and I love that focus peaking lets me get super sharp images even when manually focusing.
Focus peaking has been used in the video world for a long time to help them see exactly what is in focus. When you use focus peaking, the camera simply puts a colored highlight around the edges of whatever is in focus. This colored highlight is easy to see and makes manually focusing simple.
Choose the Color
You can choose the color of the peaking you see in the viewfinder. Choices vary from yellow to red to blue to green. Check your camera’s menu to see what options are available in your camera model. I’ve asked a lot of videographers which color they prefer, and it seems that most of them prefer red–if you’re color blind, that may not be the best choice. You should pick a color that is easy for your eye to discern.
Shoot in Black and White
If precise manual focus is important for your work, then you could switch your camera to shoot in black and white when manually focusing. Black and white makes it easier for the camera to detect the edges of things, and it makes the colored peaking very apparent to your eye so you can see clearly which things are in focus. Some cameras even have the option of turning your viewfinder black and white while recording video (but the recording is still color) so you can focus more precisely.
Choose the Sensitivity
Most cameras let you choose the sensitivity of the peaking, as well. At low sensitivity, your peaking will be more precise because it requires the image to be sharply focussed before it will show you the peaking highlights. At high sensitivity, you’ll see the peaking more readily because the camera isn’t as picky. I usually keep mine set to low.
Your camera is looking for edges, so if you’re shooting very close up on a flower and filling the frame completely with the petals, you may not see any peaking because there are no edges in the frame. In situations where you can’t clearly see the peaking, you should bracket your focusing, just as you bracket exposure for HDR. Focus, shoot, focus a little closer, shoot, focus a little farther and shoot again. This will ensure that you get the focus where you want it. If you bracket your focus enough you could even use focus stacking to put all the images together into one.
Manual focus can be frustrating, but focus peaking takes away the problems and lets you get a sharply focussed picture under any situation. It’s great for macro work because your camera may not be picky enough about your focus. It’s also great for low light because the camera will still show peaking even though it’s too dark for the autofocus to work. You should switch to manual focus, adjust the color and sensitivity of your peaking, and practice focusing so when the situation arises you’ll be ready to focus like a pro.