Focusing on subjects

To focus, you turn the lens until your subject looks sharp. Most cameras give you an aid in the viewfinder to make it easier to judge. This page covers focusing SLRs, TLRs and rangefinders by hand, autofocus, and zone focusing for quick shots.

Focus types in film cameras

Type	Control	Best for
Manual focus	You set it	Full creative control
Autofocus	Camera sets it	Speed, later cameras
Fixed focus	No adjustment	Disposable cameras, convenience

Manual focus is easier than it sounds. Most cameras have built-in aids to help you.

Fixed-focus lenses keep everything sharp from a set distance to the horizon. Anything closer than that comes out soft.

Focusing an SLR

Turn the focus ring on the lens to move the lens elements and bring your subject into focus.

Your viewfinder has a focusing screen with aids:

• Split-image: a circle that splits the image in two. Align the halves to focus.
• Microprism: textured ring that looks jagged when out of focus, sharp when correct.
• Matte screen: fine texture that works well in low light.

Focusing a TLR

Twin-lens reflex (TLR) cameras, such as the Rolleiflex or Yashica, use a side-mounted dial to move the lens assembly.

Instead of a prism, you view through a waist-level screen. This larger screen makes focusing easier, especially from lower angles. Some models include a flip-out magnifying glass for precise work.

Focusing a rangefinder

Rangefinders, such as the Leica M series, use a coincidence system. You see a secondary image overlaid in the viewfinder.

Turn the focus ring until the two images align. The system works best with subjects that have clear edges or contrast.

Framing close subjects

On a TLR or rangefinder, you look through a different window from the one the lens sees through. Up close, the picture is shifted slightly from what you saw. This is called parallax. For subjects nearer than about a metre, leave extra space on the side of the frame nearest the viewing lens.

Focusing with autofocus

Later autofocus SLRs (such as the Canon EOS range) use electronic sensors and motor-driven lenses.

Mode	How it works
Single (AF-S, One Shot)	Focuses once when you half-press, stays locked
Continuous (AF-C, AI Servo)	Keeps adjusting while half-pressed, tracks moving subjects
Manual override	Switch to manual after autofocus locks

Half-press the shutter to activate focus. A light or a beep usually confirms it.

If autofocus picks the wrong spot, try recomposing or using manual override if your camera has it.

Zone focusing

Zone focusing uses depth of field instead of precise adjustment. Most lenses have distance markings and depth of field indicators on the barrel.

To use zone focusing:

1. Set a small aperture, such as f/8 or f/11.
2. Turn the focus ring to the distance your subjects will usually be, such as 3 metres.
3. Read the depth of field scale on the lens barrel. The two f/8 marks either side of the centre show the near and far limits of what will be sharp.
4. Shoot without refocusing, as long as your subject stays between those distances.

The depth of field calculator shows the range for your lens.

This works well for street photography. You can catch a candid moment quickly, without lifting the camera to your eye.