Close-up and macro

macro means photographing at very close range — strictly, rendering the subject at life size or larger on the sensor.

Every problem in photography gets worse up close, and in a way that surprises people the first time.

Depth of field collapses

At normal distances, f/8 gives you metres of depth of field. At macro distances the same aperture gives you a millimetre or two.

Two consequences:

• Stop down further than feels right — f/11 to f/16 is normal, diffraction accepted as the lesser problem.
• Which plane you focus on becomes a compositional decision, not a technicality. On an insect, that usually means the eyes.

Focus by moving

At these distances, turning the focus ring changes magnification as much as focus, and the two fight each other.

The technique that works: set the focus roughly, then move the whole camera slowly forwards and backwards until the plane you want snaps in. On a tripod, a focusing rail does this precisely.

Light disappears

Close up, the lens itself blocks light, and stopping down to f/16 costs several more stops. Between them, macro is usually short of light even outdoors in daylight.

The answers: a tripod and a long exposure for anything that will hold still, or flash for anything that will not.

Starting without a macro lens

• Extension tubes sit between camera and lens and let it focus closer. No glass, so no quality loss, and inexpensive.
• Close-up filters screw onto the front like a magnifying glass. Cheapest, and softer at the edges.
• Reversing rings mount a lens backwards. Very cheap, very effective, and awkward to use.

All three will tell you whether you enjoy this before you spend on a dedicated lens.

Key takeaways

• Depth of field at macro distances is measured in millimetres.
• Focus by moving the camera, not by turning the ring.
• Close-up work is short of light even in daylight; plan for support or flash.
• Extension tubes are a cheap way to find out whether you like it.