What is the reproduction ratio/ magnification?

Tips & Techniques

Nov 30

Reproduction ratio or magnification is a term commonly used in photography (specially in macro photography) to describe the ratio between the size of an image that an object creates on a camera sensor, and the actual size of the object.

This should not be confused with the size of the photos displayed on the computer screen or on the camera screen.

Reproduction ratio = size of the image on the sensor : actual life size

Magnification = size of the image on the sensor/ actual life size

Ex:

If an object is 5 cm high and the image on the sensor is 1 cm high,

Reproduction ratio = 1/5 = 1:5 = 0.2x

The higher the reproduction ratio, the larger the object is photographed. The maximum size that can be obtained (at the minimum focus distance of the lens) is called the maximum reproduction ratio. Typically, the lenses we use have values of less than 1:1 (1: 2, 1: 3, 1: 10..etc.), and in normal macro lenses this value is 1: 1 and in ultra macro lenses it is more than 1:1 (2: 1, 2.5: 1, 5: 1..etc.).

1:1 = 1x

Sony FE 90mm f/2.8 G
Nikon 105mm f/2.8G (NIKKOR)
Canon EF 100mm f/2.8
Tokina 100mm f/2.8

2:1 = 2x

Laowa 100mm f/2.8 2x
Laowa 60mm f/2.8 2X

As shown in the image above, the reproduction ratio range of a Sony 90mm f / 2.8 Macro lens is shown in light blue on that lens. How the Focus Distance varies is shown in orange (per unit foot) and white (per unit meter). At a minimum focus distance of 0.28 m, this lens can achieve the maximum reproduction ratio of 1: 1 (1x).