What Is a Macro Lens?
A macro lens is specially designed for macro photography, allowing for close-up shots of small subjects like flowers and insects. These lenses are capable of achieving a magnification of 0.5 to 1.0x or more, meaning the size of the subject on the image sensor is close to or the same as its actual size. Typically, macro lenses have a single focal length with a small maximum aperture f-number (around f/2.8), enabling them to capture bright images.
Uses of Macro Lenses
Macro lenses are ideal for capturing sharp, detailed images with increased depth of field. They allow photographers to blur the foreground and background, focusing attention on the subject, and achieving higher shooting magnifications. The depth of field becomes shallower the closer the subject is to the camera, especially with smaller f-numbers and longer focal lengths.
Principle of Macro Lenses
Macro lenses typically have a focal length of 50mm~60mm for a full-size image sensor. A shorter focal length (around 15mm) would categorize the lens as a wide-angle lens. These lenses are known for their shallow depth of field, which is the range in front of and behind the subject that appears sharp in an image. For example, a 50mm macro lens with an f/2.8 aperture will have a depth of field of just 7mm at a 30cm shooting distance.
Structure of Macro Lenses
Macro lenses are composed of multiple lens elements arranged in groups to correct for distortions and aberrations. They have complex constructions, like 6 elements in 5 groups or 9 elements in 8 groups, and are designed to move the lens forward more than standard lenses to reduce the minimum focusing distance.
Types of Macro Lenses
Macro lenses can be categorized based on their focal length in the 35mm format. They are not just limited to close-up photography and usually feature both autofocus (AF) and manual focus (MF) modes.
1. Standard Macro Lenses (50-60MM)
These lenses have a very short minimum focusing distance for close-up images. MF shooting with a tripod is often necessary for precise focus.
2. Medium Telephoto Macro Lenses (Around 100MM)
These lenses are suitable for photographing subjects a few meters away without disturbing them, such as insects or small wildlife. They are also versatile for portraits, landscapes, and wildlife photography.
3. Telephoto Macro Lenses (Around 200MM)
Telephoto macro lenses are used for capturing distant or high subjects, offering a larger field of view than standard or medium telephoto lenses. They allow for more dramatic compositions due to their narrower angle of view.