Introduction
A tool used in photography, the lens has the ability to provide a whole new facet of photo graphical applications. Day-to-day objects, when viewed through a lens, are viewed from a different perspective. However, these lenses require a good amount of technical prowess to be handled at the max of their abilities. Photo graphical technique comes into play because a macro image not only requires the image to be sharp and clear but also a creative framing ability. The concepts that many photographers are quite familiar with such as magnification, depth of field, and diffraction when working with a macro lens take on a whole new significance.
Magnification
The term tries to imply the magnified image that will be projected onto the sensor of the camera. The difference between the size of the object and the image is termed magnification. For instance, magnification is termed 1:4 or 0.25X when the object that is being viewed is 25% smaller than the image that’s being made in the camera’s sensor. The higher the magnification capabilities of a camera, its ability to fit a smaller body into the frame also increases.
Figure 1- At a Magnification of 0.25X
Figure 2 – At a Magnification of 1.0X
Magnification is controlled by just two lens properties: the focal length and the focusing distance. A lens’s magnification capabilities are directly proportional to the closest distance it can focus on. This is completely logical as the closer an object gets the larger it becomes to appear. Better magnification is achieved by a lens with a longer focal length. The least distance needed to focus may also be the same.
Proper macro lenses have the ability to present the image onto a camera sensor in the same size as the real body: it’s also known as 1:1 or 1.0X macro. Only when the 1:1 condition is met a lens can be termed as a macro lens. Many times, in a general sense, close-up photographs (till the magnification range of 1:10) are also termed as “macro”.
Lens Extension:
The apparatus of the lens is required to move away from the sensor of the camera for the lens of the camera to focus nearer. The lens is generally at a distance of one focal length from the sensor because, for low enlargement, the extension required is minuscule. In huge magnification scenes of 0.25-0.5X, the lens goes so far away that its behaviour changes as if a longer focal length was involved. At 1:1 magnification, the lens moves all the way out to twice the focal length from the camera’s sensor:
Figure 3
This video talks about the different spherical lenses and how they form images.
Stay tuned with BYJU’S to learn more about macro lenses, convex lenses, and much more.
Frequently Asked Questions – FAQs
What is optics?
Optics is a discipline of physics that deals with the properties and behaviour of light, including its interplay with matter and the creation of devices that use it.
What is a lens?
A lense is a transmissive device which disperses or focuses light beams by means of refraction.
What are the main two types of lenses?
Concave lenses and convex lenses are the main two types of lenses.
What is a macro lens?
A macro lens is a type of lens that has the capability to magnify smaller objects into bigger images.
What is an extension tube?
An extension tube is a long hollow tube that is fixed between the camera body and the lens. It allows the user to focus on objects that are very close to the camera and generate better magnification than normal.
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