Rhys Hanak - September 13, 2018
For most people, the aperture of a camera system is not something that often crosses their minds. After all, with today’s modern technology, one does not need to understand the inner workings of cameras (which is a complex field of study, shrouded by mathematical equations and technical terminology) to capture great pictures. But with 85% of all photos being taken by a smartphone in 2017, apertures probably play a much bigger role in your life than you think—and as lovers of all things optics, it is both our duty (and our honour) to shed some light on this often misunderstood topic.
OK so really: what is an aperture?
It is no overstatement to say that aperture is one of the most important elements in the imaging process.
Aperture, which is essentially the hole in a camera whereby light passes through onto a sensor, shares a striking resemblance with the pupil of the human eye.
Note: Our eyes are even biologically classified as “camera-type eyes”, which is one of the 10 different eye layouts seen throughout nature.
To explain the relationship between human pupil and machine aperture, let’s first review the science behind human vision.
The cornea of our eye, which can be thought of like the front element of a camera lens, gathers light and bends it towards the iris. As the iris shrinks, our pupils either increase or decrease in size, letting in variable amounts of light.
This light then ends up on the retinas of our eyes, allowing us to see…
In sum: the larger the pupil, the more light that enters the retina. Similarly, the larger the aperture of the lens, the more light that enters the camera.
Aperture size plays a critical role in photography. It is commonly expressed in terms of “f numbers” or “f-stops”, which also describes how open or closed the aperture is.
Note: F-numbers are calculated by focal length ÷ aperture
Note: In fixed focal length systems, a smaller f-stop traditionally means a larger aperture, while a larger f-stop means a smaller aperture. This rule, while initially confusing, is foundational in understanding apertures.
Why is a big aperture important?
In simplest terms, the bigger the aperture, the more light you can collect; when an imaging system is able to take in more light, it can capture both higher resolution images and better low-light images.
And despite the fact that modern image processing software plays an important role in capturing high-quality images—it also has its limitations. As the old saying goes…
“You can’t make a silk purse out of a sow’s ear.”
– Jonathan Swift (1667 – 1745)
It stands to reason that imaging devices should not rely on software alone to create great pictures. Instead, it is the combination of both cutting-edge software and innovative optical design that creates a truly remarkable imaging experience.
What are the limits of light gathering?
To understand the limits of light gathering, one first has to understand the principle of diffraction. Diffraction, which is defined as the spreading of waves around obstacles, is a natural phenomenon that occurs throughout nature.
Diffraction occurs in all waves of energy, be it light waves, sound waves, or even the waves that you see in water.
In the context of optics, diffraction is what sets the upper resolution limits of each and every imaging device; as such, it represents one of the optical engineer’s eternal challenges. As a creative optical development firm, we are constantly pushing these fundamental limits to design cutting-edge optical solutions.
What makes a Blade Optics™ aperture different?
Anyone can design a lens system with a big aperture.
The challenge lies in creating a lens system with a large aperture in a compact space—this, at the heart of the matter, is what makes Blade Optics™ so special.
As a patented geometric solution, Blade Optics™ utilizes optical blades (a combination of different optical folding techniques) to allow for large apertures in compact spaces, all the while maintaining almost diffraction limited performance.
By enabling more compact imaging applications (that can also see farther, and with higher resolution), we believe that Blade Optics™ technology opens up a new world of opportunity for the design of creative imaging products.