Here’s a Creative Way to Think About How Lens Apertures Physically Work

Photographer Nick de Bruijn came up with this really fun way to explain lens apertures to a friend.

When we think about all of the visual graphs in regards to how lens apertures work, there are literal drawings of them. But photographer Nick de Bruijn came up with a special way of explaining how they work simply by using and carefully arranging the lenses themselves. As you can in the image above, the lenses are arranged from top to bottom from 1.2 to f3.5. The way that one is supposed to think about this is the largest aperture is on top (and therefore less closed down) and then smallest is on the bottom. Of course, that all depends on the maximum aperture of the lens–but if you think about the size of this all being in regards to a single lens, then you’ll see how genius this all is.

Nick posted the image to Reddit, and explained that he used it as a way to get his friend to understand how an f stop works. The cool thing here is that these are all 50mm lenses with different maximum apertures. So of course, what it also means is that lenses that let in more light often need to be larger than an equivalent lens with a smaller aperture. All of this is based in part on the film plane/sensor size. For example, the size of an f2 lens on medium format is much different than it is on Micro Four Thirds.

“In a media Youtuber’s discord I run a “weekly” photo class, where it has become my goal to teach everyone, tech savvy or not, about photography.” says Nick to us in an interview. “Eventually I got the criticism that some parts did not translate well through text. That is when I started taking photos as examples.” According to Nick, telling someone that a lens aperture is the relation between the iris of the lens and the focal length goes over someone’s head–and we can totally understand why! That’s when Nick decided to actually show with the help of a photo how the lens elements become larger with smaller F-numhers at the same focal length.

Luckily, we were able to pull images from our database of reviews to help further visually illustrate this to you. Here’s what the depth of field looks like on 50mm lenses at these apertures.

f1.2

Canon RF 50mm f1.2 L USM at f1.2

f1.4

f2

ISO 100, 1/400th F2. This is an example of the Sun’s rays being lessened by cloud coverage

f3.5

As you can see, more and more of the subject comes into focus with less bokeh.

Nick isn’t really a big lens collector, but he rather does enjoy it. He uses a Sony A7 and claims that he bought three lenses, “out of necessity.”

My very first lenses for my digital camera were in fact vintage relics, because I lacked the budget for Sony lenses. A few months later I got my first analog camera, unfortunately the Helios-44-2 on it had some minor issues. This introduced me to CLA’ing my own lenses, here’s where it all took off. I started buying more and more old lenses and cameras online at ridiculously cheap prices, performing CLA on nearly every lens that I got. I stuck with the motto “I’ll sell to break even, the rest is my profit” now I own roughly 30 lenses of varying rarities, proudly sitting on my shelf, some with a body attached, others without.

For Nick, it’s difficult to name a single favorite lens, so he has three:

  • The first one would be the Carl Zeiss Flektogon 20mm F/4, mostly for its absurd front element that requires a 77mm filter thread. It also has ridiculously low distortion, which is amazing for a lens of that era.
  • My second favorite lens would be the Carl Zeiss “Olympia” sonnar 180mm F/2.8, the post war version with 18 blades. This lens looks amazing, performs quite amazingly and has a gorgeous tripod mount.
  • The last of my favorite would also be my most used lens, the Leica Summaron 35mm F2.8. this lens is easy to use, compact and performs so nicely. The size is what pulls it over the line for me, especially compared to other vintage and modern 35mm lenses.

Image by Nick de Bruijn. Used with explicit permission.