As humans, we all see light differently, Yesterday, I watched a painter share paint swatches with a client in a coffee shop. He called out the colours of the swatches and she disagreed with him on almost every single swatch. He was reading the labels, she was looking at the colours. They saw completely different colours. He showed her a pure brown swatch and she said it was greenish, not brown. They were at an impasse and she flatly refused to agree on even a single colour. Why?
Scientists think that other factors, such as mood, feelings, and even memories can affect our perception of colours. They claim it is entirely possible that two people can look at the same object and have the same wavelengths hit their eyes, yet “see” different colors!
There’s a scientific explanation for why The Dress looks black and blue to some people and white and gold to the others. (But seriously, it looks white and gold, am I Right?)
Although your eyes perceive colours differently based on colour perceptors in them called cones, experts say your brain is doing the legwork to determine what you’re seeing – and it gets most of the blame for your heated debates about The Dress.
Our brain basically biases certain colours depending on what time of day it is, what the surrounding light conditions are, etc. So this is a filtering process by the brain. Objects appear reddish at dawn and dusk, but they appear blueish in the middle of the day. So we can recognize the same objects in different light conditions, our brains tweak the way we see things. The brain is very good at adjusting and calibrating so you perceive light conditions as constant even though they vary widely.
Because light travels so fast – 299,792,458 metres per second – it can trip over itself. Light can be clumsy.
Do you realize that different media share similar characteristics? A lens and a satellite antenna are technically similar, but operate at different frequencies. Even many of the terms used to describe these two disparate technologies are exactly the same and mean the same thing. For example, F/D ratio described the focal length to diameter ratio. It is a shared measurement for both camera lenses and satellite antennas. So, there is a significant crossover of technology between technologies and even between the way that humans work and how technology works. If you comprehend one idea, you can easily extend it to other media and systems. Here is a wonderful example of just such a transference.
Man Versus Machine
The world of technology does not have a brain to compensate for actual, physical colour variation.
There are many technical factors that can cause colours to vary beyond the subjective process from the eyes to the brain. The transmission of light as it passes through media, such as glass in lenses, is very tricky.
For example, in optics, lenses can show problems related to what is called, chromatic aberration. Now Nikon has solved this problem.
This new lens manages to attain its comparatively small size and light weight for two reasons. First, it is an f/5.6 rather than f/4, which certainly helps. Second, it uses a Phase Fresnel (PF) lens element, a specialized element that allows Nikon to replace multiple standard lens elements with one that is smaller and thinner. The result is a 500mm lens that, by all indications, will be easier to handhold than any other 500mm lens Nikon has ever released. (Even the Nikon 200-500mm f/5.6 weighs an additional 840 grams/1.85 pounds.)
Along with the PF element, this lens also has a fluorine coat on the front lens surface, which helps repel water beads on the surface, as well as making it easier to keep the lens clean. The 500mm f/5.6 PF also has an electromagnetic diaphragm, which we have only started to see in Nikon’s new lens releases recently (mainly super-telephotos, but also the 28mm f/1.4E). The 500mm f/5.6 has a 1:5.5 reproduction ratio as well, which is very close focus.
The 500mm f/5.6E PF has 19 elements in 11 groups, including three ED lens elements along with the PF element and fluorine coat. Here is a lens diagram provided by Nikon:
Phase Fresnel Technology
For nearly two centuries, Fresnel lenses were used in lighthouses to project a strong beam of light. By harnessing the idea in reverse – for gathering light instead of projecting it – Nikon engineers have created lenses that are shorter and lighter, with the same image quality and zoom power of much larger lenses. I own the new 500mm and the other model with this technology, the 300mm, too. These lenses are ideal for my airshow photography. I marvel at the ingenuity of the Nikon engineers to solve this light and colour transmission problem.
Normally, I think of the world of physics – the world of physical designs – as fixed and finite, since physics do not change for anyone. Yet, it astounds me when I see solutions like Nikon’s Phased Fresnel technology defy logic and seemingly change the rules of physics. Of course, they are not affecting the laws of physics, they have just been innovative and discovered a way to work around the problems. It is most fun when engineers like Nikon make use of technology that is hundreds of years old to solve modern day problems.
The PF (Phase Fresnel) lens, developed by Nikon, effectively compensates chromatic aberration utilizing the photo diffraction phenomenon*. It provides superior chromatic aberration compensation performance when combined with a normal glass lens. Compared to many general camera lenses that employ an optical system using the photo-refractive phenomenon, a remarkably compact and lightweight body can be attained with less number of lens elements.
A general interchangeable lens forms an image on an imaging plane, using the photo-refractive phenomenon. The degree of light refraction differs depending on the colour (wavelength), and image formation is performed in the order of blue (B), green (G), and red (R) starting with the portion near the lens (see the diagram below). The colour deviation referred to as chromatic aberration induces colour bleeding, resulting in a deterioration of observed or captured images.
With PF (Phase Fresnel) lenses, on the other hand, image formation is performed in the order of red (R), green (G), and blue (B) starting with the portion near the lens (see the diagram below). By combining the PF (Phase Fresnel) lens with a refractive lens, chromatic aberration can be effectively compensated.
By using Fresnel elements in the lens design, Nikon was effectively able to compensate for the speed of light differences found in the different wavelengths between 400nm to 750nm – the visible spectrum.
* Diffraction phenomenon: Light has characteristics as a waveform. When a waveform faces an obstacle, it attempts to go around and behind it, and this characteristic is referred to as diffraction. Diffraction causes chromatic dispersion in the reverse order of refraction.
Therefore, the colour of light is the biggest hurtle to overcome. The perception of colour is heavily influenced by the media and how light interacts with the media. So, just like the woman arguing with the painter as to which colour was brown versus which colour is green, light is highly subjective and greatly influenced by our environment.
Cox, S. (2018). Nikon 500mm f/5.6E PF Lens Announcement. Photography Life. Retrieved on December 22, 2018 from, https://photographylife.com/news/nikon-500mm-f-5-6e-pf-lens-announcement
Lupkin, S. (2015). White And Gold Or Black And Blue: Why People See the Dress Differently. ABC News. Retrieved on December 22, 2018 from, https://abcnews.go.com/Health/dress-people-viral-outfit-colors-differently/story?id=29268831
Nikon. (2018). AF-S Nikkor 500mm f.5.6E PF ED VR. Nikon Canada Inc. Retrieved on December 22, 2018 from, https://en.nikon.ca/nikon-products/product/camera-lenses/af-s-nikkor-500mm-f%252f5.6e-pf-ed-vr.html
Nikon Rumours. (2015). Nikon’s Phase Fresnel (PF) Lens Explained. Nikonrumours.com. Retrieved on December 22, 2018 from, https://nikonrumors.com/2015/01/06/nikons-phase-fresnel-pf-lens-explained.aspx/
About the Author:
Michael Martin has more than 35 years of experience in systems design for broadband networks, optical fibre, wireless and digital communications technologies.
He is a Senior Executive with IBM Canada’s GTS Network Services Group. Over the past 13 years with IBM, he has worked in the GBS Global Center of Competency for Energy and Utilities and the GTS Global Center of Excellence for Energy and Utilities. He was previously a founding partner and President of MICAN Communications and before that was President of Comlink Systems Limited and Ensat Broadcast Services, Inc., both divisions of Cygnal Technologies Corporation (CYN: TSX).
Martin currently serves on the Board of Directors for TeraGo Inc (TGO: TSX) and previously served on the Board of Directors for Avante Logixx Inc. (XX: TSX.V).
He serves as a Member, SCC ISO-IEC JTC 1/SC-41 – Internet of Things and related technologies, ISO – International Organization for Standardization, and as a member of the NIST SP 500-325 Fog Computing Conceptual Model, National Institute of Standards and Technology.
He served on the Board of Governors of the University of Ontario Institute of Technology (UOIT) and on the Board of Advisers of five different Colleges in Ontario. For 16 years he served on the Board of the Society of Motion Picture and Television Engineers (SMPTE), Toronto Section.
He holds three master’s degrees, in business (MBA), communication (MA), and education (MEd). As well, he has diplomas and certifications in business, computer programming, internetworking, project management, media, photography, and communication technology.