International Colour Vision Society Meeting 2019

Written by Ruben Pastilha

The International Colour Vision Society (ICVS) is an international group of physiologists, psychologists, physicists, geneticists, optometrists, ophthalmologists and visual scientists who have a research interest in the many aspects of colour vision and colour vision deficiencies.

Ruben Pastilha presenting his paper at the ICVS 2019

This years meeting was held in Riga, Latvia and I have been fortunate enough to win the runner-up Talk Prize.

I presented my paper on The Temporal Dynamics of Daylight: Speed Limits on Perception. Relatively little is known about human sensitivity to changes in illumination spectra over time. We have been interested in the temporal dynamics and speed limits of illumination change perception, in particular, for daylight changes. People are aware that outdoor illumination varies in chromaticity throughout the day, yet we don’t seem to directly perceive these changes while they occur. Using psychophysical testing with daylight metamers in an immersive illumination setting we found that, for 21 participants, the minimum detectable speed of chromaticity change is on average about 20 times larger than the fastest changes usually occurring in natural daylight. In addition, we found that changes in illumination chromaticity towards a neutral reference are hardest to detect, for non-neutral adaptation lights. This supports the notion that the brain encodes a neutral-daylight illumination prior.

Ruben presenting at ICVS 2019

The daily life of museum secondment – part 2

Written by Ellen De Korte

It is roughly one week until the Lates and the Bradford Science Festival. I am collecting final bits for my stall and testing things out. The big challenge of it all is finding ways to draw people in and keep them long enough in order to get them interested in my research. This is not only about designing my stall, but also how I will take visitors through my objects.

Cameras from the National Science and Media Museum’s handling collection were a major challenge, because they appeared to be more attractive to visitors than the other ordinary objects on my table. It is interesting to see people’s responses to the cameras. Visitors seemed to find cameras from around 1900 strange (and they are), because taking a picture with it is very different from how we take pictures nowadays. On the other hand, the more recent ones (1980’s) were more familiar to older visitors, so the cameras draw people in for two entirely opposing reasons.

Either way, this meant that I had to find a way to get the handling collections objects in, without entirely losing the visitors to them. As soon as visitors were allowed to handle the old cameras, it was hard to get them back on track. Therefore, I tried introducing the cameras later on as a surprise for visitors who lingered a bit longer, which seemed to work much better.

This is one of the many things I am learning on my way to the Lates and the Bradford Science Festival. I think I will learn a lot during the events themselves as well. For now, I will get ready for the big days and enjoy a visit to the museum’s partner in Manchester: the National Science and Industry Museum.

The daily life of museum secondment – part 1

Written by Ellen De Korte

It is two more weeks until the Bradford Science Festival. My collection of objects is now complete and the preparation of my text and study material is almost done. In the meantime, I have also become a STEM-ambassador. STEM is an acronym for the combined subjects of Science Technology Engineering and Mathematics. A STEM-ambassador is a volunteer who promotes those subjects in various ways. This can include demonstrations at schools, but it means you can also work with teachers in promoting STEM in schools.

As my research topic is part of psychology, it may seem a bit odd that I have become a STEM-ambassador. Yet, there is quite a bit of STEM involved in my job. For example, if I set up a typical experiment, I have to display the materials I want to show on a computer. Not only is the computer itself an obvious piece of STEM, but the images of materials involve quite a bit of mathematics. For a computer an image is a big table of numbers that represent image colours. Unfortunately, computer monitors do not always display the right colour if you give them a specific number. This means that I have to check the colours that my monitor displays with a special device. On top of that, I have to pay attention to the lighting of the materials I use, because this influences the look of materials as well. These little things involve physics and mathematics (light and the transformation of numbers in light to get colours) and this is not even the data collection and analysis yet (there is a lot of mathematics involved in the latter).

I will not bother you any further with the biology that is involved in my subject, because I have to understand the workings of the eye and the brain as well. Or how our research findings might be used for design of materials (engineering). All I hope, is that it has become clear that STEM is a big part of my job and our daily lives.  

A Study in Gloss

Secondment review by Sina Mehraeen

One’s ideas must be as broad as Nature if they are to interpret Nature
                                                                                     ― Arthur Conan Doyle

Here are the chronicles of my adventures during my secondment at the Department of Psychology, University of Southampton, under the supervision of Prof. Wendy Adams and Prof. Marc Ernst.

The Objectives of the trip:

  1. Gain an understanding of the interaction between illumination and material perception, including analysis of spherical high dynamic range natural illumination environments.
  2. Gain experience of working in a Psychology department in another EU country.

To begin at the beginning, I was excited to work with Wendy and to be exposed to the cool research she does on material perception, illumination environments and rendering virtual objects.  I had also never been to the UK, and was eager to get a glimpse of that part of the world.

The plan was twofold; first, I would conduct a pilot study on the interaction between illumination and gloss and how gloss might affect the way we manipulate a physical object. At the same time, I would try to learn as much as possible on rendering virtual objects in natural illumination environments and learn the statistics involved.

Sample HDR illumination environment sourced from the Southampton-York Natural Scenes (SYNS) Dataset. The SYNS dataset is a collection of high definition images (and their relevant metadata) from around 100 rural and urban locations.

After a short trip to a metal supermarket, we got some nice aluminum box pipes which we would use as our physical stimuli. The main question we were seeking to address with these physical objects is whether their glossiness affects the way people handle them. This is in line with previous studies looking at the relationship between gloss and touch (Kerrigan, Adams, & Graf, 2010 ; Adams, Kerrigan & Graf, 2016).

Aluminum box pipe

Once the objects were cleaned and nicely polished, we started testing out a suitable experimental setup. This proved more challenging than expected due to the unpredictable nature of natural lighting. In order to get the desired outcome, we really had to control the angle and intensity of illumination so using natural lighting was out of the question. We also tested various coatings to get the objects to be as glossy as possible. Currently, we have made some tweaks to the set up and we are in the process of data collection; so more info coming soon.

On the side and as a secondary objective, I began learning the basics of Blender to generate virtual objects and to import them as .obj files into Octane Render. Octane is fast rendering engine which allows for easy manipulation of minute elements which make up a scene, e.g. material qualities an object might possess and how those certain qualities (e.g. surface reflectance) interact with light. Once we had set those parameters, we placed them in a natural illumination environment and got something that looked like this:

A virtual object placed in a natural illumination environment

To conclude, I’d like to thank Wendy, Marc and Erich for their continuous support during my stay and also Davide and Paul for helping me with the setup. I’d also like to say a big thanks to everyone I had the good fortune of meeting at the Department of Psychology in Soton; for showing me around town and volunteering to participate in the experiment. Looking forward to seeing you all again soon.

Cheerio!

Secondment at the Science and Media Museum

Secondment at the Science and Media Museum

By Ellen De Korte

It has been four weeks since I started my museum secondment at the National Science and Media Museum and there are three more weeks to go until the Bradford Science Festival. I am busy preparing all text and materials for my study. However, the most exciting bit is that I am now testing objects that I have collected from charity shops and colleagues. This resulted in interesting responses. Also, the visitors are happy to try the task that is part of my activity. The next stage is to get everything ready, test the entire activity and pilot data collection.

How do I feel about public engagement? I found that it is one thing to learn to do science and an entirely different thing to communicate about it. Explainers in the museum seem to do it with ease. However, when I tried to do it myself, I found that it is a lot harder than it looks. For example, you have to learn how to get people interested in what you are doing. Moreover, you need to constantly switch gears, because you encounter people from different backgrounds.

Nevertheless, if you manage to draw people in and interact with them, it is a rewarding experience. People are willing to listen and take a little piece of information with them. Also, the skills you learn when doing science communication can be transferred to communicating your work to a specialist audience. Communication to a non-specialist audience teaches you how to quickly pitch and sell your work in simple wording. The pitching and selling skills are very useful for presentations, for example at a conference, too, because this also requires you to shortly pitch your work to people passing by.

All in all, my museum secondment is an entirely different experience. However, it is also an interesting challenge, from which I will have learnt a lot at the end.