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Guest Post: Four Tips for Taking Great Cloud Photos

Kevin Li took NATS 1780 two years ago. In addition to maintaining an interest in weather and climate, Kevin remains an accomplished and enthusiastic photographer. I asked Kevin if he might have a few cloud-photo tips to share with the students currently taking NATS 1780 at Toronto’s York University. Here’s his response:

Four Tips for Taking Great Cloud Photos:

  • It starts with composition of the photo (what you include in your photo, mostly clouds with some landscape or just clouds and the sky?) good composition will show us location, approximate time of the day, and weather conditions (which could explain why the shape of the clouds are the way they are)
  • Head out in the early morning around sunrise and around sunset. This will add some warm colours to your photos especially around sunset. You will notice that the clouds are more visible and distinct in those times of the day rather than mid-day
  • Focusing of the camera will be crucial and will depend on your camera. The focus should be placed on the cloud you want to photograph. This allows the camera to adjust the lighting to avoid over exposure and or under exposure
  • Lastly, if you are using a smartphone, your phone might have a feature that will boost the colour saturation levels. This feature will make some if your photos pop! For those with dslrs and point and shoot cameras, this can be done in post-production or maybe in-camera depending on the camera you have.

It’s not about the camera, but the person who is behind the camera! 🙂

Note for DSLR users only: A circular polarizer will help on those bright sunny days. If you don’t have one, use a high shutter speed or decrease the aperature size to f8 or smaller.

Many thanks to Kevin for sharing this excellent advice!

If you have additional tips to share, please feel free to add a comment. If you have a question, I’m sure I can persuade Kevin to answer it.

Current Events in the Classroom: Experiments on Mars-Like Clouds Stimulate the Learning Process

Everyone has an appreciation for humidity and clouds … However, when you seek to understand humidity and clouds from the scientific perspective, `things get technical‘ in a hurry! As someone who attempts to share science with non-scientists, it’s wonderful to be able to work current events into the (physical/virtual) classroom. Some recent experimental results, aimed at simulating Martian-style clouds, allow for a highly topical teachable moment.

For the details, please see below my recent post (via Moodle) to my Weather and Climate class at Toronto’s York University:


Now, if only I could have such a cloud chamber in the (virtual) classroom …

Pencasting During Lectures in Large Venues

In a recent post on pencasting as a way of teaching/learning weather and climate, I stated:

Monday (October 1, 2012), I intend to use a pencast during my lecture – to introduce aspects of the stability of Earth’s atmosphere. I’ll try to share here how it went. For this intended use of the pencast, I will use a landscape mode for presentation – as I expect that’ll work well in the large lecture hall I teach in. I am, however, a little concerned that the lines I’ll be drawing will be a little too thin/faint for the students at the back of the lecture theatre to see …

I followed through as advertized (above) earlier today.


My preliminary findings are as follows:

  • The visual aspects of the pencast are quite acceptable – This is true even in large lecture halls such as the 500-seat Price Family Cinema at York University (pictured above) in Toronto, Canada where I am currently teaching. I used landscape mode for today’s pencast, and zoomed it in a little. A slightly thicker pen option would be wonderful for such situations … as would different pen colours (the default is green).
  • The audio quality of the pencasts is very good to excellent – Although my Livescribe pen came with a headset/microphone, I don’t use it. I simply use the built-in microphone on the pen, and speak normally when I am developing pencasts. Of course, the audio capabilities of the lecture hall I teach in are most excellent for playback!
  • One-to-many live streaming of pencasts works well – I streamed live directly from myLivescibe today. I believe the application infrastructure is based largely on Adobe Flash and various Web services delivered by Web Objects. Regardless of the technical underpinnings, live streaming worked well. Of course, I could’ve developed a completely self-contained PDF file, downloaded this, and run the pencast locally using Adobe Reader.
  • Personal pencasting works well – I noticed that a number of students were streaming the pencast live for themselves during the lecture. In so doing, they could control interaction with the pencast.

Anecdotally, a few students mentioned that they appreciated the pencast during the break period – my class meets once per for a three-hour session.

Although I’ve yet to hear this feedback directly from the students, I believe I need to:

  • Decrease the duration of pencasts – Today’s lasts about 10 minutes
  • Employ a less-is-more approach/strategy – My pencasts are fairly involved when done …
  • Experiment with the right balance of speaking to penning (is that even a word!?) – Probably a less-is-more approach/strategy would work well here for both the penned and spoken word …

Finally, today’s pencast on the basics of atmospheric stability:

  • Previous approach – Project an illustration taken directly from the course’s text. This is a professionally produced, visually appealing, detailed, end-result, static diagram that I embedded in my presentation software (I use Google Docs for a number of reasons.) Using a laser pointer, my pedagogy called for a systematic deconstruction this diagram – hoping that the students would be engaged enough to actually follow me. Of course, in the captured versions of my lectures, the students don’t actually see where I’m directing the laser pointer. The students have access to the course text and my lecture slides. I have no idea if/how they attempt to ingest and learn from this approach.
  • Pencasting – As discussed elsewhere, the starting point is a blank slate. Using the pencasting technology, I sketch my own rendition of the illustration from the text. As I build up the details, I explain the concept of stability analyses. Because the sketch appears as I speak, the students have the potential to follow me quite closely – and if they miss anything, they can review the pencast after class at their own pace. The end result of a pencast is a sketch that doesn’t hold a candle to the professionally produced illustration provided in the text and my lecture notes. However, to evaluate the pencast as merely a final product, I believe, misses the point completely. Why? I believe the pencast is a far superior way to teach and to learn in situations such as this one. Why? I believe the pencast allows the teacher to focus on communication – communication that the learner can also choose to be highly receptive to, and engaged by.

I still regard myself as very much a neophyte in this arena. However, as the above final paragraphs indicate, pencasting is a disruptive innovation whose value in teaching/learning merits further investigation.

Teaching/Learning Weather and Climate via Pencasting

I first heard about it a few years ago, and thought it sounded interesting … and then, this past Summer, I did a little more research and decided to purchase a Livescribe 8 GB Echo(TM) Pro Pack. Over the Summer, I took notes with the pen from time-to-time and found it to be somewhat useful/interesting.

Just this week, however, I decided it was time to use the pen for the originally intended purpose: Making pencasts for the course I’m currently teaching in weather and climate at Toronto’s York University. Before I share some sample pencasts, please allow me to share my findings based on less than a week’s worth of `experience’:

  • Decent-quality pencasts can be produced with minimal effort – I figured out the basics (e.g., how to record my voice) in a few minutes, and started on my first pencast. Transferring the pencast from the pen to the desktop software to the Web (where it can be shared with my students) also requires minimal effort. “Decent quality” here refers to both the visual and audio elements. The fact that this is both a very natural (writing with a pen while speaking!) and speedy (efficient/effective) undertaking means that I am predisposed towards actually using the technology whenever it makes sense – more on that below. Net-net: This solution is teacher-friendly.
  • Pencasts compliment other instructional media – This is my current perspective … Pencasts compliment the textbook readings I assign, the lecture slides plus video/audio captures I provide, the Web sites we all share, the Moodle discussion forums we engage in, the Tweets I issue, etc. In the spirit of blended learning it is my hope that pencasts, in concert with these other instructional media, will allow my TAs and I to `reach’ most of the students in the course.
  • Pencasts allow the teacher to address both content and skills-oriented objectives – Up to this point, my pencasts have started from a blank page. This forces me to be focused, and systematically develop towards some desired content (e.g., conceptually introducing the phase diagram for H2O) and/or skills (e.g., how to calculate the slope of a line on a graph) oriented outcome. Because students can follow along, they have the opportunity to be fully engaged as the pencast progresses. Of course, what this also means is that this technology can be as effective in the first-year university level course I’m currently teaching, but also at the academic levels that precede (e.g., grade school, high school, etc.) and follow (senior undergraduate and graduate) this level.
  • Pencasts are learner-centric – In addition to be teacher-friendly, pencasts are learner-centric. Although a student could passively watch and listen to a pencast as it plays out in a linear, sequential fashion, the technology almost begs you to interact with it. As noted previously, this means a student can easily replay some aspect of the pencast that they missed. Even more interestingly, however, students can interact with pencasts in a random-access mode – a mode that would almost certainly be useful when they are attempting to apply the content/skills conveyed through the pencast to a tutorial or assignment they are working on, or a quiz or exam they are actively studying for. It is important to note that both the visual and audio elements of the pencast can be manipulated with impressive responsiveness to random-access input from the student.
  • I’m striving for authentic, not perfect pencasts – With a little more practice and some planning/scripting, I’d be willing to bet that I could produce an extremely polished pencast. Based on past experience teaching today’s first-year university students, I’m fairly convinced that this is something they couldn’t care less about. Let’s face it, my in-person lectures aren’t perfectly polished, and neither are my pencasts. Because I can easily go back to existing pencasts and add to them, I don’t need to fret too much about being perfect the first time. Too much time spent fussing here would diminish the natural and speedy aspects of the technology.

Findings aside, on to samples:

  • Calculating the lapse rate for Earth’s troposphere – This is a largely a skills-oriented example. It was my first pencast. I returned twice to the original pencast to make changes – once to correct a spelling mistake, and the second time to add in a bracket (“Run”) that I forgot. I communicated these changes to the students in the course via an updated link shared through a Moodle forum dedicated to pencasts. If you were to experience the updates, you’d almost be unaware of the lapse of time between the original pencast and the updates, as all of this is presented seamlessly as a single pencast to the students.
  • Introducing the pressure-temperature phase diagram for H2O – This is largely a content-oriented example. I got a little carried away in this one, and ended up packing in a little too much – the pencast is fairly long, and by the time I’m finished, the visual element is … a tad on the busy side. Experience gained.

Anecdotally, initial reaction from the students has been positive. Time will tell.

Next steps:

  • Monday (October 1, 2012), I intend to use a pencast during my lecture – to introduce aspects of the stability of Earth’s atmosphere. I’ll try to share here how it went. For this intended use of the pencast, I will use a landscape mode for presentation – as I expect that’ll work well in the large lecture hall I teach in. I am, however, a little concerned that the lines I’ll be drawing will be a little too thin/faint for the students at the back of the lecture theatre to see …
  • I have two sections of the NATS 1780 Weather and Climate course to teach this year. One section is taught the traditional way – almost 350 students in a large lecture theatre, 25-student tutorial groups, supported by Moodle, etc. In striking contrast to the approach taken in the meatspace section, is the second section where almost everything takes place online via Moodle. Although I have yet to support this hypothesis with any data, it is my belief that these pencasts are an excellent way to reach out to the students in the Internet-only section of the course. More on this over the fullness of time (i.e., the current academic session.)

Feel free to comment on this post or share your own experiences with pencasts.

Triple and Quadruple Rainbows: Theory Meets Practice

Last Fall 2010/Winter 2011, I taught the science of weather and climate to non-scientists at Toronto’s York University.

During the Fall semester, a unit of NATS 1780 focused on atmospheric optics. Not surprisingly, rainbows were one of the topics that received attention.

By the end of this unit, students understood that rainbows are the consequence of a twofold optical manipulation of sunlight:

  • Raindrops bend sunlight.  Not only do raindrops bend (refract) sunlight, they do so with extreme prejudice. Blue light gets bent the most, red the least. In other words, this is a wavelength-based prejudice: The shorter the wavelength, the more the light is bent. This highly selective refraction is known as dispersion. Like a prism then, raindrops allow for the individual colours that comprise visible light to be made evident.
  • Raindrops reflect sunlight.  Inside the raindrop, reflection occurs. In fact, multiple reflections can occur. And if all of the angles are just right, these reflections can remain contained within the raindrop. This is known as the phenomenon of Total Internal Reflection (TIR).
The combined effect of bending and internally reflecting is best understood with a diagram. Note in this Wikipedia diagram that sunlight interacts with the air/raindrop boundary upon entry, gets reflected internally once, and then again interacts with the raindrop/air boundary upon exit from the raindrop. Taken together, the result is a single rainbow.

How are double rainbows produced? By increasing the number of internal reflections to two.

Single and double rainbows are relatively easily observed.

On the Fall 2010 Exam in NATS 1780, I included the question:
If it were possible, how would a tertiary (i.e., third)
rainbow be produced?
A number of students correctly answered that three reflections internal to the raindrop would be required to produce such a phenomenon.

Although I had intended this to be a question of theoretical merit only, I was delighted to learn that both triple and quadruple rainbows have been observed – in other words, they are no longer just a theoretical possibility. (Quadruple rainbows would require four internal reflections.)

Alas, I’ve only ever been able to capture single and double rainbows … My personal quest for the more elusive triple and quadruple rainbows continues …