Effect of a polarizer on a rainbow - interesting results

Above:  Rainbow I photographed today while visiting Waterton National Park - no polarizer used.
Below:  The same rainbow, but the polarizer took the polarized light away, making it almost vanish.
 

We have been at Waterton now for 4 days and have one day left.  I like to get moving early in the morning because the light is usually better and there are less people about to get in the way.  We were heading to Red Rock Canyon to photograph the gorge when a rainbow appeared ahead of us.  It was a pretty good one and I pulled over right away to photograph it.

I have shot numerous rainbows, but have never had a polarizer with me and I used it for the second photo.  The rainbow magically disappeared, or nearly, and only a trace of it was left.  This, of course, is something you don't want to do when photographing one, but I was curious what the result would be.

It turns out that rainbows are caused by polarized light.  In order to have a rainbow you need sunshine passing through falling rain.  The spherical shape of the raindrops causes the light to be refracted.  The brightness of the rainbow is based upon the angle of the sun (lower angles are better), the size of the raindrops (larger drops are better), and the sun being at full brightness.  The light refracts going through the droplets and becomes polarized.  

The polarizer negated the polarized light - but not all of it.  By rotating the polarizer I could alter which parts of the rainbow disappeared.  Although all of the rainbow was polarized, the angle of polarization was not the same for the entire thing and thus the polarizer affected only part of it.  Isn't that interesting?

Thanks for reading.

Eric Svendsen     www.ericspix.com

Comments

Post a Comment

Popular posts from this blog

Harjit Bahia - Science teacher and colleague from Garibaldi died August 2, 2024

Image
You will be missed Mr. Bahia.  You made a difference and we are sad you are gone. I keep in loose contact with my fellow retired teachers from Garibaldi Secondary School.  I talked with my long-time friend, Mike Lynch, today, and discovered that Hargit died over the summer.  Unbeknownst to him, he had an underlying heart condition and passed away after working out on his treadmill.  The date was August 2, 2024. I was shocked to hear this.  He was only 49 years old, turning 50 some 3 months later.  It was a shock to everyone, for he was loved by all who knew him.  As a teacher, Mr. Bahia was kind and fun.  He contributed to students in many ways and was always available to help those in need.   For myself, I knew him as a fellow science teacher and taught in the adjoining room to him.  He was always available to help, share ideas, and work together.  Easy to approach, I found that I could talk to him about anything and appreciat...
Read more

I found a black widow spider in a plant pot today

Image
The spider I found is a western black widow spider, one of three species of black widow that occur in North America.  The fact that this one has another red patch on the back of its abdomen above the spinnerettes tells us that it is an immature individual. The one thing that people know about black widow spiders is that they are extremely poisonous.  Their venom is something like 15x more toxic than that of a rattlesnake.  The saving grace is that there is very little venom injected from a black widow bite than what a rattlesnake can deliver.   The good news is that black widow bites seldom lead to death.  You are more likely to suffer nausea, muscle pain, and swelling around the bite.  Symptoms usually last only 12 hours or so.  Death may be a result in people with compromised immune systems or in the very young or the elderly.   In 2018, it was reported that there were 1015 cases of people bitten by black widows.  Of those, there ...
Read more

Mountain Bluebird - out of the blue.

Image
Mountain Bluebird photographed near Princeton, BC. While camping at a resort near Princeton, BC, I had a chance to visit a wildlife refuge that was nearby.  There are about 5 km of trails there and it took me two days to cover them all.  That may sound like an unreasonably slow rate of progression, but I took several hundred images during my time there and did a fair amount of step retracing.  The end result was the opportunity to get some great hiking in and see three bird species I have never encountered before. On the first day, I saw and photographed a pygmy nuthatch.  I have seen the white-breasted and red-breasted varieties but never this species.  The second day caught me completely off guard, as within the span of 30 seconds I saw the other two, a Bullock's oriole and a mountain bluebird.  It was a stunning discovery, for me anyway, and I can still feel the thrill of the moment thinking back on it.  Many of you may think this a bit odd, t...
Read more