Polarization of light notes PDF

For this first set I'm sitting in the same location for each shot, just changing my lens to get the different focal lengths. Just scroll through to see each image or click on the thumbnail to get to the next image in the gallery.

Longer lengths, like the 135 or 200mm are obviously useful for when you are far away from your subject, or you want to narrow down your field of view, which can be great for keeping clutter out of the frame!  With that in mind, you can absolutely use a 200m indoors if you don't want to get too much of the surroundings in the scene - assuming of course you have the room to back up to use it!

Now, let's look at the same focal lengths again, but this time, I've tried to have Dave occupy the same amount of space in the frame for each one - this way you can see the difference in the final image depending on the lens you choose.

Polarized wavesin physics

Can you see the difference in the background with each one even through the subject is taking up the same amount of room in the frame? It's most obvious between 35 and 200mm.  That's lens compression in action!I

Circular polarization

No matter where light comes from, its polarization isn’t usually permanent. When light bounces off or passes through stuff, its polarization can meander, rotating a little or even flipping directions. For example, certain materials can block light with one polarization while letting another polarization through. If you’ve ever turned your head and caught the glare off a lake, you’ve seen a natural polarizer at work: The water reflects light that is polarized parallel to its surface, and when you turn your head in that precise direction, your eyes catch the glare. Ouch! Grab your polarized sunglasses to filter it out.

We are going to be comparing a multitude of lenses - the 35mm, 50mm, 85mm, 100mm, 135mm and 20mm focal lengths to be exact.

Polarization of electromagneticwavespdf

There’s nothing particularly quantum about polarization. However, light itself has a quantum side because in addition to being composed of waves, it can be described as indivisible bundles of energy called photons. These blips of light can be visualized as little waves that don’t extend over large distances. Each individual photon also has a polarization oriented this way or that.

Polarization usually depends on a wave’s origin story. The sunlight streaming toward Earth, which comes from the random fusion of nuclei in the sun’s core, is blasted out every which way in a mixture of polarizations. And the journey through the atmosphere doesn’t do anything to unscramble this mess. Scientists call this kind of disorganized light unpolarized. Energy-conserving LED lights also send out unpolarized light. Lasers, on the other hand, are a human-made source of polarized light.

Polarised wave definition a level

Scientists can make devices that emit photons one at a time, all with the same polarization. They can also use a combination of lenses (similar to those in eyeglasses), mirrors and crystals to manipulate and measure photon polarization. It turns out that polarization is one of the simplest properties of light to work with and so it is commonly used for storing a quantum bit, entangling photons and processing quantum information.

Polarizedand unpolarized light

So, each of these photos has been taken with a different lens, and therefore a different focal length,  so you can see how your field of view changes with each one.

This difference in how the scene looks (even if framed in the same way) is the reason why the workable distance from our subject is only one of our considerations when choosing which lens to use, as we will also want to think about what it does to the final look and feel of the image.  Lens compression deserves a whole post all of it's own, since it's a pretty important factor when choosing a lens, so I'll be back with more on that tomorrow!

Linear polarization

I gave up on trying to get someone to model for me - since one certain little boy wouldn't stay in the same place for long enough whilst I went through all my lenses (twice!) we have the lovely Dave as our model instead.

Don't forget to download your Which Lens Kickstarter Guide to get example images by focal length, along with your handy guide to which focal lengths are best of different types of images:

Types ofpolarized waves

Polarization describes the shape of a wave, regardless of whether it is traveling on water or as a vibration on a violin string. It answers a question like: Is the wave moving up and down or side to side? A buoy bobbing up and down in the wake of a boat is one signature of a wave that’s polarized up and down. And since “up” and “down” are connected by a straight line, this particular wave has linear polarization. Some waves can have more complicated shapes, too. For instance, light waves can travel through space like a corkscrew, which is an example of circular polarization.

This is why wide angles are great for landscapes, because you can fit so much of the scene in. They are also great for those times when you want to show more of your surroundings in lifestyle images, and - a plus point if you have little ones - they allow you to still be close to your subject, whilst still being able to get them in the frame.

I finally got around to photographing focal length comparisons again this week - I know these can be really helpful as a reference point so it's about time I got around to it!

I've also got a handy little guide for you that will be really helpful when considering which focal lengths might be useful for you - my which lens quick guide. It goes through different scenarios and which focal lengths will be ideal, along with example images from each focal length! Go here to get your copy!