The Art & Science of Photomicrography with Polarized Light

by Dr. Robert Berdan
June 22, 2017

Pine wood by polarizing microscopy by Robert Berdan ©

Polarized light photomicrograph of Pine wood - showing the cells in the wood 400X

Many subjects when viewed through a microscope are unfamiliar and appear abstract. In this article I would like to share with you some pictures of crystals and other substances that bend polarized light (anisotropic substances). I believe these images are a true representation of abstract art. Abstract art uses a visual language to present concepts that may or may not reflect the real-world. Abstract art is intended to stimulate the mind of the viewer, question his or her perceptions as well as the visual representations he or she takes for granted (Artist.com Art Recognition and Education). I will provide some explanation about the science of how polarized light creates these colours and anyone with a simple microscope, polarizing filters and Scotch tape can produce abstract looking images. I sell these images as "Art" and can even create a unique set for you for a reasonable price form post card size up to several feet high. See my digital imaging prices or contact me for a custom quote. I can provide you with one off images that I will only sell to you. You may post these images on a web site or use them as screen savers for personal use. I only ask that you credit them and provide a link back to this article if posted on the web. If you are looking for images for commercial use e.g. make prints, clothing patterns etc. please contact me.

 

Abstract art - Citric acid crystals in polarized light by Robert Berdan ©

One of my favourite pictures of Citric Acid crystals in polarized light microscopy about 200X. The patterns remind me of multicoloured overlapping feathers.

First let me share with you some photo-micrographs of substances that bend polarized light. These substances are called birefringent and often have molecules arranged in a particular direction. Substances with strong birefringence (have two or more refractive indices) can produce colour when viewed through crossed polarizing filters. Substances that have weak birefringence can sometimes be enhanced using a wave plate or crystal wedge. You can make a wave plate by putting old fashioned scotch tape (not the white translucent tape that you can write on but the older clear-yellow tape) onto a glass slide to make a wave plate. By turning the specimen between polarized filters your can see different colours. Many substances like animal hair, potato starch, and crystals formed via evaporation can produce incredible patterns and colours - some of which I show below.

Abstract art - Citric acid crystals in polarized light by Robert Berdan ©

Citric Acid crystal polarized light microscopy 200X

Potassium Ferricyanide crystal in Poloarized light - abstract art by Robert Berdan  ©

Potassium Ferricyanide a chemical used in my old darkroom days for film processing - viewed in polarized light.

Wool fibers in polarized light abstract by Robert Berdan ©

Wool fibers in polarized light microscopy 100X

Potato starch grains in polarized light 100X - they behave like crystals  by Robert Berdan ©

Potato starch grains in polarized light 100X - they behave like crystals 150X

Potato starch grains in polarized light with an added full waveplate  - abstract art by Robert Berdan ©

Potato starch grains in polarized light with an added full waveplate which enhances the birefringence and adds colour - the colours depend on how the wave plate is rotated. Next time you eat a potato think about how beautiful the starch grains are. 200X

Potato starch grains in polarized light by Robert Berdan ©

Potato starch grains showing different coloured backgrounds as the wave plate is rotated in polarized light.

Bone cross section in polaized light microscopy  - abstract art by Robert Berdan ©

Bone cross section in polarized light microscopy 100X

Citric acid and caffeine crystals are two of my favourite crystals to examine with my microscope in polarized light. They form an endless pattern of interesting designs and colours - some are shown below. There is also a section of wood and several other chemical crystals.

Citric acid crystals in polarized light - abstract by Robert Berdan ©

Citric Acid Crystals in Polarized light - Abstract 100X

Citric acid crystals in polarized light - abstract by Robert Berdan ©

Citric Acid Crystals in Polarized light - Abstract 100X

Citic Acid Crystals in Polarized light - Abstract  by Robert Berdan

Citric Acid Crystals in Polarized light - Abstract 100X

Sodium Sulphite Crystals - Abstract by Robert Berdan ©

Sodium Sulphite Crystals - Abstract 50X

Citric Acid Crystals by polarized light microscopy - Abstract by Robert Berdan ©

Citric Acid Crystals by polarized light microscopy - Abstract by Robert Berdan 50X

Cross section of wood - White Pine - abstract by Polarized light microscopy - Abstract  by Robert Berdan ©

Cross section of wood - White Pine - abstract by Polarized light microscopy 100X

Lanthanum Chloride Crysals by Polarized light microscopy by Robert Berdan ©

Lanthanum Chloride Crystals by Polarized light microscopy 100X

Citric acid crystals by Polarized light microscopy - Abstract by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 200X

Citric acid crystals by Polarized light microscopy - Abstract by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 200X

Citric acid crystals by Polarized light microscopy - Abstract by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 100X

Citric acid crystals by Polarized light microscopy - Abstract art by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 50X

Citric acid crystals by Polarized light microscopy - Abstract art by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 200X

Citric acid crystals by Polarized light microscopy 100X  by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 100X

Citric acid crystals by Polarized light microscopy - Abstract art by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 100X

Citric acid crystals by Polarized light microscopy - Abstract Art by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 50X

Citric acid crystals by Polarized light microscopy - Abstract art by Robert Berdan ©

Citric acid crystals by Polarized light microscopy 200X

Citric acid crystals by Polarized light microscopy by Robert Berdan

Citric acid crystals by Polarized light microscopy 100X

Tylenol (Acetaminphen) Crystals by Polarized light microscopy - Abstract art by Robert Berdan ©

Tylenol (Acetaminophen) Crystals by Polarized light microscopy 100X

Potassium Ferricyanide crystals by Polarized light microscopy 100X

Of all the subjects I have photographed no other subject shows the saturation and variety of colours that I see when examining crystals and other birefringent specimens in a light microscope with polarized light. Below I describe how I make these crystals and a little about the science. For more in depth understanding of polarized light in crystals see some of my links and references.

The Science behind the pictures

Making the crystals is fairly easy, I start with different chemicals, some of them are household chemicals and medicines like Tylenol and I dissolve them into a test tube with water. I use a Vortex mixer to agitate the tube vigorously and try to produce a concentrated solution. I then place one or two drops on a microscope slide and allow the water (or sometimes alcohol) to evaporate. Heating the slides on a hot plate briefly can accelerate the process, but the slow evaporation method seems to produce the biggest and best crystals.

Above is a set of microscope slides I have covered with different crystalline solutions. After 10 min to several hours crystals will often form and then I can begin to look at them through my microscope equipped with a Polarizer (over the light source) and an analyzer ( another polarizer inside the eyepiece). I use wave plates to enhance the colour, a simple wave plate can be made by placing Scotch tape (old type) on a microscope slide.

Above I have two large polarizing sheets which are crossed and block light where they overlap. Some crystals like the Mica crystal placed between the polarizers "bend" the polarized light so that the polarized light undergoes interference and certain colours (wavelengths) are omitted by destructive interference. The colours depend on the refractive index of the crystal and the thickness which is why you are looking at different colours in this large crystal. The same process occurs in a light microscope, but the crystal are of course much smaller.

Above I placed a microscope slide between the polarizers on my photography light box - you can see some of the colours in the citric acid crystals. When viewed in a light microscope you will see pictures like those I show above. Usually only 4X, 10X, or 20X objective are required and almost any light microscope can be used. For really large crystals you could use a macro lens like I have above.

Above I placed two microscope slides side by side between the crossed polarizers. On the top slide I layered Scotch tape in different thicknesses - you can see different interference colours. As the tape gets thicker, the colours get fainter and more subdued. They become 2nd, 3rd or 4th order interference colours. On the slide below I placed several pieces of Scotch tape at right angles on top of each other. Note the black cross - these are the same ones I show above on the potato starch grains, but starch grains are not flat so the cross is bent in places. To understand the physics behind the interference see some of my links and books below and watch some of the YouTube videos.

A feature found on microscopes specialized for polarized light microscopy and examination of minerals is a Bertrand lens (Sometimes called Amici-Bertrand lens) which sits between the eyepice and objective turret. The interference pattern can also be seen on any microscope with polarization filters by removing the eyepiece and looking down the tube or one can also use a Phase telescope. You need to use a high magnification objective e.g. 40X-60X and when the Bertran lens is inserted into light path it allows one to see an interference pattern (show below) which can be used to determine if the crystal is uniaxial or biaxial. I found it works well when you have a single mineral e.g. Mica (Muscovite) but not so well in mineral sections with many different types of components. I will have more on this in a future article.

Mica (Muscovite) Biaxial interference pattern viewed in a Unitron Polarizing microscope, 40X objective by Robert Berdan ©

Mica (Muscovite) Biaxial interference pattern viewed in a Unitron Polarizing microscope, 40X objective.

Above are some of my microscopes Left: stereo microscope (5-50X), Next to it is a Canon 5D Mark II camera with MP-E 65 mm Macro lens (1-5X), in the middle Nikon Optiphot microscope (40X-1000X), and on the right my old Olympus-E microscope (10X-1000X). I attach Nikon and Canon cameras to the top of the binocular head, and capture the images to my laptop using free software called Digicam control. My RAW images are processed in Adobe Photoshop CC2017. A used microscope can be purchased on Kijjii and E-bay for reasonable prices starting at about $50 and up.

I hope you find the colours, shapes and forms stimulating and if you own a microscope try viewing some crystals with polarized light and also look at many other biological specimens. If you have any questions about the photos or using a polarizing microscope feel free to send me an email. If you are interested in learning how to take such pictures I also offer training in my home laboratory and I am offering workshops on microscopy for thos interested. RB

Relevant Links

Historical Giants of Abstract Art - Artist.com
Abstract Art - Wikipedia
The Amateur Scientist, December 1977 - Studying Polarized Light
What you ought to know about Polarizing Light Microscopy
Elizabeth A. Wood (1977) Crystals and Light - An Introduction to Optical Crystallography
Digicam control software free for PC supports most Nikon and Canon cameras
Introduction to polarized light microscopy by Nikon
Circular Polarized light - Wikipedia
Birefringence - Wikipedia
Olympus microscope - Michel-Levy Birfringence Chart - used to identify refractive indices
Michel-Levy Interference Colour Chart - Gustav Delly
Michel-Levy Interference Colour Chart from Zeiss - high quality PDF

"We found these cool gift ideas for photographers on Look Whats Cool."

Recommended YoutubeVideos on Polarized Light microscopy

German Photographer Manfred Kage and his Photomicrographic Art Work
TrifidStudio How 2 Photomicrography - shows you how to make a DSLR microscope adapter from a lens cap
Earth Optics 1 - Polarized light microscopy of minerals
Earth Optics 2 - Cross Polarized Light of minerals
Earth Optics 3 - Fast and Slow rays determine with polarized light
Earth Optics 4 - Petrology - how to determine whether a mineral is postive or negative
Earth Optics 5 - flash figures of crystals
Earth Optics 6 - Biaxial Minerals in Polarized light
Earth Optics 7 - Biaxial Flash Figures
Minerals and Light - lecture

Also see my other photo-micrography articles:

Photographing Through a Microscope Photomicrography - Inner Space
Microscopic Life in Ponds and Rainwater
Taking Pictures with a Microscope reveals Invisible Worlds
Photomicrography Gallery

 

Authors Biography & Contact Information

Portrait of Robert Berdan

Robert Berdan is a professional nature photographer living in Calgary, AB specializing in nature, wildlife and science photography. Robert offers photo guiding and private instruction in all aspects of nature photography and Adobe Photoshop training.

Email at: rberdan@scienceandart.org
Web site: www.canadiannaturephotographer.com
Phone: MST 9am -7 pm (403) 247-2457.

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