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Josh Johnson
Touring theatre and Mac technician
Touring theatre and Mac technician

Josh's posts

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REQUIRED READING! Finally somebody articulates what I have been feeling for years:

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We live in the future:

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Fun with Google Photos!
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Gorgeous! He (she? It?) looks like a Doctor Who monster. 
How To Make an Award Winning Image Using a Scanning Electron Microscope

Recently the 14th Wellcome Image Awards were presented on 18 March 2015, recognizing the creators of the most informative, striking and technically excellent images recently acquired by Wellcome Images, as chosen by a panel of judges.  Welcome Images is a leading resource for medical imagery funded the Welcome Trust.  ⓐ

Wellcome Trust is a global charitable foundation dedicated to improving health by supporting bright minds in science, the humanities and social sciences, and public engagement.  ⓑ

I recommend going over to the image awards site and looking at all of them.  They are striking and beautiful as well as full of wonderful science. 

I was particularly taken by the image of the boll weevil, the image you see below.  It was taken by Daniel Kariko with a Scanning Electron Microscope (SEM) and enhanced using colors and textures from a series of images taken with a stereo microscope.  Be sure you look at this in full screen, it is a high resolution image. 

A light microscope focuses visible light, while a SEM uses a beam of electrons scanned back and forth over the specimen and the results are analyzed by an electron detector rather than the human eye. 

Light microscopes are limited by the wavelength of light to a maximum resolution of about 200 nm and have a limited depth of field.

A SEM is much better than a light microscope in resolution and depth of field, as well as the ability to perform microanalysis of the sample.

The scanning electron microscope (SEM) provides the competent user with an advantage over the light microscope (LM) in three key areas:  ⓒ

Resolution at high magnification. Resolution can be defined as the least distance between two closely opposed points, at which they may be recognized as two separate entities. The best resolution possible in a LM is about 200 nm whereas a typical SEM has a resolution of better than 10 nm (typically 5 nm).  ⓒ

Depth of field i.e. the height of a specimen that appears in focus in an image - more than 300 times the depth of field compared to the LM. This means that great topographical detail can be obtained. For many users, the three dimensional (3D) appearance of the specimen image, is the most valuable feature of the SEM. This is because such images, even at low magnifications, can provide much more information about a specimen than is available using the LM. The use of "stereo pair" SEM images can give even greater information about the sample.  ⓒ

Microanalysis i.e. the analysis of sample composition including information about chemical composition, as well as crystallographic, magnetic and electrical characteristics.  ⓒ    

One drawback to the use of the SEM is that it operates under vacuum and in many SEMs the samples must be rendered conductive to be viewed. This is often achieved by coating with a very thin layer of metal or carbon.  ⓒ  Also an SEM image is rendered in black and white and has to be manually colorized to include any colors.  SEM’s do not ‘see’ color.  So how did Daniel Kariko get that beautiful color image of the boll weevil below?

From the description of how he took the image:
“The images start as colour digital files from a stereoscope light microscope,” explains Daniel. “I carefully arrange LED lighting, small reflectors and diffusers, in order to achieve a portrait-like effect. Next, the same area of the specimen is imaged with a scanning electron microscope (SEM) because this microscope has much greater depth of field and thus increased sharpness for the entire specimen. In the end, I composite the colour images from the stereo microscope with the monochromatic images from the SEM to complete the portrait, therefore combining realistic colour with the detail of electron microscope imaging.”  ⓓ

So next time you see a beautiful color image taken with a SEM, remember how much work it took to turn a B/W image into award winning color.

ⓐ  Wellcome Images Awards 2015

ⓑ  Wellcome Trust

ⓒ  Australian Microscopy and Microanalysis Research Facility (AMMRF)
Background information - What is scanning electron microscopy?

ⓓ  Boll Weevil Image by Daniel Kariko

Tip of the hat to +Amanda Rachelle Warren  for finding this image. 

 Image: Daniel Kariko
Scanning electron microscope composite image of the head of a boll weevil (Anthonomus grandis) found on the front porch of a suburban house. The boll weevil is a beetle that feeds on and lays its eggs in the cotton plant. These agricultural pests have long curved snouts (often half as long as their bodies) and can destroy entire cotton crops. They develop from egg to adult in approximately 20 days and grow on average to 6–8 mm in length. This is one image in a series of work looking at common household pests found inside homes on the outskirts of town. These images of our often-overlooked housemates are in the style of traditional portraits. The width of the image is 4.1 mm  

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One more reason to use an alphanumeric password on your iPhone (NOT a 4-digit pin!)

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A good summary of the current state of communications security, and what led up to this:
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