Background
I set up my Scanning Electron Microscope (SEM) facility in early 2016 with three objectives in mind. These are:
- To understand the physics and engineering behind the SEM.
- To advance my interest in arachnology by studying and imaging spiders and other arachnids in detail not obtainable by conventional light microscopy.
- To create attractive artwork from images of subjects of all types using the SEM.
Since then I have created thousands of images of many subjects, working alone and also in collaboration with friends from the various microscopical and other relevant societies of which I am a member. In 2021 I was awarded the distinction of Fellow of the Royal Photographic Society for a book of Pictures created using my SEM.
What is an SEM?
An SEM is an instrument that is capable of providing highly magnified images of a specimen placed in the chamber of the microscope. Subjects may be biological, which is the type of subject I usually image, or more relevant to materials science or physics.
The SEM uses a beam of electrons to create the image of the specimen, rather than light as is used in conventional microscopy. The electron beam is scanned across the surface of the object and electrons released at the surface of the specimen by the interaction of the beam and the specimen are detected and used to create an image of the specimen’s surface. While an SEM is capable of producing much higher magnifications than light microscopy, or to be more precise, much higher resolutions, it is often used at magnifications of between x50 and x1,000 because it gives a much greater depth of field than is possible with a light microscope, as is illustrated below. Among the disadvantages of an SEM over a light microscope are the fact that an SEM is many times more expensive than a conventional light microscope and also, the image does not contain any colour information. Furthermore, it is necessary to dry the specimen without deforming it and then to coat it with a very thin layer of gold or similar conducting material before placing it in the chamber of the SEM.
About this Site
The site consists of the following pages, which can be accessed using the navigation bar at the top of each page or the links below:
- The home page.
- An Introduction (this page).
- A brief description and specification of my SEM. Go
- A similarly brief guided tour of my laboratory, including photos of the specimen preparation equipment. Go
- A description of my previous SEM, which occupied the lab from January 2016 to June 2020. (This page is not included on the navigation bar.) Go
- Galleries of electron micrographs. Subjects include foraminifera, diatoms and similar material together with parts of spiders, ticks and insects, among others. There are two gallery pages. The main gallery page is of images created using the TESCAN MIRA. Go
Earlier images made using my FEI Inspect SEM may also be viewed. Go
- A page for contact information and external links, together with a short biography. Go
- SEM Diaries. A series of articles for Balsam Post, the Newsletter of the Postal Microscopical Society, recording progress with the project. Go
- Last, but by no means least, there is now a sub-
domain devoted to electron micrographs of key features of British spiders. This can be accessed from the bottom right button on the navigation bar at the top of this page. (Opens in new window.)
Introduction
Illustrating the difference of depth of field between an image from a conventional light microscope (left) and a scanning electron microscope (right). In the left hand image only a small fraction of the micro-