When you call up a major university and ask to use their research-grade electron microscope, they naturally assume you have a high-minded scientific purpose. Perhaps you're analyzing the microstructure of a nanomaterial? Performing a metallurgical study on a precision machine part? Analyzing the morphology of a new species of fungus? When you tell them your goal is "taking pretty pictures of plants and such", they're not quite sure how to react.
Let me explain. My company, Gado Images, works with archives worldwide to help them digitize and share their visual history. That means we do a lot of work with textbook publishers; these publishers often need high-quality historical photos to illustrate their books. But the same people who need historical photos of smallpox eradication, iron lungs, and the like often need contemporary images to illustrate scientific concepts, too.
Scientists use an electron microscope ca 1980 /DOE/Gado
In particular, they often want electron microscope images. We receive so many requests for these kinds of images that we eventually decided to go ahead and create them ourselves. Thus the calls to local universities, and the confused research scientists. Somewhat surprisingly, we eventually found a university which agreed to let us use their scanning electron microscope.
Electron microscopes are very much like cameras. Just as a camera captures light from a scene in order to make a picture, an electron microscope shoots electrons (tiny charged particles) at an object, and then creates an image based on the ones which bounce back. The difference is that electrons have a smaller wavelength than visible light; much smaller. This means you can use them to take much more detailed pictures of an object. Just as cramming more pixels onto a DSLR's sensor lets you take a higher-res photo, using smaller-wavelength electrons lets you capture objects at much higher detail.
The other difference is that while normal cameras use a flash (or available light) to "see" their subjects, electron microscopes use a high powered beam of electrical radiation (the lab technicians frown on you calling it a "death-ray"). This makes electron microscopes way more complicated than normal cameras. It also makes them a lot more expensive (Phase One systems aside). The scope we used (a "desktop" model, which means it takes up an entire large desk and several nearby desks as well) retails for about $75,000. Other scopes in the lab run into the hundreds of thousands.
Gado Images Co-Founder Amy with the scope /Gado
Given the cost and complexity of electron microscopes, the process of using them is actually pretty straightforward. After a lot training from a friendly but somewhat skeptical lab tech ("who did you say your PI was again?"), you're given clearance to use the scope. First, you mount your sample on a special aluminum circle called a stub. You then use a measuring apparatus to precisely set the distance between your sample and the top of the scope. The tradeoff here is a familiar one; since the scope has a fixed aperture, moving the sample closer means more selective focus, but a shallower depth of field.
Once the sample is positioned, you insert it into the scope's chamber, and switch on an extremely loud, high-powered two stage pump. This sounds a bit like the love child of a vacuum cleaner and a turboprop engine. It voids most of the air from the scope's chamber, a process which takes a few minutes.
Once the scope is all set up, you open the microscopy software on an ancient PC (Windows XP anyone?). The interface looks like scanner software from the late 1990s, complete with needlessly large custom-styled buttons and friendly, Comic Sans-esque fonts. At this point, taking pictures is very much like using a camera. You can pan around the subject, zoom in and out, adjust focus, and save JPGs whenever you like.
Electron microscope image of a ballpoint pen tip (with colorization) at 50x magnification /Gado
For those not familiar with lab work, some parts of the process can be a bit intimidating. As you're working, for example, a man periodically walks around with an ominously-clicking Geiger counter and waves it around the scope to make sure you're not irradiating yourself. There's not much to worry about, really; modern electron microscopes are so well shielded that using one is about as dangerous as standing near a microwave oven.
The real concern, it turns out, is not in the scope but in the lab around it. At one point in our training, I put my camera bag down on a lab bench. The lab tech shifted uncomfortably and said "um, you might want to move that. " Turns out one of the chemicals used to prepare certain biological samples is liquefied uranium, which he was concerned may have been used on the bench. You'll be pleased to know that I stood in a dark room afterwards, and I didn't glow in the dark, even a little bit.
When you're done, you let air back into the chamber, remove your sample, take your files, and go. The basic process really is that simple. But then, so is the process of taking a photo; all you have to do is hit the shutter button, after all! The devil (and the artistry) is in the details.
Taking a great electron microscope image is just as challenging as taking a great photograph. Getting the depth of field, focus and other settings just right requires skill and a lot of practice. With microscopy, it also requires knowledge of the electrical properties of your sample, the proper energy level of the electron beam, and myriad other factors. The tech who helped us out had been working in his lab for years, and the director has been in the field for his entire career.
Plant root, with a root hair and particles of soil, at 5000x magnification /Gado
With high-end microscopy, things get even more complex. Our scope could zoom in to about 10,000x. That's still 10x better than your standard light microscope, and was plenty of magnification for our needs. But it's nowhere near the magnification of other equipment. Our lab's best scope could go up to 800,000x, and magnifications of 10 million times are possible. At this level, you can see individual viruses, cellular components, even single atoms.
To get to these magnifications, though, it's not just about the scope. Sample prep becomes the biggest challenge. First, you need an impossibly thin sample. This requires a machine called a microtome, which uses a knife made of diamond to shave off tiny pieces of whatever you're scanning.
For biological samples, you then need to dry them out completely via a process which uses multiple chemicals and takes the better part of a day. If your sample doesn't conduct electricity well, you have to coat it in a super-thin layer of gold. And to top it all off, everything you scan has to be frozen using liquid nitrogen. With high-end microscopy, like high-end studio photography, days or weeks of work have gone into the shoot before you even fire the shutter.
Spider's silk, at a magnification of 800x /Gado
In the end, our team was able to take more than 100 high-quality images. The next time you open a high school biology textbook or read a Buzzfeed article about "The Ten Different Kinds of Spider's Silk!" you may very well see our images. Beyond the images, though, our experience with electron microscopy reveals something even more fundamental about photography: experimenting with new mediums is always a great way to improve your craft.
New mediums allow you to re-evaluate things you do every day, and give you a chance to see your work from a new perspective. Taking pictures with electrons, for example, forces you to think about the limitations of light. Most photographers take it for granted that light is important, but how many stop to think about it at a particle level? Likewise, you probably think about depth of field all the time, but there's value in knowing that it relates to fundamental principles of physics, not just the dials on your EOS 5D.
So even if you're not going to take up microscopy, consider trying out a new medium. Build a pinhole camera and experiment with lensless photography. Borrow your friend's drone. If you shoot video, rent a high speed camera for the weekend and pop some water balloons. It's always valuable to learn a new skill, get outside your comfort zone, and hopefully take back some lessons you can apply to your everyday work. Or at least emerge with some pretty pictures of plants and a slight radioactive glow.
Thomas Smith is Co-Founder and CEO of Gado Images, a software and media company which uses innovative technologies to digitize and share the world’s visual history. The company works with archival collections to find unique, niche content and make it available to creatives worldwide.
. digitalrev.com2016-12-30 03:00