Initial Thoughts

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Initial Thoughts

This hypertext guide is designed to help you through the process of acquiring and processing images. The focus here will be on biological imaging - pictures that will help you do your job as a biologist.

Why are images important? The old saying goes "a picture is worth a thousand words". That's true to some extent, so in some ways an image is a way to be lazy. Other times, however, an image is necessary in order to convey your information to someone else, or even to discover new knowledge that you would not be able to uncover without the ability of the camera to freeze a moment in time. While plopping an image into a report may seem like an easy thing at the time, when one must produce the image in the first place it becomes a very different task.

What is the difference between photography and imaging? It used to be a simple distinction; photographs were made using a camera, film, and visible light - everything else (x-rays, computer graphics, scans, etc.) was an image. Digital photography and digital manipulation of photographs is changing all that, however, and the lines are blurring. I like to make this distinction - any graphic is an image; if it is a piece of film (or a print made from a negative) then it is a photograph. Although digital techniques may completely replace film in a few years, we will begin by mastering film for the simple reason that anyone that can produce an excellent image on film will be able to do so digitally as well.

What about biological imaging? Biology is a visual science; it is often important to be able to picture an organism, a piece of equipment, or a procedure. Imaging is a tool - not an end in itself. In some ways that separates you from an artist, where the image (and the emotions and message it conveys) is everything. Don't get me wrong - there is plenty of room for artistry in biological imaging, but artistry must come second to clearly presenting the information you need to convey. Traditionally, biological imaging was done by the scientists themselves, usually in the form of illustrations drawn out by hand. Technology made imaging more accessible to those scientists who lacked the talent to draw. Today, biological imaging is done primarily by three groups of individuals - the scientists themselves, as time and skill permit, by biological illustrators, often working on commission, and by technicians who operate specialized equipment such as electron microscopes. Your career might take you down any of these paths, but in all cases a good working knowledge of the basics of imaging will stand you in good stead - whether you need to produce the images yourself, or whether you simply need to communicate clearly to someone else what it is that you want in an image.

Although technology makes it ever easier to get a good image onto paper (or silicon, magnetic strips, whatever), it is still the case that some skill and artistry are involved. Like anything else, it takes practice. Even after years of practice, you may not always get exactly what you expect or need. Don't let this discourage you. In my case, I started taking pictures in high school. With the simple cameras I was using, I woud usually get back a roll of slides with less than perfect results. Five or 6 of the pictures would be blank - either grossly under or overexposed. Of the rest, only 5 or 6 would have a good exposure, and of these, 1 or 2 would be out-of-focus. Composition? Well, maybe 1 of the 3 or 4 technically good slides would have a really good composition.

So, with a simple camera I was lucky to get one really good slide, plus a half dozen or so that I could use. Not very good. In college, I got a camera which had "automatic" exposure; a computer in the camera could calulate the "proper" lens opening and shutter speed and set the camera accordingly. Results? Instead of 5 or 6 good exposures I would have 30 good exposures and 5 or 6 bad ones. Blanks were largely a thing of the past. Other mistakes became more apparent, though. Focus was still a problem, and blurry pictures from camera or subject movement were common. With that camera, I could count on 5 or 6 really good slides and 30 usable ones. Much better, but it still took a roll of film to get 5 good pictures.

Autofocus was the next evolution in cameras. Coupled with better automatic exposure systems, I now get 20 or so really good slides per roll, and the rest aren't that bad (my standards of good and bad are always evolving as well - what I consider a bad picture today would have been a good one 20 years ago). There will still be a half-dozen or so slides on a roll that just don't work.

Overall, I'd say that technology has made most of the improvement in my picture taking. That means that with the equipment available today, just about anyone can start off taking pretty good pictures most of the time, at least once they learn to avoid some simple mistakes. Of course, doing biological imaging is a bit tougher that taking snapshots on a vacation. For one, many of the subjects don't take direction well!