So, a while ago I extolled the virtues of microscopy. Well, now that I’ve gone through the process of taking microscopic images of a number of samples at the Image Permanence Institute (IPI) I take it all back – microscopy sucks. OK, it doesn’t really suck, but it does require a certain level of precision and patience to cut, prep and observe microscopic samples of film and tape.
Before being let loose on the equipment, I was primed in the usage and benefits of observing images (still and moving image formats) under the microscope. Essentially, the microscope offers the opportunity to see the structure of any given format, and can distinguish the different materials that comprise a piece of, for example, paper or film.
I pulled a clever looking book off the IPI shelves to help me understand the practice even further. This was my first mistake. While I’m sure that Douglas B. Murphy’s Fundamentals of Light Microscopy and Electronic Imaging (NYC: Wiley-Liss, 2001) is a comprehensive and invaluable textbook for students of imaging science, it mostly went over my head. However, Murphy did neatly distill why we use microscopes as a means of manipulating light:
It is useful to think of light as a probe that can be used to determine the structure of objects viewed under a microscope.
To put this back into context, what the IPI does in its microscopy lab is probe images, in order to understand the structure of an artefact, so they can gain a deeper understanding of its peculiar characteristics.
Once the book work was done, I was trained in cutting microscopic samples, starting with a standard digital print on consumer ink jet paper (I do not know the exact brand). First, I cut a small strip, making sure that the sample included an area of high density and an area of low density (as in thick dense ink and thin sparse ink). Then I had to carefully secure the sample to a piece of equipment called a microtome (1). I then used the microtome to measure and splice teeny weeny sections of paper. Using a set of dentistry tools (3) I finagled these tiny samples from the microtome to a slide.
Because cutting sections is so difficult, I had to get five or six samples onto the slide, to make sure I would have one that wasn’t mashed up by the blade. After immersing the samples in a solution (causing the samples to swell and thus easier to see under the lens), I mounted the slide under the microscope (2). It took some time to adjust the settings, objectives and focus to get a good view of the cross section of paper; once I had it in my sight, though, I was amazed to see the clarity in the different layers of the paper.
The next stage in the process was to take images from the sample through the camera mounted on the microscope. I had to take a few exposures, because the section was so magnified that it was impossible to get it all in focus at once. These exposures were then post-processed to correct the white balance, stacked into a single image in Photoshop, and a sharpening filter was added just to emphasise the structure of the layers. And then, the fun bit – looking at the finished image:
Whoah, right? That is bog standard glossy printer paper. To the naked eye, paper is a one-layer substance, maybe with a glossy sheen on top; here you can see the pulp, the binders, the sealants and the ink… Microscopy really forces you to think beyond what the eye can see.
So, at this point I was hooked and excited to see some moving picture film through the lens. Here is a sample from a standard chromogenic print (i.e. the sort you get in the cinema). You can actually see the magenta, cyan and yellow layers of emulsion. Fun fact: get a piece of reversal film under the microscope, like Kodachrome, and the colour layers are in a different order (yellow, magenta, cyan) just like a colour negative.
A week or so later, when my supervisor asked if I could look at some cross-sections of magnetic tape under the microscope, I was like ‘Pfft! Of course I can!’. That was my big mistake. Tape is much harder to sample than acetate film, for a couple of reasons:
1. Tape formats are generally much thinner than film, and if you do manage to cut a workable section it is almost invisible.
2. The polyester substrate is far more resistant to slicing and cutting than acetate or paper materials.
I began with 2″ quad tape, and that was not so bad. You can see that the sealant on the bottom is a little rough, and there is a bit of abrasion in the base, but it’s a relatively clean cut and you can see the layers. You can also see that the magnetic material and the binder make up a bigger proportion of the tape compared to the emulsion in the acetate print.
Feeling indestructible, I sliced up some 1″ videotape:
Oh dear, not very clear at all (and with a lot of digital artefacts that cropped up in post-processing). Still undeterred, I attempted a piece of U-matic tape. Well…
I am truly ashamed and humbled… I couldn’t even get the sample straight or in focus, it was that thin and difficult.
So, the moral of this story is patience. You can’t rush microscopy, and you can’t master it in a few short weeks. And yet it was also empowering to learn a new skill, even if I have not conquered it completely. Microscopes are more likely to be found in biology labs than film archives, and I am lucky to be somewhere as unique as the IPI, and that I’m learning to appreciate the moving image artefacts I work with on a deeper, structural level (even if I still curse magnetic tape in all its forms!).
Disclaimer: no unique recordings were destroyed in the making of this blog post.