Confessions of a Light Microscopist: The Man in Black

Black velvet folds

In this post we continue our Confessions of a Light Microscopist series—stories about unique individuals who take their craft to the highest possible level—a level that may be considered unreasonable by most estimates, but we will let you be the judge of that. This confession comes from a shadowy figure who prefers to work in complete darkness in an effort to achieve the ultimate photomicrographs—let’s meet The Man in Black.

The Confession: “When I’m making photographs through the microscope I work in complete darkness. I make sure that any reflective material on my microscope has been painted with flat black paint, the walls and ceiling of my work area are shrouded with black fabric, and of course I’m dressed in black clothing.”

But of course, who wouldn’t do that?!

You might be thinking that surely the photomicrographs taken in your well-lit, maybe even sunny, lab are good enough, and in most cases you would probably be correct—they are good enough. However, there may be occasions when you need to produce a high quality photomicrograph, let’s say, for a publication, or you are thinking of entering a photomicrography competition. In these situations, it’s probably a good idea to up your game. After reading this article, you may be inclined to at least walk over to the light switch and turn out the lights in your lab before making a photomicrograph.

Lights Out

Turning out the room lights before capturing an image has made a noticeable difference in the quality of my photomicrographs. In paying closer attention to my usually well-lit surroundings, it was apparent that some of the digital cameras I used are incredibly sensitive in picking up stray room light, especially from overhead lighting.

I first noticed “room light pollution” while using an Olympus DP70 digital camera on an Olympus SZX-10 stereomicroscope. The image below is a photograph of my computer monitor. This image was produced without any form of illumination being provided to the system other than the overhead room lights. You can actually see the individual ceiling light fixtures being picked up from the camera. It seemed that most of the stray light was entering the system via the eyepieces of the stereomicroscope.

microscope camera ambient light
Room light pollution displayed on the computer monitor. No microscope illumination is being provided to the camera.

Next, I tried making photomicrographs in a room that had far fewer overhead lights. This time I was using an Olympus SZX-10 stereomicroscope with a Nikon Fi3 digital camera. I wanted to understand where most of the room light pollution was coming from…was it entering mostly through the objective, or was it coming through the eyepieces? First, I covered the 1X objective on the stereomicroscope using a black plastic dust cap in an effort to see how much room light was entering the eyepieces. You can see from the photomicrograph that not much light seemed to be entering the system through the eyepieces. However, you can still make out the shape of the fluorescent light from the light fixture overhead (indicated by the blue arrow). The overall field of view has a sick green color, as well.

ambient light through microscope
Overhead room lighting entering the stereomicroscope system via the eyepieces, 25X.

Next, I removed the plastic dust cap from the 1X objective and covered the eyepieces to see how much of the room lights were being picked up from the objective only. The image below is the resulting image captured with no illumination being provided to the system other than the overhead room lights. As you can see, the sample is completely illuminated and has an overall yellow appearance.

stereomicroscope ambient light
Stereomicroscope image with no illumination coming to the sample other than the overhead room lighting, 25X.

My initial thoughts were that the stereomicroscope would likely pick up more light pollution from the room lighting as compared to a traditional compound light microscope because of its large diameter objective and much greater working distance. My assumption was incorrect. In fact, you might argue that the room light pollution is as bad, or maybe even worse, on the compound microscope; I was using an Olympus BX-51 polarized light microscope. Below are several captured images to illustrate this point:

The above image is showing the illumination from the overhead fluorescent lighting entering the system through the eyepieces and 10X objective. The microscope illuminator has been turned off so that there is no deliberate illumination coming to the microscope. Again, you can almost make out the rectangular shape of the ceiling light fixture coming through the eyepieces and then being directed up to the camera. This photomicrograph was captured at 100X total magnification.

The image below is the same field of view, but this time with the three-position (selection lever) light path selector knob on the trinocular head pulled completely out, directing all of the light to the camera. In other words, there is no light entering the system through the microscope’s eyepieces. The only illumination being provided to the microscope is from the overhead room lights.

stereomicroscope ambient light

The image below was captured with all of the overhead room lights off, yielding a completely black field of view.

stereomicroscope ambient light room lights off

Turning out the room lights is a good and easy to-do first step, but are there other measures that can be taken to darken your environment even more? Below are some ways that you can level-up, let’s take a look.

Donning All Your Black Apparel

Just like turning out the room lights, this next measure takes hardly any effort at all…just go into your closet and find something black to wear and then begin channeling your inner La Femme Nikita. La Femme Nikita was a 90’s television spy drama, all of the characters wore mostly black clothing, and the music featured in each episode was cool too—but I digress. The Man in Black suggests wearing black jeans, a black turtleneck shirt, and a black cap of some sort, preferably a knit one. There is an alternative to dressing head-to-toe in black; more on that in a bit.

Paint it Black

Next, you will have to take a good look at your microscope and identify any shiny or reflective surfaces. Looking at your microscope from different perspectives helps to find any highly-reflective surfaces, many usually hidden from your normal point of view. Using flat black paint and a small paintbrush, paint all of these surfaces with a couple of coats. Below is a picture looking up from the stage of the Olympus BX-51. You can see one of the two metal pins located on the underside of the reflected light attachment. These pins hold a plastic UV-cut plate, a shield of sorts for when you are doing fluorescence microscopy work.

BX-51 underside
The view, looking up, from the Olympus BX-51 stage.

If you take a good look at the surface of these pins, you’ll notice that they aren’t really that shiny; they have a brushed nickel finish. Rather than cover these surfaces with flat black paint, I tried a black Sharpie™, which seemed to work well; however, when it comes to blackening anything that has more of a chrome-like finish, the Sharpie pen produces an equally shiny black finish.

UV shield pin blackened with Sharpie
UV shield pin blackened with Sharpie.

Traditionally, many microscope objectives are manufactured with a highly-reflective chrome-like sleeve. Rather than using flat black paint to blacken the entire chrome surface of the objective, The Man in Black recommends applying flock paper to the objectives.

Olympus achromat objectives with chrome-like finish
Olympus achromat objectives with chrome-like finish.

Flock paper is often used by telescope enthusiasts to blacken the inside tube of a homemade telescope. The flock paper is made up of a mat of small black fibers with an adhesive backing, which makes it ideal for cutting into whatever shape and size you need. The adhesive isn’t too aggressive and can be easily removed at a later time.

The idea of blacking out the objective’s sleeve is not something new. The Man in Black sent me this image of an older Leitz projection microscope (1960s) showing the objectives shrouded in specially-designed flat black metallic sleeves. The two things that look like eyepieces at the top of the case are projection eyepieces for projecting the image from the microscope onto a screen or wall for instructional purposes.

Leitz PRADO projection microscope
Leitz projection microscope.

Wrapping each objective in the flock paper was relatively easy. I basically tried to mimic the design of the Leitz objective shield, extending the flock paper so that it was flush with the end of each objective.

Achromat objectives wrapped in flock paper
Olympus achromat objectives after applying flock paper.

After wrapping each objective, I noticed that their front portions were still very shiny and would likely introduce unwanted reflections onto the sample. Trying to cover the ends of each objective with the flock paper proved difficult because of the geometry of each objective’s ends.

Wrapped microscope objectives on nosepiece
Wrapped objectives without flat black paint.

A far easier solution was to use some flat black paint. In my case, I used acrylic paint because I wanted the option of being able to easily remove the paint at a later time. A more permanent solution would involve an oil-based paint with better adhering properties. Since most microscope objective sleeves are purely decorative, they can be easily removed from the objective and the ends can be spray painted for a smoother finish.

Painted ends of the achromat objectives
Painted ends of the achromat objectives using flat black acrylic paint.
Painted and wrapped objectives on the nosepiece
Painted and wrapped objectives on the nosepiece.

In going through this process I noticed that some of the more highly corrected objectives, like plan fluorites or plan apochromats, are manufactured with a much darker and less reflective finish than their less expensive achromat counterparts. I would have to assume that this is done purely for better imaging purposes.

Finishes on microscope objectives
Comparing manufacturers’ finishes of the (left to right) Olympus achromat, fluorite, and apochromat objectives.

A Room Without a View

Now that the microscope parts have been sufficiently blackened, it is time to shroud the area around the microscope with black fabric. It was suggested that I go to the fabric store and purchase several yards of black flannel material. The black flannel was used to create a sort of tent-like area surrounding the microscope, blocking out any light coming from a computer monitor, microscope illuminator, and reflections from the ceiling tiles, above. Of course you will need to block any sunlight coming in from the windows, but ideally your setup would be in a room without any windows. Incidentally, when McCrone Associates’ new laboratories were built, the light microscopy work areas were placed in the middle of the complex to avoid any light coming in from windows.

light-proof your microscope
Notice the black fabric shrouding the left side of the microscope, blocking any light coming from the monitor and fiber optic illuminator.

Photo-mic-Drop

After putting on black clothing, blacking out the microscope objectives and parts, and building a black tent out of flannel fabric, was it all worth the effort? Well, as they say, “the proof is in the pudding.” Many years ago, The Man in Black entered a photomicrography competition with the idea of submitting several photomicrographs in a number of different categories. The competition was to be judged by a panel of professional microscopists. The categories in the competition included black and white prints, 35 mm color transparency, and color prints. All of the entries were submitted anonymously so that the judges would not be influenced by knowing the name of the contestants. After the judging was over, the first, second, and third place winning photomicrographs were displayed on a table in each of the three categories. The judges then flipped over the photomicrographs to reveal the contestants’ names that appeared on the back of each entry. The Man in Black took first, second, and third place in every category. He ran the table, and as such, later recused himself from entering any further photomicrography competitions. He claims his real advantage over the other participants was capturing his images, on film at the time, in total darkness.

A Funny Thing Happened on the Way to Class the Other Day

About six months ago, during our Pigment Identification course, I noticed that just about every time I passed the classroom the students and the instructor were working with the lights out. Of course the first thing that came to mind was the confession from The Man in Black. Finally, during one of the coffee breaks I asked the students why they were having our instructor teach the course in a darkened room? Up until this time the course had never been taught in this way. All of the students happened to be from the same art conservation department at an East Coast museum. They said that they always work in the dark because you have less interference from the room lights when viewing your sample through the microscope. I went on to tell them that I was writing this article, and just out of curiosity asked if they wear black clothing while working in their darkened laboratories. Their response was that not all of them wear black, but that some of their colleagues wear black laboratory coats as a way of darkening what they are wearing. Remember earlier I mentioned a workaround to showing up to the lab wearing all black? A black laboratory coat fits the bill. Pure genius! As it turns out, The Man in Black was not alone; using your microscope in complete darkness is definitely a thing.

Fade to Black

In a parting comment, The Man in Black said that there is something truly magical about being alone in complete darkness with only the specimen fully illuminated on the microscope stage. This sea of darkness transcends aesthetics and good technique, it creates the perfect environment where you cannot help becoming caught up in the beauty of the moment, where only you and the specimen exist…

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